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: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T1 T2 T3
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
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: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: 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: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T1 T2 T3
135 1/1 txn_bits_q <= '0;
Tests: T1 T2 T3
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: 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
| Total | Covered | Percent |
Conditions | 15 | 13 | 86.67 |
Logical | 15 | 13 | 86.67 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Covered | T1,T2,T10 |
1 | 0 | Covered | T1,T2,T3 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
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 | T4,T5,T6 |
0 | 1 | Covered | T7,T8,T9 |
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 | T4,T5,T6 |
1 | 0 | Not Covered | |
1 | 1 | Covered | T7,T8,T9 |
Branch Coverage for Module :
prim_reg_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Module :
prim_reg_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
405451460 |
779510 |
0 |
0 |
T1 |
279780 |
1112 |
0 |
0 |
T2 |
0 |
925 |
0 |
0 |
T3 |
0 |
851 |
0 |
0 |
T10 |
0 |
611 |
0 |
0 |
T27 |
0 |
610 |
0 |
0 |
T39 |
0 |
148 |
0 |
0 |
T44 |
0 |
510 |
0 |
0 |
T45 |
0 |
384 |
0 |
0 |
T47 |
0 |
976 |
0 |
0 |
T48 |
0 |
82 |
0 |
0 |
T49 |
14570 |
0 |
0 |
0 |
T50 |
11110 |
0 |
0 |
0 |
T51 |
23160 |
0 |
0 |
0 |
T52 |
12590 |
0 |
0 |
0 |
T53 |
22340 |
0 |
0 |
0 |
T54 |
95240 |
0 |
0 |
0 |
T55 |
7570 |
0 |
0 |
0 |
T56 |
15680 |
0 |
0 |
0 |
T57 |
9780 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
627010492 |
603342164 |
0 |
0 |
T4 |
11070 |
10114 |
0 |
0 |
T5 |
13388 |
12642 |
0 |
0 |
T6 |
15326 |
14436 |
0 |
0 |
T28 |
13550 |
13080 |
0 |
0 |
T29 |
9746 |
8386 |
0 |
0 |
T30 |
9722 |
8692 |
0 |
0 |
T31 |
57540 |
56224 |
0 |
0 |
T32 |
13868 |
12820 |
0 |
0 |
T33 |
39410 |
38544 |
0 |
0 |
T34 |
62756 |
61238 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
405451460 |
157584 |
0 |
0 |
T1 |
279780 |
140 |
0 |
0 |
T2 |
0 |
200 |
0 |
0 |
T3 |
0 |
100 |
0 |
0 |
T10 |
0 |
177 |
0 |
0 |
T27 |
0 |
120 |
0 |
0 |
T39 |
0 |
40 |
0 |
0 |
T44 |
0 |
120 |
0 |
0 |
T45 |
0 |
80 |
0 |
0 |
T47 |
0 |
280 |
0 |
0 |
T48 |
0 |
20 |
0 |
0 |
T49 |
14570 |
0 |
0 |
0 |
T50 |
11110 |
0 |
0 |
0 |
T51 |
23160 |
0 |
0 |
0 |
T52 |
12590 |
0 |
0 |
0 |
T53 |
22340 |
0 |
0 |
0 |
T54 |
95240 |
0 |
0 |
0 |
T55 |
7570 |
0 |
0 |
0 |
T56 |
15680 |
0 |
0 |
0 |
T57 |
9780 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
405451460 |
382682160 |
0 |
0 |
T4 |
8840 |
7920 |
0 |
0 |
T5 |
20350 |
19010 |
0 |
0 |
T6 |
23140 |
21510 |
0 |
0 |
T28 |
20850 |
20010 |
0 |
0 |
T29 |
15240 |
12900 |
0 |
0 |
T30 |
14820 |
13180 |
0 |
0 |
T31 |
21020 |
20470 |
0 |
0 |
T32 |
21370 |
19470 |
0 |
0 |
T33 |
23810 |
23170 |
0 |
0 |
T34 |
16920 |
16470 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_io_meas_ctrl_en_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: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T1 T2 T3
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
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: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: 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: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T1 T2 T3
135 1/1 txn_bits_q <= '0;
Tests: T1 T2 T3
