Line Coverage for Module :
prim_reg_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T6 T1 T14
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T6 T1 T14
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T6 T1 T14
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T6 T1 T14
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T6 T1 T14
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T6 T1 T14
135 1/1 txn_bits_q <= '0;
Tests: T6 T1 T14
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Module :
prim_reg_cdc ( parameter DataWidth=16,ResetVal,BitMask=65535,DstWrReq=0,TxnWidth=3 + DataWidth=12,ResetVal=0,BitMask=4095,DstWrReq=0,TxnWidth=3 + DataWidth=8,ResetVal,BitMask=255,DstWrReq=0,TxnWidth=3 + DataWidth=14,ResetVal=0,BitMask=16383,DstWrReq=0,TxnWidth=3 + DataWidth=17,ResetVal=2000,BitMask=131071,DstWrReq=0,TxnWidth=3 + DataWidth=7,ResetVal=0,BitMask=119,DstWrReq=0,TxnWidth=3 + DataWidth=5,ResetVal=0,BitMask=31,DstWrReq=0,TxnWidth=3 + DataWidth=32,ResetVal=0,BitMask=-1,DstWrReq=0,TxnWidth=3 + DataWidth=4,ResetVal=0,BitMask=15,DstWrReq=0,TxnWidth=3 )
Cond Coverage for Module self-instances :
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T4,T6,T1 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T4,T6,T1 |
1 | 1 | Covered | T4,T6,T1 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T4,T6,T1 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T4,T6,T1 |
1 | 1 | Covered | T4,T6,T1 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Cond Coverage for Module :
prim_reg_cdc ( parameter DataWidth=1,ResetVal=0,BitMask=1,DstWrReq=0,TxnWidth=3 + DataWidth=1,ResetVal=0,BitMask=1,DstWrReq=1,TxnWidth=3 )
Cond Coverage for Module self-instances :
| Total | Covered | Percent |
Conditions | 16 | 14 | 87.50 |
Logical | 16 | 14 | 87.50 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T8,T11,T13 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T8,T11,T13 |
1 | 1 | Covered | T8,T11,T13 |
LINE 123
EXPRESSION (src_wd_i & BitMask)
----1--- ---2---
-1- | -2- | Status | Tests |
0 | - | Covered | T8,T11,T13 |
1 | - | Covered | T8,T11,T13 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Covered | T8,T11,T13 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T8,T11,T13 |
1 | 1 | Covered | T8,T11,T13 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Not Covered | |
1 | 1 | Covered | T1,T2,T3 |
Branch Coverage for Module :
prim_reg_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T6,T1,T14 |
0 |
0 |
1 |
Covered |
T6,T1,T14 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T6,T1,T14 |
0 |
0 |
1 |
Covered |
T6,T1,T14 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Module :
prim_reg_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
2147483647 |
97991511 |
0 |
0 |
T1 |
114854 |
917 |
0 |
0 |
T2 |
0 |
449 |
0 |
0 |
T6 |
56928 |
459 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T9 |
0 |
88 |
0 |
0 |
T10 |
55652 |
328 |
0 |
0 |
T12 |
0 |
123 |
0 |
0 |
T14 |
51486 |
0 |
0 |
0 |
T15 |
245841 |
0 |
0 |
0 |
T16 |
583785 |
6182 |
0 |
0 |
T17 |
96600 |
0 |
0 |
0 |
T18 |
152874 |
0 |
0 |
0 |
T19 |
633918 |
1432 |
0 |
0 |
T20 |
783168 |
0 |
0 |
0 |
T21 |
222288 |
715 |
0 |
0 |
T22 |
126096 |
0 |
0 |
0 |
T23 |
45481 |
0 |
0 |
0 |
T28 |
351274 |
0 |
0 |
0 |
T29 |
226502 |
0 |
0 |
0 |
T31 |
0 |
3204 |
0 |
0 |
T32 |
0 |
11583 |
0 |
0 |
T33 |
0 |
356 |
0 |
0 |
T34 |
735021 |
638 |
0 |
0 |
T35 |
0 |
5015 |
0 |
0 |
T36 |
0 |
573 |
0 |
0 |
T54 |
0 |
3208 |
0 |
0 |
T60 |
0 |
6544 |
0 |
0 |
T61 |
0 |
3409 |
0 |
0 |
T62 |
0 |
10392 |
0 |
0 |
T63 |
0 |
3678 |
0 |
0 |
T64 |
0 |
3733 |
0 |
0 |
T65 |
70926 |
0 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
274292552 |
252196734 |
0 |
0 |
T1 |
16592 |
2992 |
0 |
0 |
T4 |
16864 |
3264 |
0 |
0 |
T5 |
14416 |
816 |
0 |
0 |
T6 |
15470 |
1870 |
0 |
0 |
T14 |
26928 |
13328 |
0 |
0 |
T15 |
17068 |
3468 |
0 |
0 |
T16 |
26418 |
12818 |
0 |
0 |
T17 |
14586 |
986 |
0 |
0 |
T18 |
13838 |
238 |
0 |
0 |
T23 |
15470 |
1870 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
2147483647 |
107254 |
0 |
0 |
T1 |
114854 |
1 |
0 |
0 |
T2 |
0 |
1 |
0 |
0 |
T6 |
56928 |
1 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T9 |
0 |
1 |
0 |
0 |
T10 |
55652 |
1 |
0 |
0 |
T12 |
0 |
1 |
0 |
0 |
T14 |
51486 |
0 |
0 |
0 |
T15 |
245841 |
0 |
0 |
0 |
T16 |
583785 |
7 |
0 |
0 |
T17 |
96600 |
0 |
0 |
0 |
T18 |
152874 |
0 |
0 |
0 |
T19 |
633918 |
1 |
0 |
0 |
T20 |
783168 |
0 |
0 |
0 |
T21 |
222288 |
1 |
0 |
0 |
T22 |
126096 |
0 |
0 |
0 |
T23 |
45481 |
0 |
0 |
0 |
T28 |
351274 |
0 |
0 |
0 |
T29 |
226502 |
0 |
0 |
0 |
T31 |
0 |
8 |
0 |
0 |
T32 |
0 |
7 |
0 |
0 |
T33 |
0 |
1 |
0 |
0 |
T34 |
735021 |
2 |
0 |
0 |
T35 |
0 |
12 |
0 |
0 |
T36 |
0 |
2 |
0 |
0 |
T54 |
0 |
7 |
0 |
0 |
T60 |
0 |
8 |
0 |
0 |
T61 |
0 |
8 |
0 |
0 |
T62 |
0 |
6 |
0 |
0 |
T63 |
0 |
8 |
0 |
0 |
T64 |
0 |
8 |
0 |
0 |
T65 |
70926 |
0 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
2147483647 |
2147483647 |
0 |
0 |
T1 |
3905036 |
3902690 |
0 |
0 |
T4 |
1858134 |
1855754 |
0 |
0 |
T5 |
2240838 |
2237812 |
0 |
0 |
T6 |
1935552 |
1933308 |
0 |
0 |
T14 |
1750524 |
1747498 |
0 |
0 |
T15 |
8358594 |
8356112 |
0 |
0 |
T16 |
6616230 |
6613986 |
0 |
0 |
T17 |
1094800 |
1092930 |
0 |
0 |
T18 |
1732572 |
1730328 |
0 |
0 |
T23 |
1546354 |
1543498 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_wkup_status_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T8 T11 T13
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T8 T11 T13
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T8 T11 T13
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T8 T11 T13
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T8 T11 T13
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T1 T2 T3
135 1/1 txn_bits_q <= '0;
Tests: T1 T2 T3
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_wkup_status_cdc
| Total | Covered | Percent |
Conditions | 16 | 14 | 87.50 |
Logical | 16 | 14 | 87.50 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T8,T11,T13 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T8,T11,T13 |
1 | 1 | Covered | T8,T11,T13 |
LINE 123
EXPRESSION (src_wd_i & BitMask)
----1--- ---2---
-1- | -2- | Status | Tests |
0 | - | Covered | T69,T39,T40 |
1 | - | Covered | T8,T11,T13 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Covered | T8,T11,T13 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T8,T11,T13 |
1 | 1 | Covered | T8,T11,T13 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Not Covered | |
1 | 1 | Covered | T1,T2,T3 |
Branch Coverage for Instance : tb.dut.u_reg.u_wkup_status_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T8,T11,T13 |
0 |
0 |
1 |
Covered |
T8,T11,T13 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T8,T11,T13 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_wkup_status_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1122241 |
0 |
0 |
T8 |
132162 |
248 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
1358 |
0 |
0 |
T13 |
0 |
457 |
0 |
0 |
T32 |
373680 |
0 |
0 |
0 |
T36 |
0 |
339 |
0 |
0 |
T37 |
0 |
1538 |
0 |
0 |
T44 |
0 |
2440 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T70 |
0 |
895 |
0 |
0 |
T71 |
0 |
653 |
0 |
0 |
T72 |
0 |
711 |
0 |
0 |
T73 |
0 |
492 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1165 |
0 |
0 |
T8 |
132162 |
1 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
1 |
0 |
0 |
T13 |
0 |
1 |
0 |
0 |
T32 |
373680 |
0 |
0 |
0 |
T36 |
0 |
1 |
0 |
0 |
T37 |
0 |
4 |
0 |
0 |
T44 |
0 |
9 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T70 |
0 |
1 |
0 |
0 |
T71 |
0 |
1 |
0 |
0 |
T72 |
0 |
1 |
0 |
0 |
T73 |
0 |
1 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_ec_rst_ctl_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T6 T1 T14
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T6 T1 T14
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T6 T1 T14
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T6 T1 T14
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T6 T1 T14
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T6 T1 T14
135 1/1 txn_bits_q <= '0;
Tests: T6 T1 T14
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_ec_rst_ctl_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T6,T1,T14 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T6,T1,T14 |
1 | 1 | Covered | T6,T1,T14 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T6,T1,T14 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T6,T1,T14 |
1 | 1 | Covered | T6,T1,T14 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_ec_rst_ctl_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T6,T1,T14 |
0 |
0 |
1 |
Covered |
T6,T1,T14 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T6,T1,T14 |
0 |
0 |
1 |
Covered |
T6,T1,T14 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_ec_rst_ctl_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1730151 |
0 |
0 |
T1 |
114854 |
899 |
0 |
0 |
T2 |
0 |
435 |
0 |
0 |
T6 |
56928 |
435 |
0 |
0 |
T9 |
0 |
70 |
0 |
0 |
T14 |
51486 |
258 |
0 |
0 |
T15 |
245841 |
0 |
0 |
0 |
T16 |
194595 |
0 |
0 |
0 |
T17 |
32200 |
0 |
0 |
0 |
T18 |
50958 |
0 |
0 |
0 |
T19 |
211306 |
1428 |
0 |
0 |
T20 |
261056 |
0 |
0 |
0 |
T21 |
0 |
695 |
0 |
0 |
T23 |
45481 |
0 |
0 |
0 |
T33 |
0 |
343 |
0 |
0 |
T65 |
0 |
238 |
0 |
0 |
T77 |
0 |
187 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1890 |
0 |
0 |
T1 |
114854 |
1 |
0 |
0 |
T2 |
0 |
1 |
0 |
0 |
T6 |
56928 |
1 |
0 |
0 |
T9 |
0 |
1 |
0 |
0 |
