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: T1 T2 T3
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: T1 T2 T3
72 1/1 src_busy_q <= '0;
Tests: T1 T2 T3
73 1/1 end else if (src_req) begin
Tests: T1 T2 T3
74 1/1 src_busy_q <= 1'b1;
Tests: T1 T2 T3
75 1/1 end else if (src_ack) begin
Tests: T1 T2 T3
76 1/1 src_busy_q <= 1'b0;
Tests: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
116 1/1 src_q <= ResetVal;
Tests: T1 T2 T3
117 1/1 txn_bits_q <= '0;
Tests: T1 T2 T3
118 1/1 end else if (src_req) begin
Tests: T1 T2 T3
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: T1 T2 T3
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T1 T2 T3
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
156 1/1 assign dst_wd_o = src_q;
Tests: T1 T2 T3
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: T1 T2 T3
Cond Coverage for Module :
prim_reg_cdc ( parameter DataWidth=13,ResetVal=0,BitMask=8191,DstWrReq=0,TxnWidth=3 + DataWidth=32,ResetVal=0,BitMask=-1,DstWrReq=0,TxnWidth=3 + DataWidth=32,ResetVal=0,BitMask=-1,DstWrReq=1,TxnWidth=3 + DataWidth=2,ResetVal=0,BitMask=3,DstWrReq=0,TxnWidth=3 )
Cond Coverage for Module self-instances :
| Total | Covered | Percent |
Conditions | 14 | 13 | 92.86 |
Logical | 14 | 13 | 92.86 |
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 | T1,T2,T3 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T1,T2,T3 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Covered | T1,T2,T3 |
1 | 1 | Covered | T1,T2,T3 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T1,T2,T3 |
0 | 1 | Covered | T1,T4,T5 |
1 | 0 | Covered | T1,T2,T3 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T1,T2,T3 |
1 | 1 | Covered | T1,T2,T3 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Covered | T1,T2,T3 |
1 | 1 | Covered | T1,T4,T5 |
Cond Coverage for Module :
prim_reg_cdc ( parameter DataWidth=1,ResetVal=0,BitMask=1,DstWrReq=1,TxnWidth=3 )
Cond Coverage for Module self-instances :
| Total | Covered | Percent |
Conditions | 16 | 15 | 93.75 |
Logical | 16 | 15 | 93.75 |
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 | T1,T2,T3 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T1,T2,T3 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Covered | T1,T2,T3 |
1 | 1 | Covered | T1,T2,T3 |
LINE 123
EXPRESSION (src_wd_i & BitMask)
----1--- ---2---
-1- | -2- | Status | Tests |
0 | - | Covered | T1,T2,T3 |
1 | - | Covered | T38,T39,T40 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T1,T2,T3 |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Covered | T1,T2,T3 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T1,T2,T3 |
1 | 1 | Covered | T1,T2,T3 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Covered | T15,T19,T37 |
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 |
T1,T2,T3 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T1,T2,T3 |
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 |
T1,T2,T3 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T1,T2,T3 |
Assert Coverage for Module :
prim_reg_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
2147483647 |
28767380 |
0 |
0 |
T1 |
53000 |
3484 |
0 |
0 |
T2 |
91050 |
7760 |
0 |
0 |
T3 |
113420 |
9211 |
0 |
0 |
T4 |
407570 |
23363 |
0 |
0 |
T5 |
1974830 |
5458 |
0 |
0 |
T6 |
98140 |
5601 |
0 |
0 |
T7 |
371110 |
29164 |
0 |
0 |
T8 |
2486680 |
1499 |
0 |
0 |
T9 |
0 |
28201 |
0 |
0 |
T10 |
0 |
5158 |
0 |
0 |
T11 |
1011250 |
0 |
0 |
0 |
T12 |
2028710 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
18276180 |
17378390 |
0 |
0 |
T1 |
800 |
270 |
0 |
0 |
T2 |
710 |
180 |
0 |
0 |
T3 |
890 |
220 |
0 |
0 |
T4 |
830 |
190 |
0 |
0 |
T5 |
15780 |
15200 |
0 |
0 |
T6 |
810 |
250 |
0 |
0 |
T7 |
760 |
180 |
0 |
0 |
T8 |
82870 |
82290 |
0 |
0 |
T11 |
8780 |
100 |
0 |
0 |
T12 |
16220 |
230 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
2147483647 |
31680 |
0 |
0 |
T1 |
53000 |
15 |
0 |
0 |
T2 |
91050 |
18 |
0 |
0 |
T3 |
113420 |
18 |
0 |
0 |
T4 |
407570 |
13 |
0 |
0 |
T5 |
1974830 |
16 |
0 |
0 |
T6 |
98140 |
14 |
0 |
0 |
T7 |
371110 |
18 |
0 |
0 |
T8 |
2486680 |
16 |
0 |
0 |
T9 |
0 |
16 |
0 |
0 |
T10 |
0 |
14 |
0 |
0 |
T11 |
1011250 |
0 |
0 |
0 |
T12 |
2028710 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
2147483647 |
2147483647 |
0 |
0 |
T1 |
53000 |
52430 |
0 |
0 |
T2 |
91050 |
90440 |
0 |
0 |
T3 |
113420 |
112460 |
0 |
0 |
T4 |
407570 |
406720 |
0 |
0 |
T5 |
1974830 |
1973990 |
0 |
0 |
T6 |
98140 |
97350 |
0 |
0 |
T7 |
371110 |
370350 |
0 |
0 |
T8 |
2486680 |
2486100 |
0 |
0 |
T11 |
1011250 |
1003100 |
0 |
0 |
T12 |
2028710 |
2012860 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_wkup_count_hi_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: T1 T2 T3
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: T1 T2 T3