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: 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_io_meas_ctrl_en_cdc
| Total | Covered | Percent |
Conditions | 14 | 12 | 85.71 |
Logical | 14 | 12 | 85.71 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T1,T2,T3 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
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 | T4,T5,T6 |
0 | 1 | Covered | T7,T8,T9 |
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 | T4,T5,T6 |
1 | 0 | Not Covered | |
1 | 1 | Covered | T7,T8,T9 |
Branch Coverage for Instance : tb.dut.u_reg.u_io_meas_ctrl_en_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_io_meas_ctrl_en_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
45019 |
0 |
0 |
T1 |
27978 |
46 |
0 |
0 |
T2 |
0 |
48 |
0 |
0 |
T3 |
0 |
52 |
0 |
0 |
T10 |
0 |
29 |
0 |
0 |
T27 |
0 |
42 |
0 |
0 |
T39 |
0 |
11 |
0 |
0 |
T44 |
0 |
38 |
0 |
0 |
T45 |
0 |
27 |
0 |
0 |
T47 |
0 |
72 |
0 |
0 |
T48 |
0 |
6 |
0 |
0 |
T49 |
1457 |
0 |
0 |
0 |
T50 |
1111 |
0 |
0 |
0 |
T51 |
2316 |
0 |
0 |
0 |
T52 |
1259 |
0 |
0 |
0 |
T53 |
2234 |
0 |
0 |
0 |
T54 |
9524 |
0 |
0 |
0 |
T55 |
757 |
0 |
0 |
0 |
T56 |
1568 |
0 |
0 |
0 |
T57 |
978 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
93016148 |
88992250 |
0 |
0 |
T4 |
1698 |
1522 |
0 |
0 |
T5 |
2055 |
1920 |
0 |
0 |
T6 |
2314 |
2151 |
0 |
0 |
T28 |
2002 |
1922 |
0 |
0 |
T29 |
1508 |
1277 |
0 |
0 |
T30 |
1467 |
1305 |
0 |
0 |
T31 |
8771 |
8540 |
0 |
0 |
T32 |
2137 |
1947 |
0 |
0 |
T33 |
6017 |
5855 |
0 |
0 |
T34 |
9560 |
9302 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
12917 |
0 |
0 |
T1 |
27978 |
10 |
0 |
0 |
T2 |
0 |
14 |
0 |
0 |
T3 |
0 |
10 |
0 |
0 |
T10 |
0 |
12 |
0 |
0 |
T27 |
0 |
12 |
0 |
0 |
T39 |
0 |
4 |
0 |
0 |
T44 |
0 |
12 |
0 |
0 |
T45 |
0 |
8 |
0 |
0 |
T47 |
0 |
28 |
0 |
0 |
T48 |
0 |
2 |
0 |
0 |
T49 |
1457 |
0 |
0 |
0 |
T50 |
1111 |
0 |
0 |
0 |
T51 |
2316 |
0 |
0 |
0 |
T52 |
1259 |
0 |
0 |
0 |
T53 |
2234 |
0 |
0 |
0 |
T54 |
9524 |
0 |
0 |
0 |
T55 |
757 |
0 |
0 |
0 |
T56 |
1568 |
0 |
0 |
0 |
T57 |
978 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
38268216 |
0 |
0 |
T4 |
884 |
792 |
0 |
0 |
T5 |
2035 |
1901 |
0 |
0 |
T6 |
2314 |
2151 |
0 |
0 |
T28 |
2085 |
2001 |
0 |
0 |
T29 |
1524 |
1290 |
0 |
0 |
T30 |
1482 |
1318 |
0 |
0 |
T31 |
2102 |
2047 |
0 |
0 |
T32 |
2137 |
1947 |
0 |
0 |
T33 |
2381 |
2317 |
0 |
0 |
T34 |
1692 |
1647 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_io_div2_meas_ctrl_en_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: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T1 T2 T3
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
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: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: 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: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T1 T2 T3
135 1/1 txn_bits_q <= '0;
Tests: T1 T2 T3
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: 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_io_div2_meas_ctrl_en_cdc
| Total | Covered | Percent |
Conditions | 14 | 12 | 85.71 |
Logical | 14 | 12 | 85.71 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T1,T2,T3 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
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 | T4,T5,T6 |
0 | 1 | Covered | T7,T8,T9 |
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 | T4,T5,T6 |
1 | 0 | Not Covered | |
1 | 1 | Covered | T7,T8,T9 |