T14 |
51486 |
1 |
0 |
0 |
T15 |
245841 |
0 |
0 |
0 |
T16 |
194595 |
0 |
0 |
0 |
T17 |
32200 |
0 |
0 |
0 |
T18 |
50958 |
0 |
0 |
0 |
T19 |
211306 |
1 |
0 |
0 |
T20 |
261056 |
0 |
0 |
0 |
T21 |
0 |
1 |
0 |
0 |
T23 |
45481 |
0 |
0 |
0 |
T33 |
0 |
1 |
0 |
0 |
T65 |
0 |
1 |
0 |
0 |
T77 |
0 |
1 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_ulp_ac_debounce_ctl_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T28 T8 T11
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T28 T8 T11
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T28 T8 T11
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T28 T8 T11
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T28 T8 T11
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T28 T8 T11
135 1/1 txn_bits_q <= '0;
Tests: T28 T8 T11
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_ulp_ac_debounce_ctl_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T28,T8,T11 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T28,T8,T11 |
1 | 1 | Covered | T28,T8,T11 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T28,T8,T11 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T28,T8,T11 |
1 | 1 | Covered | T28,T8,T11 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_ulp_ac_debounce_ctl_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T28,T8,T11 |
0 |
0 |
1 |
Covered |
T28,T8,T11 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T28,T8,T11 |
0 |
0 |
1 |
Covered |
T28,T8,T11 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_ulp_ac_debounce_ctl_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
954931 |
0 |
0 |
T2 |
63505 |
0 |
0 |
0 |
T3 |
374218 |
0 |
0 |
0 |
T8 |
0 |
265 |
0 |
0 |
T9 |
15197 |
0 |
0 |
0 |
T11 |
0 |
2829 |
0 |
0 |
T13 |
0 |
990 |
0 |
0 |
T28 |
175637 |
236 |
0 |
0 |
T30 |
62131 |
0 |
0 |
0 |
T31 |
84510 |
0 |
0 |
0 |
T35 |
0 |
412 |
0 |
0 |
T70 |
0 |
1586 |
0 |
0 |
T71 |
0 |
1814 |
0 |
0 |
T72 |
0 |
1711 |
0 |
0 |
T78 |
0 |
476 |
0 |
0 |
T79 |
0 |
3342 |
0 |
0 |
T80 |
196791 |
0 |
0 |
0 |
T81 |
118182 |
0 |
0 |
0 |
T82 |
337286 |
0 |
0 |
0 |
T83 |
54981 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1016 |
0 |
0 |
T2 |
63505 |
0 |
0 |
0 |
T3 |
374218 |
0 |
0 |
0 |
T8 |
0 |
1 |
0 |
0 |
T9 |
15197 |
0 |
0 |
0 |
T11 |
0 |
2 |
0 |
0 |
T13 |
0 |
2 |
0 |
0 |
T28 |
175637 |
1 |
0 |
0 |
T30 |
62131 |
0 |
0 |
0 |
T31 |
84510 |
0 |
0 |
0 |
T35 |
0 |
1 |
0 |
0 |
T70 |
0 |
2 |
0 |
0 |
T71 |
0 |
3 |
0 |
0 |
T72 |
0 |
2 |
0 |
0 |
T78 |
0 |
1 |
0 |
0 |
T79 |
0 |
2 |
0 |
0 |
T80 |
196791 |
0 |
0 |
0 |
T81 |
118182 |
0 |
0 |
0 |
T82 |
337286 |
0 |
0 |
0 |
T83 |
54981 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_ulp_lid_debounce_ctl_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T28 T8 T11
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T28 T8 T11
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T28 T8 T11
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T28 T8 T11
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T28 T8 T11
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T28 T8 T11
135 1/1 txn_bits_q <= '0;
Tests: T28 T8 T11
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_ulp_lid_debounce_ctl_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T28,T8,T11 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T28,T8,T11 |
1 | 1 | Covered | T28,T8,T11 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T28,T8,T11 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T28,T8,T11 |
1 | 1 | Covered | T28,T8,T11 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_ulp_lid_debounce_ctl_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T28,T8,T11 |
0 |
0 |
1 |
Covered |
T28,T8,T11 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T28,T8,T11 |
0 |
0 |
1 |
Covered |
T28,T8,T11 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_ulp_lid_debounce_ctl_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
956936 |
0 |
0 |
T2 |
63505 |
0 |
0 |
0 |
T3 |
374218 |
0 |
0 |
0 |
T8 |
0 |
258 |
0 |
0 |
T9 |
15197 |
0 |
0 |
0 |
T11 |
0 |
2813 |
0 |
0 |
T13 |
0 |
974 |
0 |
0 |
T28 |
175637 |
234 |
0 |
0 |
T30 |
62131 |
0 |
0 |
0 |
T31 |
84510 |
0 |
0 |
0 |
T35 |
0 |
401 |
0 |
0 |
T70 |
0 |
1568 |
0 |
0 |
T71 |
0 |
1808 |
0 |
0 |
T72 |
0 |
1692 |
0 |
0 |
T78 |
0 |
474 |
0 |
0 |
T79 |
0 |
3316 |
0 |
0 |
T80 |
196791 |
0 |
0 |
0 |
T81 |
118182 |
0 |
0 |
0 |
T82 |
337286 |
0 |
0 |
0 |
T83 |
54981 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
984 |
0 |
0 |
T2 |
63505 |
0 |
0 |
0 |
T3 |
374218 |
0 |
0 |
0 |
T8 |
0 |
1 |
0 |
0 |
T9 |
15197 |
0 |
0 |
0 |
T11 |
0 |
2 |
0 |
0 |
T13 |
0 |
2 |
0 |
0 |
T28 |
175637 |
1 |
0 |
0 |
T30 |
62131 |
0 |
0 |
0 |
T31 |
84510 |
0 |
0 |
0 |
T35 |
0 |
1 |
0 |
0 |
T70 |
0 |
2 |
0 |
0 |
T71 |
0 |
3 |
0 |
0 |
T72 |
0 |
2 |
0 |
0 |
T78 |
0 |
1 |
0 |
0 |
T79 |
0 |
2 |
0 |
0 |
T80 |
196791 |
0 |
0 |
0 |
T81 |
118182 |
0 |
0 |
0 |
T82 |
337286 |
0 |
0 |
0 |
T83 |
54981 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_ulp_pwrb_debounce_ctl_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T28 T8 T11
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T28 T8 T11
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T28 T8 T11
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T28 T8 T11
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T28 T8 T11
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T28 T8 T11
135 1/1 txn_bits_q <= '0;
Tests: T28 T8 T11
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_ulp_pwrb_debounce_ctl_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T28,T8,T11 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T28,T8,T11 |
1 | 1 | Covered | T28,T8,T11 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T28,T8,T11 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T28,T8,T11 |
1 | 1 | Covered | T28,T8,T11 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_ulp_pwrb_debounce_ctl_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T28,T8,T11 |
0 |
0 |
1 |
Covered |
T28,T8,T11 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T28,T8,T11 |
0 |
0 |
1 |
Covered |
T28,T8,T11 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_ulp_pwrb_debounce_ctl_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
945640 |
0 |
0 |
T2 |
63505 |
0 |
0 |
0 |
T3 |
374218 |
0 |
0 |
0 |
T8 |
0 |
251 |
0 |
0 |
T9 |
15197 |
0 |
0 |
0 |
T11 |
0 |
2798 |
0 |
0 |
T13 |
0 |
952 |
0 |
0 |
T28 |
175637 |
232 |
0 |
0 |
T30 |
62131 |
0 |
0 |
0 |
T31 |
84510 |
0 |
0 |
0 |
T35 |
0 |
390 |
0 |
0 |
T70 |
0 |
1555 |
0 |
0 |
T71 |
0 |
1802 |
0 |
0 |
T72 |
0 |
1672 |
0 |
0 |
T78 |
0 |
466 |
0 |
0 |
T79 |
0 |
3283 |
0 |
0 |
T80 |
196791 |
0 |
0 |
0 |
T81 |
118182 |
0 |
0 |
0 |
T82 |
337286 |
0 |
0 |
0 |
T83 |
54981 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
995 |
0 |
0 |
T2 |
63505 |
0 |
0 |
0 |
T3 |
374218 |
0 |
0 |
0 |
T8 |
0 |
1 |
0 |
0 |
T9 |
15197 |
0 |
0 |
0 |
T11 |
0 |
2 |
0 |
0 |
T13 |
0 |
2 |
0 |
0 |
T28 |
175637 |
1 |
0 |
0 |
T30 |
62131 |
0 |
0 |
0 |
T31 |
84510 |
0 |
0 |
0 |
T35 |
0 |
1 |
0 |
0 |
T70 |
0 |
2 |
0 |
0 |
T71 |
0 |
3 |
0 |
0 |
T72 |
0 |
2 |
0 |
0 |
T78 |
0 |
1 |
0 |
0 |
T79 |
0 |
2 |
0 |
0 |
T80 |
196791 |
0 |
0 |
0 |
T81 |
118182 |
0 |
0 |
0 |
T82 |
337286 |
0 |
0 |
0 |
T83 |
54981 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_key_invert_ctl_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T4 T29 T30
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T4 T29 T30
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T4 T29 T30
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T4 T29 T30
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T4 T29 T30
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T4 T29 T30
135 1/1 txn_bits_q <= '0;
Tests: T4 T29 T30
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_key_invert_ctl_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T4,T29,T30 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T4,T29,T30 |
1 | 1 | Covered | T4,T29,T30 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T4,T29,T30 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T4,T29,T30 |
1 | 1 | Covered | T4,T29,T30 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_key_invert_ctl_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T4,T29,T30 |
0 |
0 |
1 |
Covered |
T4,T29,T30 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T4,T29,T30 |
0 |
0 |
1 |
Covered |
T4,T29,T30 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_key_invert_ctl_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1982125 |
0 |
0 |
T1 |
114854 |
0 |
0 |
0 |
T4 |
54651 |
7702 |
0 |
0 |
T5 |
65907 |
0 |
0 |
0 |
T6 |
56928 |
0 |
0 |
0 |
T14 |
51486 |
0 |
0 |
0 |
T15 |
245841 |
0 |
0 |
0 |
T16 |
194595 |
0 |
0 |
0 |
T17 |
32200 |
0 |
0 |
0 |
T18 |
50958 |
0 |
0 |
0 |
T23 |
45481 |
0 |
0 |
0 |
T29 |
0 |
15755 |
0 |
0 |
T30 |
0 |
8881 |
0 |
0 |
T54 |
0 |
8498 |
0 |
0 |
T67 |
0 |
15060 |
0 |
0 |
T84 |
0 |
3060 |
0 |
0 |
T85 |
0 |
34082 |
0 |
0 |
T86 |
0 |
9004 |
0 |
0 |
T87 |
0 |
15454 |
0 |
0 |
T88 |
0 |
8414 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
2212 |
0 |
0 |
T1 |
114854 |
0 |
0 |
0 |
T4 |
54651 |
20 |
0 |
0 |
T5 |
65907 |
0 |
0 |
0 |
T6 |
56928 |
0 |
0 |
0 |
T14 |
51486 |
0 |
0 |
0 |
T15 |
245841 |
0 |
0 |
0 |
T16 |
194595 |
0 |
0 |
0 |
T17 |
32200 |
0 |
0 |
0 |
T18 |
50958 |
0 |
0 |
0 |
T23 |
45481 |
0 |
0 |
0 |
T29 |
0 |
20 |
0 |
0 |
T30 |
0 |
20 |
0 |
0 |
T54 |
0 |
20 |
0 |
0 |
T67 |
0 |
20 |
0 |