72 1/1 src_busy_q <= '0;
Tests: T1 T2 T3
73 1/1 end else if (src_req) begin
Tests: T1 T2 T3
74 1/1 src_busy_q <= 1'b1;
Tests: T1 T2 T3
75 1/1 end else if (src_ack) begin
Tests: T1 T2 T3
76 1/1 src_busy_q <= 1'b0;
Tests: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
116 1/1 src_q <= ResetVal;
Tests: T1 T2 T3
117 1/1 txn_bits_q <= '0;
Tests: T1 T2 T3
118 1/1 end else if (src_req) begin
Tests: T1 T2 T3
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: T1 T2 T3
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T1 T2 T3
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
156 1/1 assign dst_wd_o = src_q;
Tests: T1 T2 T3
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: T1 T2 T3
Cond Coverage for Instance : tb.dut.u_reg.u_wkup_count_hi_cdc
| Total | Covered | Percent |
Conditions | 14 | 10 | 71.43 |
Logical | 14 | 10 | 71.43 |
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 | T1,T2,T3 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T1,T2,T3 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Covered | T1,T2,T3 |
1 | 1 | Covered | T1,T2,T3 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T1,T2,T3 |
0 | 1 | Not Covered | |
1 | 0 | Covered | T1,T2,T3 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T1,T2,T3 |
1 | 1 | Covered | T1,T2,T3 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Not Covered | |
1 | 1 | Not Covered | |
Branch Coverage for Instance : tb.dut.u_reg.u_wkup_count_hi_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 |
T1,T2,T3 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T1,T2,T3 |
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 |
T1,T2,T3 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T1,T2,T3 |
Assert Coverage for Instance : tb.dut.u_reg.u_wkup_count_hi_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
3837583 |
0 |
0 |
T1 |
5300 |
458 |
0 |
0 |
T2 |
9105 |
1356 |
0 |
0 |
T3 |
11342 |
1540 |
0 |
0 |
T4 |
40757 |
3345 |
0 |
0 |
T5 |
197483 |
664 |
0 |
0 |
T6 |
9814 |
751 |
0 |
0 |
T7 |
37111 |
5261 |
0 |
0 |
T8 |
248668 |
195 |
0 |
0 |
T9 |
0 |
3337 |
0 |
0 |
T10 |
0 |
704 |
0 |
0 |
T11 |
101125 |
0 |
0 |
0 |
T12 |
202871 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1827618 |
1737839 |
0 |
0 |
T1 |
80 |
27 |
0 |
0 |
T2 |
71 |
18 |
0 |
0 |
T3 |
89 |
22 |
0 |
0 |
T4 |
83 |
19 |
0 |
0 |
T5 |
1578 |
1520 |
0 |
0 |
T6 |
81 |
25 |
0 |
0 |
T7 |
76 |
18 |
0 |
0 |
T8 |
8287 |
8229 |
0 |
0 |
T11 |
878 |
10 |
0 |
0 |
T12 |
1622 |
23 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
4130 |
0 |
0 |
T1 |
5300 |
2 |
0 |
0 |
T2 |
9105 |
3 |
0 |
0 |
T3 |
11342 |
3 |
0 |
0 |
T4 |
40757 |
2 |
0 |
0 |
T5 |
197483 |
2 |
0 |
0 |
T6 |
9814 |
2 |
0 |
0 |
T7 |
37111 |
3 |
0 |
0 |
T8 |
248668 |
2 |
0 |
0 |
T9 |
0 |
2 |
0 |
0 |
T10 |
0 |
2 |
0 |
0 |
T11 |
101125 |
0 |
0 |
0 |
T12 |
202871 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
468433778 |
0 |
0 |
T1 |
5300 |
5243 |
0 |
0 |
T2 |
9105 |
9044 |
0 |
0 |
T3 |
11342 |
11246 |
0 |
0 |
T4 |
40757 |
40672 |
0 |
0 |
T5 |
197483 |
197399 |
0 |
0 |
T6 |
9814 |
9735 |
0 |
0 |
T7 |
37111 |
37035 |
0 |
0 |
T8 |
248668 |
248610 |
0 |
0 |
T11 |
101125 |
100310 |
0 |
0 |
T12 |
202871 |
201286 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_wkup_ctrl_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: T1 T2 T3
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: T1 T2 T3
72 1/1 src_busy_q <= '0;
Tests: T1 T2 T3
73 1/1 end else if (src_req) begin
Tests: T1 T2 T3
74 1/1 src_busy_q <= 1'b1;
Tests: T1 T2 T3
75 1/1 end else if (src_ack) begin
Tests: T1 T2 T3
76 1/1 src_busy_q <= 1'b0;
Tests: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
116 1/1 src_q <= ResetVal;
Tests: T1 T2 T3
117 1/1 txn_bits_q <= '0;
Tests: T1 T2 T3
118 1/1 end else if (src_req) begin
Tests: T1 T2 T3
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: T1 T2 T3
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T1 T2 T3
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
156 1/1 assign dst_wd_o = src_q;
Tests: T1 T2 T3
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: T1 T2 T3
Cond Coverage for Instance : tb.dut.u_reg.u_wkup_ctrl_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 | T1,T2,T3 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T1,T2,T3 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Covered | T1,T2,T3 |
1 | 1 | Covered | T1,T2,T3 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T1,T2,T3 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T1,T2,T3 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T1,T2,T3 |
1 | 1 | Covered | T1,T2,T3 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_wkup_ctrl_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 |