Branch Coverage for Instance : tb.dut.u_reg.u_io_div2_meas_ctrl_en_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_io_div2_meas_ctrl_en_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
63206 |
0 |
0 |
T1 |
27978 |
79 |
0 |
0 |
T2 |
0 |
67 |
0 |
0 |
T3 |
0 |
86 |
0 |
0 |
T10 |
0 |
39 |
0 |
0 |
T27 |
0 |
61 |
0 |
0 |
T39 |
0 |
15 |
0 |
0 |
T44 |
0 |
50 |
0 |
0 |
T45 |
0 |
38 |
0 |
0 |
T47 |
0 |
100 |
0 |
0 |
T48 |
0 |
8 |
0 |
0 |
T49 |
1457 |
0 |
0 |
0 |
T50 |
1111 |
0 |
0 |
0 |
T51 |
2316 |
0 |
0 |
0 |
T52 |
1259 |
0 |
0 |
0 |
T53 |
2234 |
0 |
0 |
0 |
T54 |
9524 |
0 |
0 |
0 |
T55 |
757 |
0 |
0 |
0 |
T56 |
1568 |
0 |
0 |
0 |
T57 |
978 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
45761112 |
44776047 |
0 |
0 |
T4 |
813 |
792 |
0 |
0 |
T5 |
981 |
960 |
0 |
0 |
T6 |
1188 |
1167 |
0 |
0 |
T28 |
1125 |
1104 |
0 |
0 |
T29 |
700 |
638 |
0 |
0 |
T30 |
756 |
687 |
0 |
0 |
T31 |
4318 |
4270 |
0 |
0 |
T32 |
1001 |
973 |
0 |
0 |
T33 |
2941 |
2927 |
0 |
0 |
T34 |
4720 |
4651 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
12917 |
0 |
0 |
T1 |
27978 |
10 |
0 |
0 |
T2 |
0 |
14 |
0 |
0 |
T3 |
0 |
10 |
0 |
0 |
T10 |
0 |
12 |
0 |
0 |
T27 |
0 |
12 |
0 |
0 |
T39 |
0 |
4 |
0 |
0 |
T44 |
0 |
12 |
0 |
0 |
T45 |
0 |
8 |
0 |
0 |
T47 |
0 |
28 |
0 |
0 |
T48 |
0 |
2 |
0 |
0 |
T49 |
1457 |
0 |
0 |
0 |
T50 |
1111 |
0 |
0 |
0 |
T51 |
2316 |
0 |
0 |
0 |
T52 |
1259 |
0 |
0 |
0 |
T53 |
2234 |
0 |
0 |
0 |
T54 |
9524 |
0 |
0 |
0 |
T55 |
757 |
0 |
0 |
0 |
T56 |
1568 |
0 |
0 |
0 |
T57 |
978 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
38268216 |
0 |
0 |
T4 |
884 |
792 |
0 |
0 |
T5 |
2035 |
1901 |
0 |
0 |
T6 |
2314 |
2151 |
0 |
0 |
T28 |
2085 |
2001 |
0 |
0 |
T29 |
1524 |
1290 |
0 |
0 |
T30 |
1482 |
1318 |
0 |
0 |
T31 |
2102 |
2047 |
0 |
0 |
T32 |
2137 |
1947 |
0 |
0 |
T33 |
2381 |
2317 |
0 |
0 |
T34 |
1692 |
1647 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_io_div4_meas_ctrl_en_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: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T1 T2 T3
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
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: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: 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: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T1 T2 T3
135 1/1 txn_bits_q <= '0;
Tests: T1 T2 T3
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: 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_io_div4_meas_ctrl_en_cdc
| Total | Covered | Percent |
Conditions | 14 | 12 | 85.71 |
Logical | 14 | 12 | 85.71 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T1,T2,T3 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
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 | T4,T5,T6 |
0 | 1 | Covered | T7,T8,T9 |
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 | T4,T5,T6 |
1 | 0 | Not Covered | |
1 | 1 | Covered | T7,T8,T9 |
Branch Coverage for Instance : tb.dut.u_reg.u_io_div4_meas_ctrl_en_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_io_div4_meas_ctrl_en_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
99640 |
0 |
0 |
T1 |
27978 |
140 |
0 |
0 |
T2 |
0 |
103 |
0 |
0 |
T3 |
0 |
146 |
0 |
0 |
T10 |
0 |
58 |
0 |
0 |
T27 |
0 |
99 |
0 |
0 |
T39 |
0 |
22 |
0 |
0 |
T44 |
0 |
76 |
0 |
0 |
T45 |
0 |
61 |
0 |
0 |
T47 |
0 |
144 |
0 |
0 |
T48 |
0 |
13 |
0 |
0 |
T49 |
1457 |
0 |
0 |
0 |
T50 |
1111 |
0 |
0 |
0 |
T51 |
2316 |
0 |
0 |
0 |
T52 |