0 |
T84 |
0 |
20 |
0 |
0 |
T85 |
0 |
20 |
0 |
0 |
T86 |
0 |
20 |
0 |
0 |
T87 |
0 |
20 |
0 |
0 |
T88 |
0 |
20 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_pin_allowed_ctl_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T4 T15 T20
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T4 T15 T20
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T4 T15 T20
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T4 T15 T20
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T4 T15 T20
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T4 T15 T20
135 1/1 txn_bits_q <= '0;
Tests: T4 T15 T20
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_pin_allowed_ctl_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T4,T15,T20 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T4,T15,T20 |
1 | 1 | Covered | T4,T15,T20 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T4,T15,T20 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T4,T15,T20 |
1 | 1 | Covered | T4,T15,T20 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_pin_allowed_ctl_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T4,T15,T20 |
0 |
0 |
1 |
Covered |
T4,T15,T20 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T4,T15,T20 |
0 |
0 |
1 |
Covered |
T4,T15,T20 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_pin_allowed_ctl_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
3554614 |
0 |
0 |
T1 |
114854 |
0 |
0 |
0 |
T4 |
54651 |
430 |
0 |
0 |
T5 |
65907 |
0 |
0 |
0 |
T6 |
56928 |
0 |
0 |
0 |
T14 |
51486 |
0 |
0 |
0 |
T15 |
245841 |
33419 |
0 |
0 |
T16 |
194595 |
0 |
0 |
0 |
T17 |
32200 |
0 |
0 |
0 |
T18 |
50958 |
0 |
0 |
0 |
T20 |
0 |
34428 |
0 |
0 |
T22 |
0 |
7642 |
0 |
0 |
T23 |
45481 |
0 |
0 |
0 |
T28 |
0 |
5283 |
0 |
0 |
T29 |
0 |
666 |
0 |
0 |
T30 |
0 |
498 |
0 |
0 |
T81 |
0 |
16615 |
0 |
0 |
T89 |
0 |
3888 |
0 |
0 |
T90 |
0 |
17856 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
3948 |
0 |
0 |
T1 |
114854 |
0 |
0 |
0 |
T4 |
54651 |
1 |
0 |
0 |
T5 |
65907 |
0 |
0 |
0 |
T6 |
56928 |
0 |
0 |
0 |
T14 |
51486 |
0 |
0 |
0 |
T15 |
245841 |
20 |
0 |
0 |
T16 |
194595 |
0 |
0 |
0 |
T17 |
32200 |
0 |
0 |
0 |
T18 |
50958 |
0 |
0 |
0 |
T20 |
0 |
20 |
0 |
0 |
T22 |
0 |
20 |
0 |
0 |
T23 |
45481 |
0 |
0 |
0 |
T28 |
0 |
20 |
0 |
0 |
T29 |
0 |
1 |
0 |
0 |
T30 |
0 |
1 |
0 |
0 |
T81 |
0 |
20 |
0 |
0 |
T89 |
0 |
20 |
0 |
0 |
T90 |
0 |
20 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_pin_out_ctl_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T4 T6 T1
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T4 T6 T1
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T4 T6 T1
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T4 T6 T1
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T4 T6 T1
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T4 T6 T1
135 1/1 txn_bits_q <= '0;
Tests: T4 T6 T1
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_pin_out_ctl_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T4,T6,T1 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T4,T6,T1 |
1 | 1 | Covered | T4,T6,T1 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T4,T6,T1 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T4,T6,T1 |
1 | 1 | Covered | T4,T6,T1 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_pin_out_ctl_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T4,T6,T1 |
0 |
0 |
1 |
Covered |
T4,T6,T1 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T4,T6,T1 |
0 |
0 |
1 |
Covered |
T4,T6,T1 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_pin_out_ctl_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
4573170 |
0 |
0 |
T1 |
114854 |
937 |
0 |
0 |
T4 |
54651 |
435 |
0 |
0 |
T5 |
65907 |
0 |
0 |
0 |
T6 |
56928 |
480 |
0 |
0 |
T14 |
51486 |
260 |
0 |
0 |
T15 |
245841 |
33703 |
0 |
0 |
T16 |
194595 |
0 |
0 |
0 |
T17 |
32200 |
0 |
0 |
0 |
T18 |
50958 |
0 |
0 |
0 |
T19 |
0 |
1436 |
0 |
0 |
T20 |
0 |
34508 |
0 |
0 |
T21 |
0 |
745 |
0 |
0 |
T22 |
0 |
7905 |
0 |
0 |
T23 |
45481 |
0 |
0 |
0 |
T65 |
0 |
240 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
5031 |
0 |
0 |
T1 |
114854 |
1 |
0 |
0 |
T4 |
54651 |
1 |
0 |
0 |
T5 |
65907 |
0 |
0 |
0 |
T6 |
56928 |
1 |
0 |
0 |
T14 |
51486 |
1 |
0 |
0 |
T15 |
245841 |
20 |
0 |
0 |
T16 |
194595 |
0 |
0 |
0 |
T17 |
32200 |
0 |
0 |
0 |
T18 |
50958 |
0 |
0 |
0 |
T19 |
0 |
1 |
0 |
0 |
T20 |
0 |
20 |
0 |
0 |
T21 |
0 |
1 |
0 |
0 |
T22 |
0 |
20 |
0 |
0 |
T23 |
45481 |
0 |
0 |
0 |
T65 |
0 |
1 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_pin_out_value_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T15 T20 T22
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T15 T20 T22
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T15 T20 T22
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T15 T20 T22
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T15 T20 T22
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T15 T20 T22
135 1/1 txn_bits_q <= '0;
Tests: T15 T20 T22
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_pin_out_value_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T15,T20,T22 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T15,T20,T22 |
1 | 1 | Covered | T15,T20,T22 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T15,T20,T22 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T15,T20,T22 |
1 | 1 | Covered | T15,T20,T22 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_pin_out_value_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T15,T20,T22 |
0 |
0 |
1 |
Covered |
T15,T20,T22 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T15,T20,T22 |
0 |
0 |
1 |
Covered |
T15,T20,T22 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_pin_out_value_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
3576138 |
0 |
0 |
T8 |
0 |
5972 |
0 |
0 |
T15 |
245841 |
33562 |
0 |
0 |
T16 |
194595 |
0 |
0 |
0 |
T17 |
32200 |
0 |
0 |
0 |
T18 |
50958 |
0 |
0 |
0 |
T19 |
211306 |
0 |
0 |
0 |
T20 |
261056 |
34468 |
0 |
0 |
T21 |
111144 |
0 |
0 |
0 |
T22 |
63048 |
7769 |
0 |
0 |
T28 |
0 |
5323 |
0 |
0 |
T29 |
113251 |
0 |
0 |
0 |
T65 |
35463 |
0 |
0 |
0 |
T68 |
0 |
7067 |
0 |
0 |
T75 |
0 |
8247 |
0 |
0 |
T81 |
0 |
16655 |
0 |
0 |
T89 |
0 |
3928 |
0 |
0 |
T90 |
0 |
18009 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
3939 |
0 |
0 |
T8 |
0 |
20 |
0 |
0 |
T15 |
245841 |
20 |
0 |
0 |
T16 |
194595 |
0 |
0 |
0 |
T17 |
32200 |
0 |
0 |
0 |
T18 |
50958 |
0 |
0 |
0 |
T19 |
211306 |
0 |
0 |
0 |
T20 |
261056 |
20 |
0 |
0 |
T21 |
111144 |
0 |
0 |
0 |
T22 |
63048 |
20 |
0 |
0 |
T28 |
0 |
20 |
0 |
0 |
T29 |
113251 |
0 |
0 |
0 |
T65 |
35463 |
0 |
0 |
0 |
T68 |
0 |
20 |
0 |
0 |
T75 |
0 |
20 |
0 |
0 |
T81 |
0 |
20 |
0 |
0 |
T89 |
0 |
20 |
0 |
0 |
T90 |
0 |
20 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_key_intr_ctl_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T3 T7 T12
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T3 T7 T12
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T3 T7 T12
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T3 T7 T12
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T3 T7 T12
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T3 T7 T12
135 1/1 txn_bits_q <= '0;
Tests: T3 T7 T12
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_key_intr_ctl_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T3,T7,T12 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T3,T7,T12 |
1 | 1 | Covered | T3,T7,T12 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T3,T7,T12 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T3,T7,T12 |
1 | 1 | Covered | T3,T7,T12 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_key_intr_ctl_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T3,T7,T12 |
0 |
0 |
1 |
Covered |
T3,T7,T12 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T3,T7,T12 |
0 |
0 |
1 |
Covered |
T3,T7,T12 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_key_intr_ctl_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
974924 |
0 |
0 |
T3 |
374218 |
1430 |
0 |
0 |
T7 |
0 |
116 |
0 |
0 |
T9 |
15197 |
0 |
0 |
0 |
T12 |
0 |
270 |
0 |
0 |
T30 |
62131 |
0 |
0 |
0 |
T33 |
47086 |
0 |
0 |
0 |
T35 |
0 |
13413 |
0 |
0 |
T48 |
0 |
1932 |
0 |
0 |
T50 |
0 |
499 |
0 |
0 |
T52 |
0 |
1396 |
0 |
0 |
T53 |
0 |
472 |
0 |
0 |
T54 |
0 |
481 |
0 |
0 |
T55 |
0 |
108 |
0 |
0 |
T80 |
196791 |
0 |
0 |
0 |
T81 |
118182 |
0 |
0 |
0 |
T82 |
337286 |
0 |
0 |
0 |
T83 |
54981 |
0 |
0 |
0 |
T89 |
28057 |
0 |
0 |
0 |
T91 |
98953 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
996 |
0 |
0 |
T3 |
374218 |
1 |
0 |
0 |
T7 |
0 |
1 |
0 |
0 |
T9 |
15197 |
0 |
0 |
0 |
T12 |
0 |
2 |
0 |
0 |
T30 |
62131 |
0 |
0 |
0 |
T33 |
47086 |
0 |
0 |
0 |
T35 |
0 |
28 |
0 |
0 |
T48 |
0 |
1 |
0 |
0 |
T50 |
0 |
1 |
0 |
0 |
T52 |
0 |
1 |
0 |
0 |
T53 |
0 |
1 |
0 |
0 |
T54 |
0 |
1 |
0 |
0 |
T55 |
0 |
1 |
0 |
0 |
T80 |
196791 |
0 |
0 |
0 |
T81 |
118182 |
0 |
0 |
0 |
T82 |
337286 |
0 |
0 |
0 |
T83 |
54981 |
0 |
0 |
0 |
T89 |
28057 |
0 |
0 |
0 |
T91 |
98953 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_key_intr_debounce_ctl_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T6 T1 T19
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T6 T1 T19
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T6 T1 T19
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T6 T1 T19
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T6 T1 T19
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T6 T1 T19