T1,T2,T3 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T1,T2,T3 |
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 |
T1,T2,T3 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T1,T2,T3 |
Assert Coverage for Instance : tb.dut.u_reg.u_wkup_ctrl_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
3864012 |
0 |
0 |
T1 |
5300 |
445 |
0 |
0 |
T2 |
9105 |
746 |
0 |
0 |
T3 |
11342 |
966 |
0 |
0 |
T4 |
40757 |
3341 |
0 |
0 |
T5 |
197483 |
1144 |
0 |
0 |
T6 |
9814 |
727 |
0 |
0 |
T7 |
37111 |
2876 |
0 |
0 |
T8 |
248668 |
310 |
0 |
0 |
T9 |
0 |
4785 |
0 |
0 |
T10 |
0 |
700 |
0 |
0 |
T11 |
101125 |
0 |
0 |
0 |
T12 |
202871 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1827618 |
1737839 |
0 |
0 |
T1 |
80 |
27 |
0 |
0 |
T2 |
71 |
18 |
0 |
0 |
T3 |
89 |
22 |
0 |
0 |
T4 |
83 |
19 |
0 |
0 |
T5 |
1578 |
1520 |
0 |
0 |
T6 |
81 |
25 |
0 |
0 |
T7 |
76 |
18 |
0 |
0 |
T8 |
8287 |
8229 |
0 |
0 |
T11 |
878 |
10 |
0 |
0 |
T12 |
1622 |
23 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
4363 |
0 |
0 |
T1 |
5300 |
2 |
0 |
0 |
T2 |
9105 |
2 |
0 |
0 |
T3 |
11342 |
2 |
0 |
0 |
T4 |
40757 |
2 |
0 |
0 |
T5 |
197483 |
3 |
0 |
0 |
T6 |
9814 |
2 |
0 |
0 |
T7 |
37111 |
2 |
0 |
0 |
T8 |
248668 |
3 |
0 |
0 |
T9 |
0 |
3 |
0 |
0 |
T10 |
0 |
2 |
0 |
0 |
T11 |
101125 |
0 |
0 |
0 |
T12 |
202871 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
468433778 |
0 |
0 |
T1 |
5300 |
5243 |
0 |
0 |
T2 |
9105 |
9044 |
0 |
0 |
T3 |
11342 |
11246 |
0 |
0 |
T4 |
40757 |
40672 |
0 |
0 |
T5 |
197483 |
197399 |
0 |
0 |
T6 |
9814 |
9735 |
0 |
0 |
T7 |
37111 |
37035 |
0 |
0 |
T8 |
248668 |
248610 |
0 |
0 |
T11 |
101125 |
100310 |
0 |
0 |
T12 |
202871 |
201286 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_wkup_thold_hi_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: T1 T2 T3
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: T1 T2 T3
72 1/1 src_busy_q <= '0;
Tests: T1 T2 T3
73 1/1 end else if (src_req) begin
Tests: T1 T2 T3
74 1/1 src_busy_q <= 1'b1;
Tests: T1 T2 T3
75 1/1 end else if (src_ack) begin
Tests: T1 T2 T3
76 1/1 src_busy_q <= 1'b0;
Tests: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
116 1/1 src_q <= ResetVal;
Tests: T1 T2 T3
117 1/1 txn_bits_q <= '0;
Tests: T1 T2 T3
118 1/1 end else if (src_req) begin
Tests: T1 T2 T3
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: T1 T2 T3
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T1 T2 T3
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
156 1/1 assign dst_wd_o = src_q;
Tests: T1 T2 T3
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: T1 T2 T3
Cond Coverage for Instance : tb.dut.u_reg.u_wkup_thold_hi_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 | T1,T2,T3 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T1,T2,T3 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Covered | T1,T2,T3 |
1 | 1 | Covered | T1,T2,T3 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T1,T2,T3 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T1,T2,T3 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T1,T2,T3 |
1 | 1 | Covered | T1,T2,T3 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_wkup_thold_hi_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 |
T1,T2,T3 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T1,T2,T3 |
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 |
T1,T2,T3 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T1,T2,T3 |
Assert Coverage for Instance : tb.dut.u_reg.u_wkup_thold_hi_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
2061315 |
0 |
0 |
T1 |
5300 |
222 |
0 |
0 |
T2 |
9105 |
365 |
0 |
0 |
T3 |
11342 |
461 |
0 |
0 |
T4 |
40757 |
1430 |
0 |
0 |
T5 |
197483 |
322 |
0 |
0 |
T6 |
9814 |
434 |
0 |
0 |
T7 |
37111 |
1430 |
0 |
0 |
T8 |
248668 |
80 |
0 |
0 |
T9 |
0 |
1903 |
0 |
0 |
T10 |
0 |
350 |
0 |
0 |
T11 |
101125 |
0 |
0 |
0 |
T12 |
202871 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1827618 |
1737839 |
0 |
0 |
T1 |
80 |
27 |
0 |
0 |
T2 |
71 |
18 |
0 |
0 |
T3 |
89 |
22 |
0 |
0 |
T4 |
83 |
19 |
0 |
0 |
T5 |
1578 |
1520 |
0 |
0 |
T6 |
81 |
25 |
0 |
0 |
T7 |
76 |
18 |
0 |
0 |
T8 |
8287 |
8229 |
0 |
0 |
T11 |
878 |
10 |
0 |
0 |
T12 |
1622 |
23 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
2445 |
0 |
0 |
T1 |
5300 |
1 |
0 |
0 |
T2 |
9105 |
1 |
0 |
0 |
T3 |
11342 |
1 |
0 |
0 |
T4 |
40757 |
1 |
0 |
0 |
T5 |
197483 |
1 |
0 |
0 |
T6 |
9814 |
1 |
0 |
0 |
T7 |
37111 |
1 |
0 |
0 |
T8 |
248668 |
1 |
0 |
0 |
T9 |
0 |
1 |
0 |
0 |
T10 |
0 |
1 |
0 |
0 |
T11 |
101125 |
0 |
0 |
0 |
T12 |
202871 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
468433778 |
0 |
0 |
T1 |
5300 |
5243 |
0 |
0 |
T2 |
9105 |
9044 |
0 |
0 |
T3 |
11342 |
11246 |
0 |
0 |
T4 |
40757 |
40672 |
0 |
0 |
T5 |
197483 |
197399 |
0 |
0 |
T6 |
9814 |
9735 |
0 |
0 |
T7 |
37111 |
37035 |