1259 |
0 |
0 |
0 |
T53 |
2234 |
0 |
0 |
0 |
T54 |
9524 |
0 |
0 |
0 |
T55 |
757 |
0 |
0 |
0 |
T56 |
1568 |
0 |
0 |
0 |
T57 |
978 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
22880144 |
22387721 |
0 |
0 |
T4 |
407 |
397 |
0 |
0 |
T5 |
490 |
480 |
0 |
0 |
T6 |
593 |
582 |
0 |
0 |
T28 |
562 |
552 |
0 |
0 |
T29 |
350 |
319 |
0 |
0 |
T30 |
377 |
343 |
0 |
0 |
T31 |
2159 |
2135 |
0 |
0 |
T32 |
501 |
487 |
0 |
0 |
T33 |
1471 |
1464 |
0 |
0 |
T34 |
2360 |
2326 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
12917 |
0 |
0 |
T1 |
27978 |
10 |
0 |
0 |
T2 |
0 |
14 |
0 |
0 |
T3 |
0 |
10 |
0 |
0 |
T10 |
0 |
12 |
0 |
0 |
T27 |
0 |
12 |
0 |
0 |
T39 |
0 |
4 |
0 |
0 |
T44 |
0 |
12 |
0 |
0 |
T45 |
0 |
8 |
0 |
0 |
T47 |
0 |
28 |
0 |
0 |
T48 |
0 |
2 |
0 |
0 |
T49 |
1457 |
0 |
0 |
0 |
T50 |
1111 |
0 |
0 |
0 |
T51 |
2316 |
0 |
0 |
0 |
T52 |
1259 |
0 |
0 |
0 |
T53 |
2234 |
0 |
0 |
0 |
T54 |
9524 |
0 |
0 |
0 |
T55 |
757 |
0 |
0 |
0 |
T56 |
1568 |
0 |
0 |
0 |
T57 |
978 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
38268216 |
0 |
0 |
T4 |
884 |
792 |
0 |
0 |
T5 |
2035 |
1901 |
0 |
0 |
T6 |
2314 |
2151 |
0 |
0 |
T28 |
2085 |
2001 |
0 |
0 |
T29 |
1524 |
1290 |
0 |
0 |
T30 |
1482 |
1318 |
0 |
0 |
T31 |
2102 |
2047 |
0 |
0 |
T32 |
2137 |
1947 |
0 |
0 |
T33 |
2381 |
2317 |
0 |
0 |
T34 |
1692 |
1647 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_main_meas_ctrl_en_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: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T1 T2 T3
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
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: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: 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: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T1 T2 T3
135 1/1 txn_bits_q <= '0;
Tests: T1 T2 T3
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: 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_main_meas_ctrl_en_cdc
| Total | Covered | Percent |
Conditions | 14 | 12 | 85.71 |
Logical | 14 | 12 | 85.71 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T1,T2,T3 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
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 | T4,T5,T6 |
0 | 1 | Covered | T7,T8,T9 |
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 | T4,T5,T6 |
1 | 0 | Not Covered | |
1 | 1 | Covered | T7,T8,T9 |
Branch Coverage for Instance : tb.dut.u_reg.u_main_meas_ctrl_en_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_main_meas_ctrl_en_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
43858 |
0 |
0 |
T1 |
27978 |
45 |
0 |
0 |
T2 |
0 |
47 |
0 |
0 |
T3 |
0 |
52 |
0 |
0 |
T10 |
0 |
27 |
0 |
0 |
T27 |
0 |
42 |
0 |
0 |
T39 |
0 |
11 |
0 |
0 |
T44 |
0 |
37 |
0 |
0 |
T45 |
0 |
27 |
0 |
0 |
T47 |
0 |
72 |
0 |
0 |
T48 |
0 |
5 |
0 |
0 |
T49 |
1457 |
0 |
0 |
0 |
T50 |
1111 |
0 |
0 |
0 |
T51 |
2316 |
0 |
0 |
0 |
T52 |
1259 |
0 |
0 |
0 |
T53 |
2234 |
0 |
0 |
0 |
T54 |
9524 |
0 |
0 |
0 |
T55 |
757 |
0 |
0 |
0 |
T56 |
1568 |
0 |
0 |
0 |
T57 |
978 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
102625272 |
98339472 |
0 |
0 |
T4 |
1768 |
1585 |
0 |
0 |
T5 |
2141 |
2001 |
0 |
0 |
T6 |
2411 |
2242 |
0 |
0 |
T28 |
2085 |
2001 |
0 |
0 |
T29 |
1562 |
1321 |
0 |
0 |
T30 |
1528 |
1359 |
0 |
0 |
T31 |
9137 |
8897 |
0 |
0 |
T32 |
2226 |
2029 |
0 |
0 |
T33 |
6267 |
6098 |
0 |
0 |
T34 |
9958 |
9689 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
12917 |
0 |
0 |
T1 |
27978 |