135 1/1 txn_bits_q <= '0;
Tests: T6 T1 T19
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_key_intr_debounce_ctl_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T6,T1,T19 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T6,T1,T19 |
1 | 1 | Covered | T6,T1,T19 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T6,T1,T19 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T6,T1,T19 |
1 | 1 | Covered | T6,T1,T19 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_key_intr_debounce_ctl_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T6,T1,T19 |
0 |
0 |
1 |
Covered |
T6,T1,T19 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T6,T1,T19 |
0 |
0 |
1 |
Covered |
T6,T1,T19 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_key_intr_debounce_ctl_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1705745 |
0 |
0 |
T1 |
114854 |
882 |
0 |
0 |
T2 |
0 |
433 |
0 |
0 |
T3 |
0 |
1425 |
0 |
0 |
T6 |
56928 |
427 |
0 |
0 |
T7 |
0 |
114 |
0 |
0 |
T9 |
0 |
65 |
0 |
0 |
T14 |
51486 |
0 |
0 |
0 |
T15 |
245841 |
0 |
0 |
0 |
T16 |
194595 |
0 |
0 |
0 |
T17 |
32200 |
0 |
0 |
0 |
T18 |
50958 |
0 |
0 |
0 |
T19 |
211306 |
1426 |
0 |
0 |
T20 |
261056 |
0 |
0 |
0 |
T21 |
0 |
679 |
0 |
0 |
T23 |
45481 |
0 |
0 |
0 |
T33 |
0 |
339 |
0 |
0 |
T34 |
0 |
288 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1873 |
0 |
0 |
T1 |
114854 |
1 |
0 |
0 |
T2 |
0 |
1 |
0 |
0 |
T3 |
0 |
1 |
0 |
0 |
T6 |
56928 |
1 |
0 |
0 |
T7 |
0 |
1 |
0 |
0 |
T9 |
0 |
1 |
0 |
0 |
T14 |
51486 |
0 |
0 |
0 |
T15 |
245841 |
0 |
0 |
0 |
T16 |
194595 |
0 |
0 |
0 |
T17 |
32200 |
0 |
0 |
0 |
T18 |
50958 |
0 |
0 |
0 |
T19 |
211306 |
1 |
0 |
0 |
T20 |
261056 |
0 |
0 |
0 |
T21 |
0 |
1 |
0 |
0 |
T23 |
45481 |
0 |
0 |
0 |
T33 |
0 |
1 |
0 |
0 |
T34 |
0 |
1 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_auto_block_debounce_ctl_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T16 T31 T32
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T16 T31 T32
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T16 T31 T32
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T16 T31 T32
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T16 T31 T32
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T16 T31 T32
135 1/1 txn_bits_q <= '0;
Tests: T16 T31 T32
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_auto_block_debounce_ctl_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T16,T31,T32 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T16,T31,T32 |
1 | 1 | Covered | T16,T31,T32 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T16,T31,T32 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T16,T31,T32 |
1 | 1 | Covered | T16,T31,T32 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_auto_block_debounce_ctl_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T16,T31,T32 |
0 |
0 |
1 |
Covered |
T16,T31,T32 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T16,T31,T32 |
0 |
0 |
1 |
Covered |
T16,T31,T32 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_auto_block_debounce_ctl_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1094757 |
0 |
0 |
T16 |
194595 |
3478 |
0 |
0 |
T17 |
32200 |
0 |
0 |
0 |
T18 |
50958 |
0 |
0 |
0 |
T19 |
211306 |
0 |
0 |
0 |
T20 |
261056 |
0 |
0 |
0 |
T21 |
111144 |
0 |
0 |
0 |
T22 |
63048 |
0 |
0 |
0 |
T28 |
175637 |
0 |
0 |
0 |
T29 |
113251 |
0 |
0 |
0 |
T31 |
0 |
1948 |
0 |
0 |
T32 |
0 |
6772 |
0 |
0 |
T35 |
0 |
840 |
0 |
0 |
T54 |
0 |
1853 |
0 |
0 |
T60 |
0 |
4099 |
0 |
0 |
T61 |
0 |
2135 |
0 |
0 |
T62 |
0 |
5202 |
0 |
0 |
T63 |
0 |
2348 |
0 |
0 |
T64 |
0 |
2273 |
0 |
0 |
T65 |
35463 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1165 |
0 |
0 |
T16 |
194595 |
4 |
0 |
0 |
T17 |
32200 |
0 |
0 |
0 |
T18 |
50958 |
0 |
0 |
0 |
T19 |
211306 |
0 |
0 |
0 |
T20 |
261056 |
0 |
0 |
0 |
T21 |
111144 |
0 |
0 |
0 |
T22 |
63048 |
0 |
0 |
0 |
T28 |
175637 |
0 |
0 |
0 |
T29 |
113251 |
0 |
0 |
0 |
T31 |
0 |
5 |
0 |
0 |
T32 |
0 |
4 |
0 |
0 |
T35 |
0 |
2 |
0 |
0 |
T54 |
0 |
4 |
0 |
0 |
T60 |
0 |
5 |
0 |
0 |
T61 |
0 |
5 |
0 |
0 |
T62 |
0 |
3 |
0 |
0 |
T63 |
0 |
5 |
0 |
0 |
T64 |
0 |
5 |
0 |
0 |
T65 |
35463 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_auto_block_out_ctl_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T16 T31 T32
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T16 T31 T32
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T16 T31 T32
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T16 T31 T32
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T16 T31 T32
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T16 T31 T32
135 1/1 txn_bits_q <= '0;
Tests: T16 T31 T32
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_auto_block_out_ctl_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T16,T31,T32 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T16,T31,T32 |
1 | 1 | Covered | T16,T31,T32 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T16,T31,T32 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T16,T31,T32 |
1 | 1 | Covered | T16,T31,T32 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_auto_block_out_ctl_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T16,T31,T32 |
0 |
0 |
1 |
Covered |
T16,T31,T32 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T16,T31,T32 |
0 |
0 |
1 |
Covered |
T16,T31,T32 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_auto_block_out_ctl_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1018203 |
0 |
0 |
T16 |
194595 |
2704 |
0 |
0 |
T17 |
32200 |
0 |
0 |
0 |
T18 |
50958 |
0 |
0 |
0 |
T19 |
211306 |
0 |
0 |
0 |
T20 |
261056 |
0 |
0 |
0 |
T21 |
111144 |
0 |
0 |
0 |
T22 |
63048 |
0 |
0 |
0 |
T28 |
175637 |
0 |
0 |
0 |
T29 |
113251 |
0 |
0 |
0 |
T31 |
0 |
1256 |
0 |
0 |
T32 |
0 |
4811 |
0 |
0 |
T35 |
0 |
417 |
0 |
0 |
T54 |
0 |
1355 |
0 |
0 |
T60 |
0 |
2445 |
0 |
0 |
T61 |
0 |
1274 |
0 |
0 |
T62 |
0 |
5190 |
0 |
0 |
T63 |
0 |
1330 |
0 |
0 |
T64 |
0 |
1460 |
0 |
0 |
T65 |
35463 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1055 |
0 |
0 |
T16 |
194595 |
3 |
0 |
0 |
T17 |
32200 |
0 |
0 |
0 |
T18 |
50958 |
0 |
0 |
0 |
T19 |
211306 |
0 |
0 |
0 |
T20 |
261056 |
0 |
0 |
0 |
T21 |
111144 |
0 |
0 |
0 |
T22 |
63048 |
0 |
0 |
0 |
T28 |
175637 |
0 |
0 |
0 |
T29 |
113251 |
0 |
0 |
0 |
T31 |
0 |
3 |
0 |
0 |
T32 |
0 |
3 |
0 |
0 |
T35 |
0 |
1 |
0 |
0 |
T54 |
0 |
3 |
0 |
0 |
T60 |
0 |
3 |
0 |
0 |
T61 |
0 |
3 |
0 |
0 |
T62 |
0 |
3 |
0 |
0 |
T63 |
0 |
3 |
0 |
0 |
T64 |
0 |
3 |
0 |
0 |
T65 |
35463 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_com_pre_sel_ctl_0_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T6 T2 T33
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T6 T2 T33
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T6 T2 T33
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T6 T2 T33
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T6 T2 T33
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T6 T2 T33
135 1/1 txn_bits_q <= '0;
Tests: T6 T2 T33
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_com_pre_sel_ctl_0_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T6,T2,T33 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T6,T2,T33 |
1 | 1 | Covered | T6,T2,T33 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T6,T2,T33 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T6,T2,T33 |
1 | 1 | Covered | T6,T2,T33 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_com_pre_sel_ctl_0_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T6,T2,T33 |
0 |
0 |
1 |
Covered |
T6,T2,T33 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T6,T2,T33 |
0 |
0 |
1 |
Covered |
T6,T2,T33 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_com_pre_sel_ctl_0_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
6702078 |
0 |
0 |
T1 |
114854 |
0 |
0 |
0 |
T2 |
0 |
490 |
0 |
0 |
T6 |
56928 |
498 |
0 |
0 |
T14 |
51486 |
0 |
0 |
0 |
T15 |
245841 |
0 |
0 |
0 |
T16 |
194595 |
0 |
0 |
0 |
T17 |
32200 |
0 |
0 |
0 |
T18 |
50958 |
0 |
0 |
0 |
T19 |
211306 |
0 |
0 |
0 |
T20 |
261056 |
0 |
0 |
0 |
T23 |
45481 |
0 |
0 |
0 |
T33 |
0 |
393 |
0 |
0 |
T34 |
0 |
19017 |
0 |
0 |
T35 |
0 |
4893 |
0 |
0 |
T36 |
0 |
33785 |
0 |
0 |
T59 |
0 |
31229 |
0 |
0 |
T92 |
0 |
1422 |
0 |
0 |
T93 |
0 |
1900 |
0 |
0 |
T94 |
0 |
111194 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
7366 |
0 |
0 |
T1 |
114854 |
0 |
0 |
0 |
T2 |
0 |
1 |
0 |
0 |
T6 |
56928 |
1 |
0 |
0 |
T14 |
51486 |
0 |
0 |
0 |
T15 |
245841 |
0 |
0 |
0 |
T16 |
194595 |
0 |
0 |
0 |
T17 |
32200 |
0 |
0 |
0 |
T18 |
50958 |
0 |
0 |
0 |
T19 |
211306 |
0 |
0 |
0 |
T20 |
261056 |
0 |
0 |
0 |
T23 |
45481 |
0 |
0 |
0 |
T33 |
0 |
1 |
0 |
0 |
T34 |
0 |
51 |
0 |
0 |
T35 |
0 |
11 |
0 |
0 |
T36 |
0 |
82 |
0 |
0 |
T59 |
0 |
75 |
0 |
0 |
T92 |
0 |
1 |
0 |
0 |
T93 |
0 |
1 |
0 |
0 |
T94 |
0 |
64 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_com_pre_sel_ctl_1_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T34 T35 T36
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T34 T35 T36
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T34 T35 T36
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T34 T35 T36
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T34 T35 T36
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T34 T35 T36
135 1/1 txn_bits_q <= '0;
Tests: T34 T35 T36
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_com_pre_sel_ctl_1_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_com_pre_sel_ctl_1_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_com_pre_sel_ctl_1_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