0 |
0 |
T8 |
248668 |
248610 |
0 |
0 |
T11 |
101125 |
100310 |
0 |
0 |
T12 |
202871 |
201286 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_wkup_thold_lo_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: T1 T2 T3
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: T1 T2 T3
72 1/1 src_busy_q <= '0;
Tests: T1 T2 T3
73 1/1 end else if (src_req) begin
Tests: T1 T2 T3
74 1/1 src_busy_q <= 1'b1;
Tests: T1 T2 T3
75 1/1 end else if (src_ack) begin
Tests: T1 T2 T3
76 1/1 src_busy_q <= 1'b0;
Tests: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
116 1/1 src_q <= ResetVal;
Tests: T1 T2 T3
117 1/1 txn_bits_q <= '0;
Tests: T1 T2 T3
118 1/1 end else if (src_req) begin
Tests: T1 T2 T3
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: T1 T2 T3
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T1 T2 T3
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
156 1/1 assign dst_wd_o = src_q;
Tests: T1 T2 T3
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: T1 T2 T3
Cond Coverage for Instance : tb.dut.u_reg.u_wkup_thold_lo_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 | T1,T2,T3 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T1,T2,T3 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Covered | T1,T2,T3 |
1 | 1 | Covered | T1,T2,T3 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T1,T2,T3 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T1,T2,T3 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T1,T2,T3 |
1 | 1 | Covered | T1,T2,T3 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_wkup_thold_lo_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 |
T1,T2,T3 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T1,T2,T3 |
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 |
T1,T2,T3 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T1,T2,T3 |
Assert Coverage for Instance : tb.dut.u_reg.u_wkup_thold_lo_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
2043688 |
0 |
0 |
T1 |
5300 |
228 |
0 |
0 |
T2 |
9105 |
367 |
0 |
0 |
T3 |
11342 |
471 |
0 |
0 |
T4 |
40757 |
1432 |
0 |
0 |
T5 |
197483 |
334 |
0 |
0 |
T6 |
9814 |
443 |
0 |
0 |
T7 |
37111 |
1432 |
0 |
0 |
T8 |
248668 |
82 |
0 |
0 |
T9 |
0 |
1914 |
0 |
0 |
T10 |
0 |
352 |
0 |
0 |
T11 |
101125 |
0 |
0 |
0 |
T12 |
202871 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1827618 |
1737839 |
0 |
0 |
T1 |
80 |
27 |
0 |
0 |
T2 |
71 |
18 |
0 |
0 |
T3 |
89 |
22 |
0 |
0 |
T4 |
83 |
19 |
0 |
0 |
T5 |
1578 |
1520 |
0 |
0 |
T6 |
81 |
25 |
0 |
0 |
T7 |
76 |
18 |
0 |
0 |
T8 |
8287 |
8229 |
0 |
0 |
T11 |
878 |
10 |
0 |
0 |
T12 |
1622 |
23 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
2446 |
0 |
0 |
T1 |
5300 |
1 |
0 |
0 |
T2 |
9105 |
1 |
0 |
0 |
T3 |
11342 |
1 |
0 |
0 |
T4 |
40757 |
1 |
0 |
0 |
T5 |
197483 |
1 |
0 |
0 |
T6 |
9814 |
1 |
0 |
0 |
T7 |
37111 |
1 |
0 |
0 |
T8 |
248668 |
1 |
0 |
0 |
T9 |
0 |
1 |
0 |
0 |
T10 |
0 |
1 |
0 |
0 |
T11 |
101125 |
0 |
0 |
0 |
T12 |
202871 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
468433778 |
0 |
0 |
T1 |
5300 |
5243 |
0 |
0 |
T2 |
9105 |
9044 |
0 |
0 |
T3 |
11342 |
11246 |
0 |
0 |
T4 |
40757 |
40672 |
0 |
0 |
T5 |
197483 |
197399 |
0 |
0 |
T6 |
9814 |
9735 |
0 |
0 |
T7 |
37111 |
37035 |
0 |
0 |
T8 |
248668 |
248610 |
0 |
0 |
T11 |
101125 |
100310 |
0 |
0 |
T12 |
202871 |
201286 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_wdog_ctrl_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: T1 T2 T3
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: T1 T2 T3
72 1/1 src_busy_q <= '0;
Tests: T1 T2 T3
73 1/1 end else if (src_req) begin
Tests: T1 T2 T3
74 1/1 src_busy_q <= 1'b1;
Tests: T1 T2 T3
75 1/1 end else if (src_ack) begin
Tests: T1 T2 T3
76 1/1 src_busy_q <= 1'b0;
Tests: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
116 1/1 src_q <= ResetVal;
Tests: T1 T2 T3
117 1/1 txn_bits_q <= '0;
Tests: T1 T2 T3
118 1/1 end else if (src_req) begin
Tests: T1 T2 T3
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: T1 T2 T3
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T1 T2 T3
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
156 1/1 assign dst_wd_o = src_q;
Tests: T1 T2 T3
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: T1 T2 T3
Cond Coverage for Instance : tb.dut.u_reg.u_wdog_ctrl_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 | T1,T2,T3 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T1,T2,T3 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Covered | T1,T2,T3 |
1 | 1 | Covered | T1,T2,T3 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T1,T2,T3 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T1,T2,T3 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T1,T2,T3 |
1 | 1 | Covered | T1,T2,T3 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_wdog_ctrl_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 |