10 |
0 |
0 |
T2 |
0 |
14 |
0 |
0 |
T3 |
0 |
10 |
0 |
0 |
T10 |
0 |
12 |
0 |
0 |
T27 |
0 |
12 |
0 |
0 |
T39 |
0 |
4 |
0 |
0 |
T44 |
0 |
12 |
0 |
0 |
T45 |
0 |
8 |
0 |
0 |
T47 |
0 |
28 |
0 |
0 |
T48 |
0 |
2 |
0 |
0 |
T49 |
1457 |
0 |
0 |
0 |
T50 |
1111 |
0 |
0 |
0 |
T51 |
2316 |
0 |
0 |
0 |
T52 |
1259 |
0 |
0 |
0 |
T53 |
2234 |
0 |
0 |
0 |
T54 |
9524 |
0 |
0 |
0 |
T55 |
757 |
0 |
0 |
0 |
T56 |
1568 |
0 |
0 |
0 |
T57 |
978 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
38268216 |
0 |
0 |
T4 |
884 |
792 |
0 |
0 |
T5 |
2035 |
1901 |
0 |
0 |
T6 |
2314 |
2151 |
0 |
0 |
T28 |
2085 |
2001 |
0 |
0 |
T29 |
1524 |
1290 |
0 |
0 |
T30 |
1482 |
1318 |
0 |
0 |
T31 |
2102 |
2047 |
0 |
0 |
T32 |
2137 |
1947 |
0 |
0 |
T33 |
2381 |
2317 |
0 |
0 |
T34 |
1692 |
1647 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_usb_meas_ctrl_en_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: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T1 T2 T3
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
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: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: 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: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T1 T2 T3
135 1/1 txn_bits_q <= '0;
Tests: T1 T2 T3
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: 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_usb_meas_ctrl_en_cdc
| Total | Covered | Percent |
Conditions | 14 | 12 | 85.71 |
Logical | 14 | 12 | 85.71 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Unreachable | |
1 | 0 | Covered | T1,T2,T3 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
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 | T4,T5,T6 |
0 | 1 | Covered | T7,T8,T9 |
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 | T4,T5,T6 |
1 | 0 | Not Covered | |
1 | 1 | Covered | T7,T8,T9 |
Branch Coverage for Instance : tb.dut.u_reg.u_usb_meas_ctrl_en_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_usb_meas_ctrl_en_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
61974 |
0 |
0 |
T1 |
27978 |
46 |
0 |
0 |
T2 |
0 |
41 |
0 |
0 |
T3 |
0 |
85 |
0 |
0 |
T10 |
0 |
32 |
0 |
0 |
T27 |
0 |
61 |
0 |
0 |
T39 |
0 |
15 |
0 |
0 |
T44 |
0 |
52 |
0 |
0 |
T45 |
0 |
38 |
0 |
0 |
T47 |
0 |
100 |
0 |
0 |
T48 |
0 |
8 |
0 |
0 |
T49 |
1457 |
0 |
0 |
0 |
T50 |
1111 |
0 |
0 |
0 |
T51 |
2316 |
0 |
0 |
0 |
T52 |
1259 |
0 |
0 |
0 |
T53 |
2234 |
0 |
0 |
0 |
T54 |
9524 |
0 |
0 |
0 |
T55 |
757 |
0 |
0 |
0 |
T56 |
1568 |
0 |
0 |
0 |
T57 |
978 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
49222570 |
47175592 |
0 |
0 |
T4 |
849 |
761 |
0 |
0 |
T5 |
1027 |
960 |
0 |
0 |
T6 |
1157 |
1076 |
0 |
0 |
T28 |
1001 |
961 |
0 |
0 |
T29 |
753 |
638 |
0 |
0 |
T30 |
733 |
652 |
0 |
0 |
T31 |
4385 |
4270 |
0 |
0 |
T32 |
1069 |
974 |
0 |
0 |
T33 |
3009 |
2928 |
0 |
0 |
T34 |
4780 |
4651 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
12570 |
0 |
0 |
T1 |
27978 |
5 |
0 |
0 |
T2 |
0 |
7 |
0 |
0 |
T3 |
0 |
10 |
0 |
0 |
T10 |
0 |
9 |
0 |
0 |
T27 |
0 |
12 |
0 |
0 |
T39 |
0 |
4 |
0 |
0 |
T44 |
0 |
12 |
0 |
0 |
T45 |
0 |
8 |
0 |
0 |
T47 |
0 |
28 |
0 |
0 |
T48 |
0 |
2 |
0 |
0 |
T49 |
1457 |
0 |
0 |
0 |
T50 |
1111 |
0 |
0 |
0 |
T51 |
2316 |
0 |
0 |
0 |
T52 |
1259 |
0 |
0 |
0 |
T53 |
2234 |
0 |
0 |
0 |
T54 |
9524 |
0 |
0 |
0 |
T55 |
757 |
0 |
0 |
0 |
T56 |
1568 |
0 |
0 |
0 |
T57 |
978 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
38268216 |
0 |
0 |
T4 |
884 |
792 |
0 |
0 |