6583518 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
29332 |
0 |
0 |
T35 |
0 |
4910 |
0 |
0 |
T36 |
0 |
26091 |
0 |
0 |
T58 |
0 |
17669 |
0 |
0 |
T59 |
0 |
29680 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T69 |
0 |
20355 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
92756 |
0 |
0 |
T95 |
0 |
20202 |
0 |
0 |
T96 |
0 |
19296 |
0 |
0 |
T97 |
0 |
21196 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
7349 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
79 |
0 |
0 |
T35 |
0 |
11 |
0 |
0 |
T36 |
0 |
67 |
0 |
0 |
T58 |
0 |
54 |
0 |
0 |
T59 |
0 |
72 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T69 |
0 |
11 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
54 |
0 |
0 |
T95 |
0 |
54 |
0 |
0 |
T96 |
0 |
51 |
0 |
0 |
T97 |
0 |
51 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_com_pre_sel_ctl_2_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T34 T35 T36
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T34 T35 T36
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T34 T35 T36
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T34 T35 T36
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T34 T35 T36
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T34 T35 T36
135 1/1 txn_bits_q <= '0;
Tests: T34 T35 T36
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_com_pre_sel_ctl_2_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_com_pre_sel_ctl_2_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_com_pre_sel_ctl_2_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
6403774 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
29010 |
0 |
0 |
T35 |
0 |
4929 |
0 |
0 |
T36 |
0 |
32240 |
0 |
0 |
T58 |
0 |
23494 |
0 |
0 |
T59 |
0 |
30290 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T69 |
0 |
20355 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
116969 |
0 |
0 |
T95 |
0 |
19457 |
0 |
0 |
T96 |
0 |
18178 |
0 |
0 |
T97 |
0 |
20986 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
7175 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
79 |
0 |
0 |
T35 |
0 |
11 |
0 |
0 |
T36 |
0 |
83 |
0 |
0 |
T58 |
0 |
75 |
0 |
0 |
T59 |
0 |
74 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T69 |
0 |
11 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
68 |
0 |
0 |
T95 |
0 |
54 |
0 |
0 |
T96 |
0 |
51 |
0 |
0 |
T97 |
0 |
51 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_com_pre_sel_ctl_3_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T34 T35 T36
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T34 T35 T36
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T34 T35 T36
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T34 T35 T36
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T34 T35 T36
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T34 T35 T36
135 1/1 txn_bits_q <= '0;
Tests: T34 T35 T36
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_com_pre_sel_ctl_3_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_com_pre_sel_ctl_3_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_com_pre_sel_ctl_3_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
6453147 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
25415 |
0 |
0 |
T35 |
0 |
4901 |
0 |
0 |
T36 |
0 |
23426 |
0 |
0 |
T58 |
0 |
22893 |
0 |
0 |
T59 |
0 |
27718 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T69 |
0 |
20355 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
116691 |
0 |
0 |
T95 |
0 |
18784 |
0 |
0 |
T96 |
0 |
17208 |
0 |
0 |
T97 |
0 |
20776 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
7251 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
70 |
0 |
0 |
T35 |
0 |
11 |
0 |
0 |
T36 |
0 |
63 |
0 |
0 |
T58 |
0 |
75 |
0 |
0 |
T59 |
0 |
68 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T69 |
0 |
11 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
68 |
0 |
0 |
T95 |
0 |
54 |
0 |
0 |
T96 |
0 |
51 |
0 |
0 |
T97 |
0 |
51 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_com_pre_det_ctl_0_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T6 T2 T33
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T6 T2 T33
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T6 T2 T33
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T6 T2 T33
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T6 T2 T33
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T6 T2 T33
135 1/1 txn_bits_q <= '0;
Tests: T6 T2 T33
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_com_pre_det_ctl_0_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T6,T2,T33 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T6,T2,T33 |
1 | 1 | Covered | T6,T2,T33 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T6,T2,T33 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T6,T2,T33 |
1 | 1 | Covered | T6,T2,T33 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_com_pre_det_ctl_0_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T6,T2,T33 |
0 |
0 |
1 |
Covered |
T6,T2,T33 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T6,T2,T33 |
0 |
0 |
1 |
Covered |
T6,T2,T33 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_com_pre_det_ctl_0_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1209889 |
0 |
0 |
T1 |
114854 |
0 |
0 |
0 |
T2 |
0 |
480 |
0 |
0 |
T6 |
56928 |
492 |
0 |
0 |
T14 |
51486 |
0 |
0 |
0 |
T15 |
245841 |
0 |
0 |
0 |
T16 |
194595 |
0 |
0 |
0 |
T17 |
32200 |
0 |
0 |
0 |
T18 |
50958 |
0 |
0 |
0 |
T19 |
211306 |
0 |
0 |
0 |
T20 |
261056 |
0 |
0 |
0 |
T23 |
45481 |
0 |
0 |
0 |
T33 |
0 |
382 |
0 |
0 |
T34 |
0 |
328 |
0 |
0 |
T35 |
0 |
3859 |
0 |
0 |
T36 |
0 |
686 |
0 |
0 |
T59 |
0 |
479 |
0 |
0 |
T92 |
0 |
1418 |
0 |
0 |
T93 |
0 |
1898 |
0 |
0 |
T94 |
0 |
1919 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1263 |
0 |
0 |
T1 |
114854 |
0 |
0 |
0 |
T2 |
0 |
1 |
0 |
0 |
T6 |
56928 |
1 |
0 |
0 |
T14 |
51486 |
0 |
0 |
0 |
T15 |
245841 |
0 |
0 |
0 |
T16 |
194595 |
0 |
0 |
0 |
T17 |
32200 |
0 |
0 |
0 |
T18 |
50958 |
0 |
0 |
0 |
T19 |
211306 |
0 |
0 |
0 |
T20 |
261056 |
0 |
0 |
0 |
T23 |
45481 |
0 |
0 |
0 |
T33 |
0 |
1 |
0 |
0 |
T34 |
0 |
1 |
0 |
0 |
T35 |
0 |
9 |
0 |
0 |
T36 |
0 |
2 |
0 |
0 |
T59 |
0 |
1 |
0 |
0 |
T92 |
0 |
1 |
0 |
0 |
T93 |
0 |
1 |
0 |
0 |
T94 |
0 |
1 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_com_pre_det_ctl_1_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T34 T35 T36
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T34 T35 T36
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T34 T35 T36
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T34 T35 T36
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T34 T35 T36
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T34 T35 T36
135 1/1 txn_bits_q <= '0;
Tests: T34 T35 T36
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_com_pre_det_ctl_1_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_com_pre_det_ctl_1_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_com_pre_det_ctl_1_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1237502 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
318 |
0 |
0 |
T35 |
0 |
3868 |
0 |
0 |
T36 |
0 |
610 |
0 |
0 |
T58 |
0 |
1204 |
0 |
0 |
T59 |
0 |
469 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T69 |
0 |
16455 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
1909 |
0 |
0 |
T95 |
0 |
280 |
0 |
0 |
T96 |
0 |
303 |
0 |
0 |
T97 |
0 |
469 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1292 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
1 |
0 |
0 |
T35 |
0 |
9 |
0 |
0 |
T36 |
0 |
2 |
0 |
0 |
T58 |
0 |
4 |
0 |
0 |
T59 |
0 |
1 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T69 |
0 |
9 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
1 |
0 |
0 |
T95 |
0 |
1 |
0 |
0 |
T96 |
0 |
1 |
0 |
0 |
T97 |
0 |
1 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_com_pre_det_ctl_2_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T34 T35 T36
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T34 T35 T36
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T34 T35 T36
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T34 T35 T36
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T34 T35 T36
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T34 T35 T36
135 1/1 txn_bits_q <= '0;
Tests: T34 T35 T36
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_com_pre_det_ctl_2_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_com_pre_det_ctl_2_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_com_pre_det_ctl_2_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1287080 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
308 |
0 |
0 |
T35 |
0 |
3906 |
0 |
0 |
T36 |
0 |
533 |
0 |
0 |
T58 |
0 |
1084 |
0 |
0 |
T59 |
0 |
459 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T69 |
0 |
16455 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
1899 |
0 |
0 |
T95 |
0 |
248 |
0 |
0 |
T96 |
0 |
249 |
0 |
0 |
T97 |
0 |
459 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1318 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
1 |
0 |
0 |
T35 |
0 |
9 |
0 |
0 |
T36 |
0 |
2 |
0 |
0 |
T58 |
0 |
4 |
0 |
0 |
T59 |
0 |
1 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T69 |
0 |
9 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
1 |
0 |
0 |
T95 |
0 |
1 |
0 |
0 |
T96 |
0 |
1 |
0 |
0 |
T97 |
0 |