T1,T2,T3 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T1,T2,T3 |
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 |
T1,T2,T3 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T1,T2,T3 |
Assert Coverage for Instance : tb.dut.u_reg.u_wdog_ctrl_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
3039549 |
0 |
0 |
T1 |
5300 |
496 |
0 |
0 |
T2 |
9105 |
746 |
0 |
0 |
T3 |
11342 |
969 |
0 |
0 |
T4 |
40757 |
1436 |
0 |
0 |
T5 |
197483 |
716 |
0 |
0 |
T6 |
9814 |
455 |
0 |
0 |
T7 |
37111 |
2876 |
0 |
0 |
T8 |
248668 |
203 |
0 |
0 |
T9 |
0 |
3391 |
0 |
0 |
T10 |
0 |
356 |
0 |
0 |
T11 |
101125 |
0 |
0 |
0 |
T12 |
202871 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1827618 |
1737839 |
0 |
0 |
T1 |
80 |
27 |
0 |
0 |
T2 |
71 |
18 |
0 |
0 |
T3 |
89 |
22 |
0 |
0 |
T4 |
83 |
19 |
0 |
0 |
T5 |
1578 |
1520 |
0 |
0 |
T6 |
81 |
25 |
0 |
0 |
T7 |
76 |
18 |
0 |
0 |
T8 |
8287 |
8229 |
0 |
0 |
T11 |
878 |
10 |
0 |
0 |
T12 |
1622 |
23 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
3410 |
0 |
0 |
T1 |
5300 |
2 |
0 |
0 |
T2 |
9105 |
2 |
0 |
0 |
T3 |
11342 |
2 |
0 |
0 |
T4 |
40757 |
1 |
0 |
0 |
T5 |
197483 |
2 |
0 |
0 |
T6 |
9814 |
1 |
0 |
0 |
T7 |
37111 |
2 |
0 |
0 |
T8 |
248668 |
2 |
0 |
0 |
T9 |
0 |
2 |
0 |
0 |
T10 |
0 |
1 |
0 |
0 |
T11 |
101125 |
0 |
0 |
0 |
T12 |
202871 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
468433778 |
0 |
0 |
T1 |
5300 |
5243 |
0 |
0 |
T2 |
9105 |
9044 |
0 |
0 |
T3 |
11342 |
11246 |
0 |
0 |
T4 |
40757 |
40672 |
0 |
0 |
T5 |
197483 |
197399 |
0 |
0 |
T6 |
9814 |
9735 |
0 |
0 |
T7 |
37111 |
37035 |
0 |
0 |
T8 |
248668 |
248610 |
0 |
0 |
T11 |
101125 |
100310 |
0 |
0 |
T12 |
202871 |
201286 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_wdog_bark_thold_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: T1 T2 T3
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: T1 T2 T3
72 1/1 src_busy_q <= '0;
Tests: T1 T2 T3
73 1/1 end else if (src_req) begin
Tests: T1 T2 T3
74 1/1 src_busy_q <= 1'b1;
Tests: T1 T2 T3
75 1/1 end else if (src_ack) begin
Tests: T1 T2 T3
76 1/1 src_busy_q <= 1'b0;
Tests: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
116 1/1 src_q <= ResetVal;
Tests: T1 T2 T3
117 1/1 txn_bits_q <= '0;
Tests: T1 T2 T3
118 1/1 end else if (src_req) begin
Tests: T1 T2 T3
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: T1 T2 T3
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T1 T2 T3
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
156 1/1 assign dst_wd_o = src_q;
Tests: T1 T2 T3
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: T1 T2 T3
Cond Coverage for Instance : tb.dut.u_reg.u_wdog_bark_thold_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 | T1,T2,T3 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T1,T2,T3 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Covered | T1,T2,T3 |
1 | 1 | Covered | T1,T2,T3 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T1,T2,T3 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T1,T2,T3 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T1,T2,T3 |
1 | 1 | Covered | T1,T2,T3 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_wdog_bark_thold_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 |
T1,T2,T3 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T1,T2,T3 |
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 |
T1,T2,T3 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T1,T2,T3 |
Assert Coverage for Instance : tb.dut.u_reg.u_wdog_bark_thold_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
2040201 |
0 |
0 |
T1 |
5300 |
216 |
0 |
0 |
T2 |
9105 |
363 |
0 |
0 |
T3 |
11342 |
452 |
0 |
0 |
T4 |
40757 |
1428 |
0 |
0 |
T5 |
197483 |
305 |
0 |
0 |
T6 |
9814 |
426 |
0 |
0 |
T7 |
37111 |
1428 |
0 |
0 |
T8 |
248668 |
78 |
0 |
0 |
T9 |
0 |
1890 |
0 |
0 |
T10 |
0 |
348 |
0 |
0 |
T11 |
101125 |
0 |
0 |
0 |
T12 |
202871 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1827618 |
1737839 |
0 |
0 |
T1 |
80 |
27 |
0 |
0 |
T2 |
71 |
18 |
0 |
0 |
T3 |
89 |
22 |
0 |
0 |
T4 |
83 |
19 |
0 |
0 |
T5 |
1578 |
1520 |
0 |
0 |
T6 |
81 |
25 |
0 |
0 |
T7 |
76 |
18 |
0 |
0 |
T8 |
8287 |
8229 |
0 |
0 |
T11 |
878 |
10 |
0 |
0 |
T12 |
1622 |
23 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
2421 |
0 |
0 |
T1 |
5300 |
1 |
0 |
0 |
T2 |
9105 |
1 |
0 |
0 |
T3 |
11342 |
1 |
0 |
0 |
T4 |
40757 |
1 |
0 |
0 |
T5 |
197483 |
1 |
0 |
0 |
T6 |
9814 |
1 |
0 |
0 |
T7 |
37111 |
1 |
0 |
0 |
T8 |
248668 |
1 |
0 |
0 |
T9 |
0 |
1 |
0 |
0 |
T10 |
0 |
1 |
0 |
0 |
T11 |
101125 |
0 |
0 |
0 |
T12 |
202871 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
468433778 |
0 |
0 |
T1 |
5300 |
5243 |
0 |
0 |
T2 |
9105 |
9044 |
0 |
0 |
T3 |
11342 |
11246 |
0 |