T5 |
2035 |
1901 |
0 |
0 |
T6 |
2314 |
2151 |
0 |
0 |
T28 |
2085 |
2001 |
0 |
0 |
T29 |
1524 |
1290 |
0 |
0 |
T30 |
1482 |
1318 |
0 |
0 |
T31 |
2102 |
2047 |
0 |
0 |
T32 |
2137 |
1947 |
0 |
0 |
T33 |
2381 |
2317 |
0 |
0 |
T34 |
1692 |
1647 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_io_meas_ctrl_shadowed_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: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T1 T2 T3
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
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: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: 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: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T1 T2 T3
135 1/1 txn_bits_q <= '0;
Tests: T1 T2 T3
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: 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_io_meas_ctrl_shadowed_cdc
| Total | Covered | Percent |
Conditions | 12 | 11 | 91.67 |
Logical | 12 | 11 | 91.67 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Covered | T1,T2,T10 |
1 | 0 | Covered | T1,T2,T3 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
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 | T4,T5,T6 |
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 | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_io_meas_ctrl_shadowed_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_io_meas_ctrl_shadowed_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
65846 |
0 |
0 |
T1 |
27978 |
99 |
0 |
0 |
T2 |
0 |
91 |
0 |
0 |
T3 |
0 |
54 |
0 |
0 |
T10 |
0 |
63 |
0 |
0 |
T27 |
0 |
42 |
0 |
0 |
T39 |
0 |
11 |
0 |
0 |
T44 |
0 |
36 |
0 |
0 |
T45 |
0 |
28 |
0 |
0 |
T47 |
0 |
72 |
0 |
0 |
T48 |
0 |
6 |
0 |
0 |
T49 |
1457 |
0 |
0 |
0 |
T50 |
1111 |
0 |
0 |
0 |
T51 |
2316 |
0 |
0 |
0 |
T52 |
1259 |
0 |
0 |
0 |
T53 |
2234 |
0 |
0 |
0 |
T54 |
9524 |
0 |
0 |
0 |
T55 |
757 |
0 |
0 |
0 |
T56 |
1568 |
0 |
0 |
0 |
T57 |
978 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
93016148 |
88992250 |
0 |
0 |
T4 |
1698 |
1522 |
0 |
0 |
T5 |
2055 |
1920 |
0 |
0 |
T6 |
2314 |
2151 |
0 |
0 |
T28 |
2002 |
1922 |
0 |
0 |
T29 |
1508 |
1277 |
0 |
0 |
T30 |
1467 |
1305 |
0 |
0 |
T31 |
8771 |
8540 |
0 |
0 |
T32 |
2137 |
1947 |
0 |
0 |
T33 |
6017 |
5855 |
0 |
0 |
T34 |
9560 |
9302 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
18640 |
0 |
0 |
T1 |
27978 |
20 |
0 |
0 |
T2 |
0 |
28 |
0 |
0 |
T3 |
0 |
10 |
0 |
0 |
T10 |
0 |
24 |
0 |
0 |
T27 |
0 |
12 |
0 |
0 |
T39 |
0 |
4 |
0 |
0 |
T44 |
0 |
12 |
0 |
0 |
T45 |
0 |
8 |
0 |
0 |
T47 |
0 |
28 |
0 |
0 |
T48 |
0 |
2 |
0 |
0 |
T49 |
1457 |
0 |
0 |
0 |
T50 |
1111 |
0 |
0 |
0 |
T51 |
2316 |
0 |
0 |
0 |
T52 |
1259 |
0 |
0 |
0 |
T53 |
2234 |
0 |
0 |
0 |
T54 |
9524 |
0 |
0 |
0 |
T55 |
757 |
0 |
0 |
0 |
T56 |
1568 |
0 |
0 |
0 |
T57 |
978 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
38268216 |
0 |
0 |
T4 |
884 |
792 |
0 |
0 |
T5 |
2035 |
1901 |
0 |
0 |
T6 |
2314 |
2151 |
0 |
0 |
T28 |
2085 |
2001 |
0 |
0 |
T29 |
1524 |
1290 |
0 |
0 |
T30 |
1482 |
1318 |
0 |
0 |
T31 |
2102 |
2047 |
0 |
0 |
T32 |
2137 |
1947 |
0 |
0 |
T33 |
2381 |
2317 |
0 |
0 |
T34 |
1692 |
1647 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_io_div2_meas_ctrl_shadowed_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: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T1 T2 T3
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