1 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_com_pre_det_ctl_3_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T34 T35 T36
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T34 T35 T36
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T34 T35 T36
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T34 T35 T36
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T34 T35 T36
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T34 T35 T36
135 1/1 txn_bits_q <= '0;
Tests: T34 T35 T36
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_com_pre_det_ctl_3_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_com_pre_det_ctl_3_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_com_pre_det_ctl_3_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1222604 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
298 |
0 |
0 |
T35 |
0 |
3886 |
0 |
0 |
T36 |
0 |
587 |
0 |
0 |
T58 |
0 |
1334 |
0 |
0 |
T59 |
0 |
449 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T69 |
0 |
16455 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
1889 |
0 |
0 |
T95 |
0 |
319 |
0 |
0 |
T96 |
0 |
321 |
0 |
0 |
T97 |
0 |
449 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1296 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
1 |
0 |
0 |
T35 |
0 |
9 |
0 |
0 |
T36 |
0 |
2 |
0 |
0 |
T58 |
0 |
4 |
0 |
0 |
T59 |
0 |
1 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T69 |
0 |
9 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
1 |
0 |
0 |
T95 |
0 |
1 |
0 |
0 |
T96 |
0 |
1 |
0 |
0 |
T97 |
0 |
1 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_com_sel_ctl_0_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T6 T1 T19
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T6 T1 T19
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T6 T1 T19
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T6 T1 T19
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T6 T1 T19
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T6 T1 T19
135 1/1 txn_bits_q <= '0;
Tests: T6 T1 T19
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_com_sel_ctl_0_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T6,T1,T19 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T6,T1,T19 |
1 | 1 | Covered | T6,T1,T19 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T6,T1,T19 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T6,T1,T19 |
1 | 1 | Covered | T6,T1,T19 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_com_sel_ctl_0_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T6,T1,T19 |
0 |
0 |
1 |
Covered |
T6,T1,T19 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T6,T1,T19 |
0 |
0 |
1 |
Covered |
T6,T1,T19 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_com_sel_ctl_0_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
7215768 |
0 |
0 |
T1 |
114854 |
929 |
0 |
0 |
T2 |
0 |
452 |
0 |
0 |
T6 |
56928 |
471 |
0 |
0 |
T9 |
0 |
67 |
0 |
0 |
T10 |
0 |
335 |
0 |
0 |
T12 |
0 |
130 |
0 |
0 |
T14 |
51486 |
0 |
0 |
0 |
T15 |
245841 |
0 |
0 |
0 |
T16 |
194595 |
0 |
0 |
0 |
T17 |
32200 |
0 |
0 |
0 |
T18 |
50958 |
0 |
0 |
0 |
T19 |
211306 |
1434 |
0 |
0 |
T20 |
261056 |
0 |
0 |
0 |
T21 |
0 |
729 |
0 |
0 |
T23 |
45481 |
0 |
0 |
0 |
T33 |
0 |
368 |
0 |
0 |
T34 |
0 |
19113 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
7882 |
0 |
0 |
T1 |
114854 |
1 |
0 |
0 |
T2 |
0 |
1 |
0 |
0 |
T6 |
56928 |
1 |
0 |
0 |
T9 |
0 |
1 |
0 |
0 |
T10 |
0 |
1 |
0 |
0 |
T12 |
0 |
1 |
0 |
0 |
T14 |
51486 |
0 |
0 |
0 |
T15 |
245841 |
0 |
0 |
0 |
T16 |
194595 |
0 |
0 |
0 |
T17 |
32200 |
0 |
0 |
0 |
T18 |
50958 |
0 |
0 |
0 |
T19 |
211306 |
1 |
0 |
0 |
T20 |
261056 |
0 |
0 |
0 |
T21 |
0 |
1 |
0 |
0 |
T23 |
45481 |
0 |
0 |
0 |
T33 |
0 |
1 |
0 |
0 |
T34 |
0 |
51 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_com_sel_ctl_1_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T34 T35 T36
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T34 T35 T36
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T34 T35 T36
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T34 T35 T36
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T34 T35 T36
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T34 T35 T36
135 1/1 txn_bits_q <= '0;
Tests: T34 T35 T36
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_com_sel_ctl_1_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_com_sel_ctl_1_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_com_sel_ctl_1_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
7159395 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
29484 |
0 |
0 |
T35 |
0 |
4785 |
0 |
0 |
T36 |
0 |
26538 |
0 |
0 |
T37 |
0 |
361 |
0 |
0 |
T43 |
0 |
2673 |
0 |
0 |
T44 |
0 |
2762 |
0 |
0 |
T59 |
0 |
29818 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
92858 |
0 |
0 |
T95 |
0 |
20561 |
0 |
0 |
T96 |
0 |
19794 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
7916 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
79 |
0 |
0 |
T35 |
0 |
11 |
0 |
0 |
T36 |
0 |
67 |
0 |
0 |
T37 |
0 |
1 |
0 |
0 |
T43 |
0 |
7 |
0 |
0 |
T44 |
0 |
10 |
0 |
0 |
T59 |
0 |
72 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
54 |
0 |
0 |
T95 |
0 |
54 |
0 |
0 |
T96 |
0 |
51 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_com_sel_ctl_2_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T34 T35 T36
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T34 T35 T36
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T34 T35 T36
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T34 T35 T36
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T34 T35 T36
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T34 T35 T36
135 1/1 txn_bits_q <= '0;
Tests: T34 T35 T36
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_com_sel_ctl_2_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_com_sel_ctl_2_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_com_sel_ctl_2_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
6918857 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
29162 |
0 |
0 |
T35 |
0 |
4807 |
0 |
0 |
T36 |
0 |
32906 |
0 |
0 |
T37 |
0 |
354 |
0 |
0 |
T43 |
0 |
2618 |
0 |
0 |
T44 |
0 |
2742 |
0 |
0 |
T59 |
0 |
30432 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
117099 |
0 |
0 |
T95 |
0 |
19819 |
0 |
0 |
T96 |
0 |
18783 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
7692 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
79 |
0 |
0 |
T35 |
0 |
11 |
0 |
0 |
T36 |
0 |
83 |
0 |
0 |
T37 |
0 |
1 |
0 |
0 |
T43 |
0 |
7 |
0 |
0 |
T44 |
0 |
10 |
0 |
0 |
T59 |
0 |
74 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
68 |
0 |
0 |
T95 |
0 |
54 |
0 |
0 |
T96 |
0 |
51 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_com_sel_ctl_3_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T34 T35 T36
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T34 T35 T36
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T34 T35 T36
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T34 T35 T36
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T34 T35 T36
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T34 T35 T36
135 1/1 txn_bits_q <= '0;
Tests: T34 T35 T36
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_com_sel_ctl_3_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_com_sel_ctl_3_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_com_sel_ctl_3_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
6953531 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
25549 |
0 |
0 |
T35 |
0 |
4785 |
0 |
0 |
T36 |
0 |
23857 |
0 |
0 |
T37 |
0 |
348 |
0 |
0 |
T43 |
0 |
2568 |
0 |
0 |
T44 |
0 |
2722 |
0 |
0 |
T59 |
0 |
27848 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
116821 |
0 |
0 |
T95 |
0 |
19164 |
0 |
0 |
T96 |
0 |
17722 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
7748 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
70 |
0 |
0 |
T35 |
0 |
11 |
0 |
0 |
T36 |
0 |
63 |
0 |
0 |
T37 |
0 |
1 |
0 |
0 |
T43 |
0 |
7 |
0 |
0 |
T44 |
0 |
10 |
0 |
0 |
T59 |
0 |
68 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
68 |
0 |
0 |
T95 |
0 |
54 |
0 |
0 |
T96 |
0 |
51 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_com_det_ctl_0_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T6 T1 T19
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T6 T1 T19
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T6 T1 T19
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T6 T1 T19
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T6 T1 T19
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T6 T1 T19
135 1/1 txn_bits_q <= '0;
Tests: T6 T1 T19
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_com_det_ctl_0_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T6,T1,T19 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T6,T1,T19 |
1 | 1 | Covered | T6,T1,T19 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T6,T1,T19 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T6,T1,T19 |
1 | 1 | Covered | T6,T1,T19 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_com_det_ctl_0_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T6,T1,T19 |
0 |
0 |
1 |
Covered |
T6,T1,T19 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T6,T1,T19 |
0 |
0 |
1 |
Covered |
T6,T1,T19 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_com_det_ctl_0_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1734386 |
0 |
0 |
T1 |
114854 |
917 |
0 |
0 |
T2 |
0 |
449 |
0 |
0 |
T6 |
56928 |
459 |
0 |
0 |
T9 |
0 |
88 |
0 |