0 |
T4 |
40757 |
40672 |
0 |
0 |
T5 |
197483 |
197399 |
0 |
0 |
T6 |
9814 |
9735 |
0 |
0 |
T7 |
37111 |
37035 |
0 |
0 |
T8 |
248668 |
248610 |
0 |
0 |
T11 |
101125 |
100310 |
0 |
0 |
T12 |
202871 |
201286 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_wdog_bite_thold_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: T1 T2 T3
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: T1 T2 T3
72 1/1 src_busy_q <= '0;
Tests: T1 T2 T3
73 1/1 end else if (src_req) begin
Tests: T1 T2 T3
74 1/1 src_busy_q <= 1'b1;
Tests: T1 T2 T3
75 1/1 end else if (src_ack) begin
Tests: T1 T2 T3
76 1/1 src_busy_q <= 1'b0;
Tests: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
116 1/1 src_q <= ResetVal;
Tests: T1 T2 T3
117 1/1 txn_bits_q <= '0;
Tests: T1 T2 T3
118 1/1 end else if (src_req) begin
Tests: T1 T2 T3
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: T1 T2 T3
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T1 T2 T3
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
156 1/1 assign dst_wd_o = src_q;
Tests: T1 T2 T3
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: T1 T2 T3
Cond Coverage for Instance : tb.dut.u_reg.u_wdog_bite_thold_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 | T1,T2,T3 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T1,T2,T3 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Covered | T1,T2,T3 |
1 | 1 | Covered | T1,T2,T3 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T1,T2,T3 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T1,T2,T3 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T1,T2,T3 |
1 | 1 | Covered | T1,T2,T3 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_wdog_bite_thold_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 |
T1,T2,T3 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T1,T2,T3 |
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 |
T1,T2,T3 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T1,T2,T3 |
Assert Coverage for Instance : tb.dut.u_reg.u_wdog_bite_thold_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
2072960 |
0 |
0 |
T1 |
5300 |
214 |
0 |
0 |
T2 |
9105 |
361 |
0 |
0 |
T3 |
11342 |
443 |
0 |
0 |
T4 |
40757 |
1426 |
0 |
0 |
T5 |
197483 |
296 |
0 |
0 |
T6 |
9814 |
410 |
0 |
0 |
T7 |
37111 |
1426 |
0 |
0 |
T8 |
248668 |
76 |
0 |
0 |
T9 |
0 |
1883 |
0 |
0 |
T10 |
0 |
346 |
0 |
0 |
T11 |
101125 |
0 |
0 |
0 |
T12 |
202871 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1827618 |
1737839 |
0 |
0 |
T1 |
80 |
27 |
0 |
0 |
T2 |
71 |
18 |
0 |
0 |
T3 |
89 |
22 |
0 |
0 |
T4 |
83 |
19 |
0 |
0 |
T5 |
1578 |
1520 |
0 |
0 |
T6 |
81 |
25 |
0 |
0 |
T7 |
76 |
18 |
0 |
0 |
T8 |
8287 |
8229 |
0 |
0 |
T11 |
878 |
10 |
0 |
0 |
T12 |
1622 |
23 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
2444 |
0 |
0 |
T1 |
5300 |
1 |
0 |
0 |
T2 |
9105 |
1 |
0 |
0 |
T3 |
11342 |
1 |
0 |
0 |
T4 |
40757 |
1 |
0 |
0 |
T5 |
197483 |
1 |
0 |
0 |
T6 |
9814 |
1 |
0 |
0 |
T7 |
37111 |
1 |
0 |
0 |
T8 |
248668 |
1 |
0 |
0 |
T9 |
0 |
1 |
0 |
0 |
T10 |
0 |
1 |
0 |
0 |
T11 |
101125 |
0 |
0 |
0 |
T12 |
202871 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
468433778 |
0 |
0 |
T1 |
5300 |
5243 |
0 |
0 |
T2 |
9105 |
9044 |
0 |
0 |
T3 |
11342 |
11246 |
0 |
0 |
T4 |
40757 |
40672 |
0 |
0 |
T5 |
197483 |
197399 |
0 |
0 |
T6 |
9814 |
9735 |
0 |
0 |
T7 |
37111 |
37035 |
0 |
0 |
T8 |
248668 |
248610 |
0 |
0 |
T11 |
101125 |
100310 |
0 |
0 |
T12 |
202871 |
201286 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_wkup_count_lo_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: T1 T2 T3
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: T1 T2 T3
72 1/1 src_busy_q <= '0;
Tests: T1 T2 T3
73 1/1 end else if (src_req) begin
Tests: T1 T2 T3
74 1/1 src_busy_q <= 1'b1;
Tests: T1 T2 T3
75 1/1 end else if (src_ack) begin
Tests: T1 T2 T3
76 1/1 src_busy_q <= 1'b0;
Tests: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
116 1/1 src_q <= ResetVal;
Tests: T1 T2 T3
117 1/1 txn_bits_q <= '0;
Tests: T1 T2 T3
118 1/1 end else if (src_req) begin
Tests: T1 T2 T3
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: T1 T2 T3
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T1 T2 T3
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
156 1/1 assign dst_wd_o = src_q;
Tests: T1 T2 T3
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: T1 T2 T3
Cond Coverage for Instance : tb.dut.u_reg.u_wkup_count_lo_cdc
| Total | Covered | Percent |
Conditions | 14 | 13 | 92.86 |
Logical | 14 | 13 | 92.86 |
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 | T1,T2,T3 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T1,T2,T3 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Covered | T1,T2,T3 |
1 | 1 | Covered | T1,T2,T3 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T1,T2,T3 |