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: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: 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: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T1 T2 T3
135 1/1 txn_bits_q <= '0;
Tests: T1 T2 T3
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: 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_io_div2_meas_ctrl_shadowed_cdc
| Total | Covered | Percent |
Conditions | 12 | 11 | 91.67 |
Logical | 12 | 11 | 91.67 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Covered | T1,T2,T10 |
1 | 0 | Covered | T1,T2,T3 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
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 | T4,T5,T6 |
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 | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_io_div2_meas_ctrl_shadowed_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_io_div2_meas_ctrl_shadowed_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
93708 |
0 |
0 |
T1 |
27978 |
157 |
0 |
0 |
T2 |
0 |
125 |
0 |
0 |
T3 |
0 |
83 |
0 |
0 |
T10 |
0 |
87 |
0 |
0 |
T27 |
0 |
61 |
0 |
0 |
T39 |
0 |
15 |
0 |
0 |
T44 |
0 |
51 |
0 |
0 |
T45 |
0 |
38 |
0 |
0 |
T47 |
0 |
100 |
0 |
0 |
T48 |
0 |
8 |
0 |
0 |
T49 |
1457 |
0 |
0 |
0 |
T50 |
1111 |
0 |
0 |
0 |
T51 |
2316 |
0 |
0 |
0 |
T52 |
1259 |
0 |
0 |
0 |
T53 |
2234 |
0 |
0 |
0 |
T54 |
9524 |
0 |
0 |
0 |
T55 |
757 |
0 |
0 |
0 |
T56 |
1568 |
0 |
0 |
0 |
T57 |
978 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
45761112 |
44776047 |
0 |
0 |
T4 |
813 |
792 |
0 |
0 |
T5 |
981 |
960 |
0 |
0 |
T6 |
1188 |
1167 |
0 |
0 |
T28 |
1125 |
1104 |
0 |
0 |
T29 |
700 |
638 |
0 |
0 |
T30 |
756 |
687 |
0 |
0 |
T31 |
4318 |
4270 |
0 |
0 |
T32 |
1001 |
973 |
0 |
0 |
T33 |
2941 |
2927 |
0 |
0 |
T34 |
4720 |
4651 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
18766 |
0 |
0 |
T1 |
27978 |
20 |
0 |
0 |
T2 |
0 |
28 |
0 |
0 |
T3 |
0 |
10 |
0 |
0 |
T10 |
0 |
24 |
0 |
0 |
T27 |
0 |
12 |
0 |
0 |
T39 |
0 |
4 |
0 |
0 |
T44 |
0 |
12 |
0 |
0 |
T45 |
0 |
8 |
0 |
0 |
T47 |
0 |
28 |
0 |
0 |
T48 |
0 |
2 |
0 |
0 |
T49 |
1457 |
0 |
0 |
0 |
T50 |
1111 |
0 |
0 |
0 |
T51 |
2316 |
0 |
0 |
0 |
T52 |
1259 |
0 |
0 |
0 |
T53 |
2234 |
0 |
0 |
0 |
T54 |
9524 |
0 |
0 |
0 |
T55 |
757 |
0 |
0 |
0 |
T56 |
1568 |
0 |
0 |
0 |
T57 |
978 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
38268216 |
0 |
0 |
T4 |
884 |
792 |
0 |
0 |
T5 |
2035 |
1901 |
0 |
0 |
T6 |
2314 |
2151 |
0 |
0 |
T28 |
2085 |
2001 |
0 |
0 |
T29 |
1524 |
1290 |
0 |
0 |
T30 |
1482 |
1318 |
0 |
0 |
T31 |
2102 |
2047 |
0 |
0 |
T32 |
2137 |
1947 |
0 |
0 |
T33 |
2381 |
2317 |
0 |
0 |
T34 |
1692 |
1647 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_io_div4_meas_ctrl_shadowed_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: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T1 T2 T3
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
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: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: 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: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T1 T2 T3
135 1/1 txn_bits_q <= '0;
Tests: T1 T2 T3
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: 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_io_div4_meas_ctrl_shadowed_cdc
| Total | Covered | Percent |
Conditions | 12 | 11 | 91.67 |
Logical | 12 | 11 | 91.67 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Covered | T1,T2,T10 |
1 | 0 | Covered | T1,T2,T3 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