0 |
T10 |
0 |
328 |
0 |
0 |
T12 |
0 |
123 |
0 |
0 |
T14 |
51486 |
0 |
0 |
0 |
T15 |
245841 |
0 |
0 |
0 |
T16 |
194595 |
0 |
0 |
0 |
T17 |
32200 |
0 |
0 |
0 |
T18 |
50958 |
0 |
0 |
0 |
T19 |
211306 |
1432 |
0 |
0 |
T20 |
261056 |
0 |
0 |
0 |
T21 |
0 |
715 |
0 |
0 |
T23 |
45481 |
0 |
0 |
0 |
T33 |
0 |
356 |
0 |
0 |
T34 |
0 |
324 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1850 |
0 |
0 |
T1 |
114854 |
1 |
0 |
0 |
T2 |
0 |
1 |
0 |
0 |
T6 |
56928 |
1 |
0 |
0 |
T9 |
0 |
1 |
0 |
0 |
T10 |
0 |
1 |
0 |
0 |
T12 |
0 |
1 |
0 |
0 |
T14 |
51486 |
0 |
0 |
0 |
T15 |
245841 |
0 |
0 |
0 |
T16 |
194595 |
0 |
0 |
0 |
T17 |
32200 |
0 |
0 |
0 |
T18 |
50958 |
0 |
0 |
0 |
T19 |
211306 |
1 |
0 |
0 |
T20 |
261056 |
0 |
0 |
0 |
T21 |
0 |
1 |
0 |
0 |
T23 |
45481 |
0 |
0 |
0 |
T33 |
0 |
1 |
0 |
0 |
T34 |
0 |
1 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_com_det_ctl_1_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T34 T35 T36
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T34 T35 T36
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T34 T35 T36
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T34 T35 T36
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T34 T35 T36
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T34 T35 T36
135 1/1 txn_bits_q <= '0;
Tests: T34 T35 T36
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_com_det_ctl_1_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_com_det_ctl_1_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_com_det_ctl_1_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1661429 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
314 |
0 |
0 |
T35 |
0 |
3758 |
0 |
0 |
T36 |
0 |
573 |
0 |
0 |
T37 |
0 |
340 |
0 |
0 |
T43 |
0 |
2469 |
0 |
0 |
T44 |
0 |
2682 |
0 |
0 |
T59 |
0 |
465 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
1905 |
0 |
0 |
T95 |
0 |
267 |
0 |
0 |
T96 |
0 |
280 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1770 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
1 |
0 |
0 |
T35 |
0 |
9 |
0 |
0 |
T36 |
0 |
2 |
0 |
0 |
T37 |
0 |
1 |
0 |
0 |
T43 |
0 |
7 |
0 |
0 |
T44 |
0 |
10 |
0 |
0 |
T59 |
0 |
1 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
1 |
0 |
0 |
T95 |
0 |
1 |
0 |
0 |
T96 |
0 |
1 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_com_det_ctl_2_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T34 T35 T36
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T34 T35 T36
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T34 T35 T36
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T34 T35 T36
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T34 T35 T36
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T34 T35 T36
135 1/1 txn_bits_q <= '0;
Tests: T34 T35 T36
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_com_det_ctl_2_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_com_det_ctl_2_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_com_det_ctl_2_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1661255 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
304 |
0 |
0 |
T35 |
0 |
3781 |
0 |
0 |
T36 |
0 |
631 |
0 |
0 |
T37 |
0 |
338 |
0 |
0 |
T43 |
0 |
2426 |
0 |
0 |
T44 |
0 |
2662 |
0 |
0 |
T59 |
0 |
455 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
1895 |
0 |
0 |
T95 |
0 |
232 |
0 |
0 |
T96 |
0 |
345 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1777 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
1 |
0 |
0 |
T35 |
0 |
9 |
0 |
0 |
T36 |
0 |
2 |
0 |
0 |
T37 |
0 |
1 |
0 |
0 |
T43 |
0 |
7 |
0 |
0 |
T44 |
0 |
10 |
0 |
0 |
T59 |
0 |
1 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
1 |
0 |
0 |
T95 |
0 |
1 |
0 |
0 |
T96 |
0 |
1 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_com_det_ctl_3_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T34 T35 T36
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T34 T35 T36
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T34 T35 T36
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T34 T35 T36
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T34 T35 T36
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T34 T35 T36
135 1/1 txn_bits_q <= '0;
Tests: T34 T35 T36
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_com_det_ctl_3_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_com_det_ctl_3_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_com_det_ctl_3_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1671146 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
294 |
0 |
0 |
T35 |
0 |
3756 |
0 |
0 |
T36 |
0 |
686 |
0 |
0 |
T37 |
0 |
335 |
0 |
0 |
T43 |
0 |
2370 |
0 |
0 |
T44 |
0 |
2642 |
0 |
0 |
T59 |
0 |
445 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
1885 |
0 |
0 |
T95 |
0 |
310 |
0 |
0 |
T96 |
0 |
289 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1807 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
1 |
0 |
0 |
T35 |
0 |
9 |
0 |
0 |
T36 |
0 |
2 |
0 |
0 |
T37 |
0 |
1 |
0 |
0 |
T43 |
0 |
7 |
0 |
0 |
T44 |
0 |
10 |
0 |
0 |
T59 |
0 |
1 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
1 |
0 |
0 |
T95 |
0 |
1 |
0 |
0 |
T96 |
0 |
1 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_com_out_ctl_0_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T6 T1 T19
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T6 T1 T19
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T6 T1 T19
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T6 T1 T19
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T6 T1 T19
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T6 T1 T19
135 1/1 txn_bits_q <= '0;
Tests: T6 T1 T19
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_com_out_ctl_0_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T6,T1,T19 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T6,T1,T19 |
1 | 1 | Covered | T6,T1,T19 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T6,T1,T19 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T6,T1,T19 |
1 | 1 | Covered | T6,T1,T19 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_com_out_ctl_0_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T6,T1,T19 |
0 |
0 |
1 |
Covered |
T6,T1,T19 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T6,T1,T19 |
0 |
0 |
1 |
Covered |
T6,T1,T19 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_com_out_ctl_0_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1727005 |
0 |
0 |
T1 |
114854 |
906 |
0 |
0 |
T2 |
0 |
446 |
0 |
0 |
T6 |
56928 |
447 |
0 |
0 |
T9 |
0 |
82 |
0 |
0 |
T10 |
0 |
324 |
0 |
0 |
T12 |
0 |
111 |
0 |
0 |
T14 |
51486 |
0 |
0 |
0 |
T15 |
245841 |
0 |
0 |
0 |
T16 |
194595 |
0 |
0 |
0 |
T17 |
32200 |
0 |
0 |
0 |
T18 |
50958 |
0 |
0 |
0 |
T19 |
211306 |
1430 |
0 |
0 |
T20 |
261056 |
0 |
0 |
0 |
T21 |
0 |
702 |
0 |
0 |
T23 |
45481 |
0 |
0 |
0 |
T33 |
0 |
348 |
0 |
0 |
T34 |
0 |
322 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1838 |
0 |
0 |
T1 |
114854 |
1 |
0 |
0 |
T2 |
0 |
1 |
0 |
0 |
T6 |
56928 |
1 |
0 |
0 |
T9 |
0 |
1 |
0 |
0 |
T10 |
0 |
1 |
0 |
0 |
T12 |
0 |
1 |
0 |
0 |
T14 |
51486 |
0 |
0 |
0 |
T15 |
245841 |
0 |
0 |
0 |
T16 |
194595 |
0 |
0 |
0 |
T17 |
32200 |
0 |
0 |
0 |
T18 |
50958 |
0 |
0 |
0 |
T19 |
211306 |
1 |
0 |
0 |
T20 |
261056 |
0 |
0 |
0 |
T21 |
0 |
1 |
0 |
0 |
T23 |
45481 |
0 |
0 |
0 |
T33 |
0 |
1 |
0 |
0 |
T34 |
0 |
1 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_com_out_ctl_1_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T34 T35 T36
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T34 T35 T36
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T34 T35 T36
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T34 T35 T36
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T34 T35 T36
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T34 T35 T36
135 1/1 txn_bits_q <= '0;
Tests: T34 T35 T36
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_com_out_ctl_1_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_com_out_ctl_1_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_com_out_ctl_1_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1699648 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
312 |
0 |
0 |
T35 |
0 |
3705 |
0 |
0 |
T36 |
0 |
566 |
0 |
0 |
T37 |
0 |
327 |
0 |
0 |
T43 |
0 |
2288 |
0 |
0 |
T44 |
0 |
2602 |
0 |
0 |
T59 |
0 |
463 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
1903 |
0 |
0 |
T95 |
0 |
264 |
0 |
0 |
T96 |
0 |
268 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1805 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
1 |
0 |
0 |
T35 |
0 |
9 |
0 |
0 |
T36 |
0 |
2 |
0 |
0 |
T37 |
0 |
1 |
0 |
0 |
T43 |
0 |
7 |
0 |
0 |
T44 |
0 |
10 |
0 |
0 |
T59 |
0 |
1 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
1 |
0 |
0 |
T95 |
0 |
1 |
0 |
0 |
T96 |
0 |
1 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_com_out_ctl_2_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T34 T35 T36
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T34 T35 T36
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T34 T35 T36
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T34 T35 T36
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T34 T35 T36
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T34 T35 T36
135 1/1 txn_bits_q <= '0;
Tests: T34 T35 T36
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_com_out_ctl_2_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_com_out_ctl_2_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_com_out_ctl_2_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1696275 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