0 | 1 | Covered | T1,T4,T5 |
1 | 0 | Covered | T1,T2,T3 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T1,T2,T3 |
1 | 1 | Covered | T1,T2,T3 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Covered | T1,T2,T3 |
1 | 1 | Covered | T1,T4,T5 |
Branch Coverage for Instance : tb.dut.u_reg.u_wkup_count_lo_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 |
T1,T2,T3 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T1,T2,T3 |
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 |
T1,T2,T3 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T1,T2,T3 |
Assert Coverage for Instance : tb.dut.u_reg.u_wkup_count_lo_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
4112386 |
0 |
0 |
T1 |
5300 |
532 |
0 |
0 |
T2 |
9105 |
1737 |
0 |
0 |
T3 |
11342 |
1933 |
0 |
0 |
T4 |
40757 |
4749 |
0 |
0 |
T5 |
197483 |
684 |
0 |
0 |
T6 |
9814 |
775 |
0 |
0 |
T7 |
37111 |
5746 |
0 |
0 |
T8 |
248668 |
199 |
0 |
0 |
T9 |
0 |
3854 |
0 |
0 |
T10 |
0 |
948 |
0 |
0 |
T11 |
101125 |
0 |
0 |
0 |
T12 |
202871 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1827618 |
1737839 |
0 |
0 |
T1 |
80 |
27 |
0 |
0 |
T2 |
71 |
18 |
0 |
0 |
T3 |
89 |
22 |
0 |
0 |
T4 |
83 |
19 |
0 |
0 |
T5 |
1578 |
1520 |
0 |
0 |
T6 |
81 |
25 |
0 |
0 |
T7 |
76 |
18 |
0 |
0 |
T8 |
8287 |
8229 |
0 |
0 |
T11 |
878 |
10 |
0 |
0 |
T12 |
1622 |
23 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
4035 |
0 |
0 |
T1 |
5300 |
2 |
0 |
0 |
T2 |
9105 |
3 |
0 |
0 |
T3 |
11342 |
3 |
0 |
0 |
T4 |
40757 |
1 |
0 |
0 |
T5 |
197483 |
2 |
0 |
0 |
T6 |
9814 |
2 |
0 |
0 |
T7 |
37111 |
3 |
0 |
0 |
T8 |
248668 |
2 |
0 |
0 |
T9 |
0 |
2 |
0 |
0 |
T10 |
0 |
2 |
0 |
0 |
T11 |
101125 |
0 |
0 |
0 |
T12 |
202871 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
468433778 |
0 |
0 |
T1 |
5300 |
5243 |
0 |
0 |
T2 |
9105 |
9044 |
0 |
0 |
T3 |
11342 |
11246 |
0 |
0 |
T4 |
40757 |
40672 |
0 |
0 |
T5 |
197483 |
197399 |
0 |
0 |
T6 |
9814 |
9735 |
0 |
0 |
T7 |
37111 |
37035 |
0 |
0 |
T8 |
248668 |
248610 |
0 |
0 |
T11 |
101125 |
100310 |
0 |
0 |
T12 |
202871 |
201286 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_wdog_count_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: T1 T2 T3
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: T1 T2 T3
72 1/1 src_busy_q <= '0;
Tests: T1 T2 T3
73 1/1 end else if (src_req) begin
Tests: T1 T2 T3
74 1/1 src_busy_q <= 1'b1;
Tests: T1 T2 T3
75 1/1 end else if (src_ack) begin
Tests: T1 T2 T3
76 1/1 src_busy_q <= 1'b0;
Tests: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
116 1/1 src_q <= ResetVal;
Tests: T1 T2 T3
117 1/1 txn_bits_q <= '0;
Tests: T1 T2 T3
118 1/1 end else if (src_req) begin
Tests: T1 T2 T3
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: T1 T2 T3
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T1 T2 T3
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
156 1/1 assign dst_wd_o = src_q;
Tests: T1 T2 T3
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: T1 T2 T3
Cond Coverage for Instance : tb.dut.u_reg.u_wdog_count_cdc
| Total | Covered | Percent |
Conditions | 14 | 13 | 92.86 |
Logical | 14 | 13 | 92.86 |
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 | T1,T2,T3 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T1,T2,T3 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Covered | T1,T2,T3 |
1 | 1 | Covered | T1,T2,T3 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T1,T2,T3 |
0 | 1 | Covered | T15,T16,T17 |
1 | 0 | Covered | T1,T2,T3 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T1,T2,T3 |
1 | 1 | Covered | T1,T2,T3 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Covered | T15,T17,T18 |
1 | 1 | Covered | T15,T16,T17 |
Branch Coverage for Instance : tb.dut.u_reg.u_wdog_count_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 |
T1,T2,T3 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T1,T2,T3 |
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 |
T1,T2,T3 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T1,T2,T3 |
Assert Coverage for Instance : tb.dut.u_reg.u_wdog_count_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
3901363 |
0 |
0 |
T1 |
5300 |
438 |
0 |
0 |
T2 |
9105 |
1350 |
0 |
0 |
T3 |
11342 |
1515 |
0 |
0 |
T4 |
40757 |
3341 |
0 |
0 |
T5 |
197483 |
648 |
0 |
0 |
T6 |
9814 |
735 |
0 |
0 |
T7 |
37111 |
5255 |
0 |
0 |
T8 |
248668 |
191 |
0 |
0 |
T9 |
0 |
3324 |
0 |
0 |
T10 |
0 |
700 |
0 |
0 |
T11 |
101125 |
0 |
0 |
0 |
T12 |
202871 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1827618 |
1737839 |
0 |
0 |
T1 |
80 |
27 |
0 |
0 |
T2 |
71 |
18 |
0 |
0 |
T3 |
89 |
22 |
0 |
0 |
T4 |
83 |
19 |
0 |
0 |
T5 |
1578 |
1520 |
0 |
0 |
T6 |
81 |
25 |
0 |
0 |
T7 |
76 |
18 |
0 |
0 |
T8 |
8287 |
8229 |
0 |
0 |
T11 |
878 |
10 |
0 |
0 |
T12 |
1622 |