302 |
0 |
0 |
T35 |
0 |
3714 |
0 |
0 |
T36 |
0 |
620 |
0 |
0 |
T37 |
0 |
316 |
0 |
0 |
T43 |
0 |
2243 |
0 |
0 |
T44 |
0 |
2582 |
0 |
0 |
T59 |
0 |
453 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
1893 |
0 |
0 |
T95 |
0 |
224 |
0 |
0 |
T96 |
0 |
339 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1820 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
1 |
0 |
0 |
T35 |
0 |
9 |
0 |
0 |
T36 |
0 |
2 |
0 |
0 |
T37 |
0 |
1 |
0 |
0 |
T43 |
0 |
7 |
0 |
0 |
T44 |
0 |
10 |
0 |
0 |
T59 |
0 |
1 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
1 |
0 |
0 |
T95 |
0 |
1 |
0 |
0 |
T96 |
0 |
1 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_com_out_ctl_3_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T34 T35 T36
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T34 T35 T36
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T34 T35 T36
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T34 T35 T36
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T34 T35 T36
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T34 T35 T36
135 1/1 txn_bits_q <= '0;
Tests: T34 T35 T36
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_com_out_ctl_3_cdc
| Total | Covered | Percent |
Conditions | 11 | 10 | 90.91 |
Logical | 11 | 10 | 90.91 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T34,T35,T36 |
1 | 1 | Covered | T34,T35,T36 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_com_out_ctl_3_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T34,T35,T36 |
0 |
0 |
1 |
Covered |
T34,T35,T36 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_com_out_ctl_3_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1660772 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
292 |
0 |
0 |
T35 |
0 |
3684 |
0 |
0 |
T36 |
0 |
665 |
0 |
0 |
T37 |
0 |
311 |
0 |
0 |
T43 |
0 |
2214 |
0 |
0 |
T44 |
0 |
2562 |
0 |
0 |
T59 |
0 |
443 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
1883 |
0 |
0 |
T95 |
0 |
298 |
0 |
0 |
T96 |
0 |
277 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1785 |
0 |
0 |
T8 |
132162 |
0 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
0 |
0 |
0 |
T34 |
735021 |
1 |
0 |
0 |
T35 |
0 |
9 |
0 |
0 |
T36 |
0 |
2 |
0 |
0 |
T37 |
0 |
1 |
0 |
0 |
T43 |
0 |
7 |
0 |
0 |
T44 |
0 |
10 |
0 |
0 |
T59 |
0 |
1 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T94 |
0 |
1 |
0 |
0 |
T95 |
0 |
1 |
0 |
0 |
T96 |
0 |
1 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_ulp_ctl_cdc
| Line No. | Total | Covered | Percent |
TOTAL | | 22 | 22 | 100.00 |
CONT_ASSIGN | 65 | 1 | 1 | 100.00 |
ALWAYS | 71 | 6 | 6 | 100.00 |
CONT_ASSIGN | 85 | 1 | 1 | 100.00 |
CONT_ASSIGN | 109 | 1 | 1 | 100.00 |
ALWAYS | 115 | 9 | 9 | 100.00 |
CONT_ASSIGN | 150 | 1 | 1 | 100.00 |
CONT_ASSIGN | 155 | 1 | 1 | 100.00 |
CONT_ASSIGN | 156 | 1 | 1 | 100.00 |
CONT_ASSIGN | 200 | 1 | 1 | 100.00 |
64
65 1/1 assign src_req = src_we_i | src_re_i;
Tests: T8 T11 T13
66
67 // busy indication back-pressures upstream if the register is accessed
68 // again. The busy indication is also used as a "commit" indication for
69 // resolving software and hardware write conflicts
70 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T8 T11 T13
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
76 1/1 src_busy_q <= 1'b0;
Tests: T8 T11 T13
77 end
MISSING_ELSE
78 end
79
80 // A src_ack should only be sent if there was a src_req.
81 // src_busy_q asserts whenever there is a src_req. By association,
82 // whenever src_ack is seen, then src_busy must be high.
83 `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84
85 1/1 assign src_busy_o = src_busy_q;
Tests: T4 T5 T6
86
87 // src_q acts as both the write holding register and the software read back
88 // register.
89 // When software performs a write, the write data is captured in src_q for
90 // CDC purposes. When not performing a write, the src_q reflects the most recent
91 // hardware value. For registers with no hardware access, this is simply the
92 // the value programmed by software (or in the case R1C, W1C etc) the value after
93 // the operation. For registers with hardware access, this reflects a potentially
94 // delayed version of the real value, as the software facing updates lag real
95 // time updates.
96 //
97 // To resolve software and hardware conflicts, the process is as follows:
98 // When software issues a write, this module asserts "busy". While busy,
99 // src_q does not take on destination value updates. Since the
100 // logic has committed to updating based on software command, there is an irreversible
101 // window from which hardware writes are ignored. Once the busy window completes,
102 // the cdc portion then begins sampling once more.
103 //
104 // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105 // software is always prioritized. The main difference is the conflict resolution window
106 // is now larger instead of just one destination clock cycle.
107
108 logic busy;
109 1/1 assign busy = src_busy_q & !src_ack;
Tests: T4 T5 T6
110
111 // This is the current destination value
112 logic [DataWidth-1:0] dst_qs;
113 logic src_update;
114 always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115 1/1 if (!rst_src_ni) begin
Tests: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: T8 T11 T13
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T8 T11 T13
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T8 T11 T13
135 1/1 txn_bits_q <= '0;
Tests: T8 T11 T13
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: T4 T5 T6
156 1/1 assign dst_wd_o = src_q;
Tests: T4 T5 T6
157
158 ////////////////////////////
159 // CDC handling
160 ////////////////////////////
161
162 logic dst_req_from_src;
163 logic dst_req;
164
165
166 // the software transaction is pulse synced across the domain.
167 // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168 prim_pulse_sync u_src_to_dst_req (
169 .clk_src_i,
170 .rst_src_ni,
171 .clk_dst_i,
172 .rst_dst_ni,
173 .src_pulse_i(src_req),
174 .dst_pulse_o(dst_req_from_src)
175 );
176
177 prim_reg_cdc_arb #(
178 .DataWidth(DataWidth),
179 .ResetVal(ResetVal),
180 .DstWrReq(DstWrReq)
181 ) u_arb (
182 .clk_src_i,
183 .rst_src_ni,
184 .clk_dst_i,
185 .rst_dst_ni,
186 .src_ack_o(src_ack),
187 .src_update_o(src_update),
188 .dst_req_i(dst_req_from_src),
189 .dst_req_o(dst_req),
190 .dst_update_i,
191 .dst_ds_i,
192 .dst_qs_i,
193 .dst_qs_o(dst_qs)
194 );
195
196
197 // Each is valid only when destination request pulse is high; this is important in not propagating
198 // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199 // reset.
200 1/1 assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
Tests: T4 T5 T6
Cond Coverage for Instance : tb.dut.u_reg.u_ulp_ctl_cdc
| Total | Covered | Percent |
Conditions | 13 | 12 | 92.31 |
Logical | 13 | 12 | 92.31 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T8,T11,T13 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Covered | T8,T11,T13 |
1 | 1 | Covered | T8,T11,T13 |
LINE 123
EXPRESSION (src_wd_i & BitMask)
----1--- ---2---
-1- | -2- | Status | Tests |
0 | - | Covered | T8,T11,T13 |
1 | - | Covered | T8,T11,T13 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T8,T11,T13 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T8,T11,T13 |
1 | 1 | Covered | T8,T11,T13 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_ulp_ctl_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T8,T11,T13 |
0 |
0 |
1 |
Covered |
T8,T11,T13 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T8,T11,T13 |
0 |
0 |
1 |
Covered |
T8,T11,T13 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_ulp_ctl_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
942877 |
0 |
0 |
T8 |
132162 |
532 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
2793 |
0 |
0 |
T13 |
0 |
965 |
0 |
0 |
T32 |
373680 |
0 |
0 |
0 |
T35 |
0 |
1609 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T70 |
0 |
1580 |
0 |
0 |
T71 |
0 |
1315 |
0 |
0 |
T72 |
0 |
1698 |
0 |
0 |
T73 |
0 |
870 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T98 |
0 |
1683 |
0 |
0 |
T99 |
0 |
341 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
8067428 |
7417551 |
0 |
0 |
T1 |
488 |
88 |
0 |
0 |
T4 |
496 |
96 |
0 |
0 |
T5 |
424 |
24 |
0 |
0 |
T6 |
455 |
55 |
0 |
0 |
T14 |
792 |
392 |
0 |
0 |
T15 |
502 |
102 |
0 |
0 |
T16 |
777 |
377 |
0 |
0 |
T17 |
429 |
29 |
0 |
0 |
T18 |
407 |
7 |
0 |
0 |
T23 |
455 |
55 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
985 |
0 |
0 |
T8 |
132162 |
2 |
0 |
0 |
T10 |
55652 |
0 |
0 |
0 |
T11 |
219320 |
2 |
0 |
0 |
T13 |
0 |
2 |
0 |
0 |
T32 |
373680 |
0 |
0 |
0 |
T35 |
0 |
4 |
0 |
0 |
T66 |
105753 |
0 |
0 |
0 |
T67 |
108335 |
0 |
0 |
0 |
T68 |
50482 |
0 |
0 |
0 |
T70 |
0 |
2 |
0 |
0 |
T71 |
0 |
2 |
0 |
0 |
T72 |
0 |
2 |
0 |
0 |
T73 |
0 |
2 |
0 |
0 |
T74 |
131848 |
0 |
0 |
0 |
T75 |
63172 |
0 |
0 |
0 |
T76 |
197645 |
0 |
0 |
0 |
T98 |
0 |
2 |
0 |
0 |
T99 |
0 |
2 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1226727766 |
1226293923 |
0 |
0 |
T1 |
114854 |
114785 |
0 |
0 |
T4 |
54651 |
54581 |
0 |
0 |
T5 |
65907 |
65818 |
0 |
0 |
T6 |
56928 |
56862 |
0 |
0 |
T14 |
51486 |
51397 |
0 |
0 |
T15 |
245841 |
245768 |
0 |
0 |
T16 |
194595 |
194529 |
0 |
0 |
T17 |
32200 |
32145 |
0 |
0 |
T18 |
50958 |
50892 |
0 |
0 |
T23 |
45481 |
45397 |
0 |
0 |