23 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
4072 |
0 |
0 |
T1 |
5300 |
2 |
0 |
0 |
T2 |
9105 |
3 |
0 |
0 |
T3 |
11342 |
3 |
0 |
0 |
T4 |
40757 |
2 |
0 |
0 |
T5 |
197483 |
2 |
0 |
0 |
T6 |
9814 |
2 |
0 |
0 |
T7 |
37111 |
3 |
0 |
0 |
T8 |
248668 |
2 |
0 |
0 |
T9 |
0 |
2 |
0 |
0 |
T10 |
0 |
2 |
0 |
0 |
T11 |
101125 |
0 |
0 |
0 |
T12 |
202871 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
468433778 |
0 |
0 |
T1 |
5300 |
5243 |
0 |
0 |
T2 |
9105 |
9044 |
0 |
0 |
T3 |
11342 |
11246 |
0 |
0 |
T4 |
40757 |
40672 |
0 |
0 |
T5 |
197483 |
197399 |
0 |
0 |
T6 |
9814 |
9735 |
0 |
0 |
T7 |
37111 |
37035 |
0 |
0 |
T8 |
248668 |
248610 |
0 |
0 |
T11 |
101125 |
100310 |
0 |
0 |
T12 |
202871 |
201286 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_wkup_cause_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: T1 T2 T3
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: T1 T2 T3
72 1/1 src_busy_q <= '0;
Tests: T1 T2 T3
73 1/1 end else if (src_req) begin
Tests: T1 T2 T3
74 1/1 src_busy_q <= 1'b1;
Tests: T1 T2 T3
75 1/1 end else if (src_ack) begin
Tests: T1 T2 T3
76 1/1 src_busy_q <= 1'b0;
Tests: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
116 1/1 src_q <= ResetVal;
Tests: T1 T2 T3
117 1/1 txn_bits_q <= '0;
Tests: T1 T2 T3
118 1/1 end else if (src_req) begin
Tests: T1 T2 T3
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: T1 T2 T3
124 1/1 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
Tests: T1 T2 T3
125 1/1 end else if (src_busy_q && src_ack || src_update && !busy) begin
Tests: T1 T2 T3
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: T1 T2 T3
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: T1 T2 T3
156 1/1 assign dst_wd_o = src_q;
Tests: T1 T2 T3
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: T1 T2 T3
Cond Coverage for Instance : tb.dut.u_reg.u_wkup_cause_cdc
| Total | Covered | Percent |
Conditions | 16 | 15 | 93.75 |
Logical | 16 | 15 | 93.75 |
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 | T1,T2,T3 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T1,T2,T3 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Covered | T1,T2,T3 |
1 | 1 | Covered | T1,T2,T3 |
LINE 123
EXPRESSION (src_wd_i & BitMask)
----1--- ---2---
-1- | -2- | Status | Tests |
0 | - | Covered | T1,T2,T3 |
1 | - | Covered | T38,T39,T40 |
LINE 125
EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
-----------1----------- ------------2------------
-1- | -2- | Status | Tests |
0 | 0 | Covered | T1,T2,T3 |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Covered | T1,T2,T3 |
LINE 125
SUB-EXPRESSION (src_busy_q && src_ack)
-----1---- ---2---
-1- | -2- | Status | Tests |
0 | 1 | Not Covered | |
1 | 0 | Covered | T1,T2,T3 |
1 | 1 | Covered | T1,T2,T3 |
LINE 125
SUB-EXPRESSION (src_update && ((!busy)))
-----1---- ----2----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T1,T2,T3 |
1 | 0 | Covered | T15,T19,T37 |
1 | 1 | Covered | T1,T2,T3 |
Branch Coverage for Instance : tb.dut.u_reg.u_wkup_cause_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 |
T1,T2,T3 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T1,T2,T3 |
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 |
T1,T2,T3 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T1,T2,T3 |
Assert Coverage for Instance : tb.dut.u_reg.u_wkup_cause_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
1794323 |
0 |
0 |
T1 |
5300 |
235 |
0 |
0 |
T2 |
9105 |
369 |
0 |
0 |
T3 |
11342 |
461 |
0 |
0 |
T4 |
40757 |
1435 |
0 |
0 |
T5 |
197483 |
345 |
0 |
0 |
T6 |
9814 |
445 |
0 |
0 |
T7 |
37111 |
1434 |
0 |
0 |
T8 |
248668 |
85 |
0 |
0 |
T9 |
0 |
1920 |
0 |
0 |
T10 |
0 |
354 |
0 |
0 |
T11 |
101125 |
0 |
0 |
0 |
T12 |
202871 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
1827618 |
1737839 |
0 |
0 |
T1 |
80 |
27 |
0 |
0 |
T2 |
71 |
18 |
0 |
0 |
T3 |
89 |
22 |
0 |
0 |
T4 |
83 |
19 |
0 |
0 |
T5 |
1578 |
1520 |
0 |
0 |
T6 |
81 |
25 |
0 |
0 |
T7 |
76 |
18 |
0 |
0 |
T8 |
8287 |
8229 |
0 |
0 |
T11 |
878 |
10 |
0 |
0 |
T12 |
1622 |
23 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
1914 |
0 |
0 |
T1 |
5300 |
1 |
0 |
0 |
T2 |
9105 |
1 |
0 |
0 |
T3 |
11342 |
1 |
0 |
0 |
T4 |
40757 |
1 |
0 |
0 |
T5 |
197483 |
1 |
0 |
0 |
T6 |
9814 |
1 |
0 |
0 |
T7 |
37111 |
1 |
0 |
0 |
T8 |
248668 |
1 |
0 |
0 |
T9 |
0 |
1 |
0 |
0 |
T10 |
0 |
1 |
0 |
0 |
T11 |
101125 |
0 |
0 |
0 |
T12 |
202871 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
468637740 |
468433778 |
0 |
0 |
T1 |
5300 |
5243 |
0 |
0 |
T2 |
9105 |
9044 |
0 |
0 |
T3 |
11342 |
11246 |
0 |
0 |
T4 |
40757 |
40672 |
0 |
0 |
T5 |
197483 |
197399 |
0 |
0 |
T6 |
9814 |
9735 |
0 |
0 |
T7 |
37111 |
37035 |
0 |
0 |
T8 |
248668 |
248610 |
0 |
0 |
T11 |
101125 |
100310 |
0 |
0 |
T12 |
202871 |
201286 |
0 |
0 |