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 | T4,T5,T6 |
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 | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_io_div4_meas_ctrl_shadowed_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_io_div4_meas_ctrl_shadowed_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
148496 |
0 |
0 |
T1 |
27978 |
270 |
0 |
0 |
T2 |
0 |
190 |
0 |
0 |
T3 |
0 |
158 |
0 |
0 |
T10 |
0 |
127 |
0 |
0 |
T27 |
0 |
98 |
0 |
0 |
T39 |
0 |
22 |
0 |
0 |
T44 |
0 |
81 |
0 |
0 |
T45 |
0 |
60 |
0 |
0 |
T47 |
0 |
144 |
0 |
0 |
T48 |
0 |
14 |
0 |
0 |
T49 |
1457 |
0 |
0 |
0 |
T50 |
1111 |
0 |
0 |
0 |
T51 |
2316 |
0 |
0 |
0 |
T52 |
1259 |
0 |
0 |
0 |
T53 |
2234 |
0 |
0 |
0 |
T54 |
9524 |
0 |
0 |
0 |
T55 |
757 |
0 |
0 |
0 |
T56 |
1568 |
0 |
0 |
0 |
T57 |
978 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
22880144 |
22387721 |
0 |
0 |
T4 |
407 |
397 |
0 |
0 |
T5 |
490 |
480 |
0 |
0 |
T6 |
593 |
582 |
0 |
0 |
T28 |
562 |
552 |
0 |
0 |
T29 |
350 |
319 |
0 |
0 |
T30 |
377 |
343 |
0 |
0 |
T31 |
2159 |
2135 |
0 |
0 |
T32 |
501 |
487 |
0 |
0 |
T33 |
1471 |
1464 |
0 |
0 |
T34 |
2360 |
2326 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
18742 |
0 |
0 |
T1 |
27978 |
20 |
0 |
0 |
T2 |
0 |
28 |
0 |
0 |
T3 |
0 |
10 |
0 |
0 |
T10 |
0 |
24 |
0 |
0 |
T27 |
0 |
12 |
0 |
0 |
T39 |
0 |
4 |
0 |
0 |
T44 |
0 |
12 |
0 |
0 |
T45 |
0 |
8 |
0 |
0 |
T47 |
0 |
28 |
0 |
0 |
T48 |
0 |
2 |
0 |
0 |
T49 |
1457 |
0 |
0 |
0 |
T50 |
1111 |
0 |
0 |
0 |
T51 |
2316 |
0 |
0 |
0 |
T52 |
1259 |
0 |
0 |
0 |
T53 |
2234 |
0 |
0 |
0 |
T54 |
9524 |
0 |
0 |
0 |
T55 |
757 |
0 |
0 |
0 |
T56 |
1568 |
0 |
0 |
0 |
T57 |
978 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
38268216 |
0 |
0 |
T4 |
884 |
792 |
0 |
0 |
T5 |
2035 |
1901 |
0 |
0 |
T6 |
2314 |
2151 |
0 |
0 |
T28 |
2085 |
2001 |
0 |
0 |
T29 |
1524 |
1290 |
0 |
0 |
T30 |
1482 |
1318 |
0 |
0 |
T31 |
2102 |
2047 |
0 |
0 |
T32 |
2137 |
1947 |
0 |
0 |
T33 |
2381 |
2317 |
0 |
0 |
T34 |
1692 |
1647 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_main_meas_ctrl_shadowed_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: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T1 T2 T3
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
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: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: 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: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T1 T2 T3
135 1/1 txn_bits_q <= '0;
Tests: T1 T2 T3
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: 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_main_meas_ctrl_shadowed_cdc
| Total | Covered | Percent |
Conditions | 12 | 11 | 91.67 |
Logical | 12 | 11 | 91.67 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Covered | T1,T2,T10 |
1 | 0 | Covered | T1,T2,T3 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
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 | T4,T5,T6 |
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 | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_main_meas_ctrl_shadowed_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_main_meas_ctrl_shadowed_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
64578 |
0 |
0 |
T1 |
27978 |
96 |
0 |
0 |
T2 |
0 |
90 |
0 |
0 |
T3 |
0 |
51 |
0 |
0 |
T10 |
0 |
62 |
0 |
0 |
T27 |
0 |
42 |
0 |
0 |
T39 |
0 |
11 |
0 |
0 |
T44 |
0 |
37 |
0 |
0 |
T45 |
0 |
27 |
0 |
0 |
T47 |
0 |
72 |
0 |
0 |
T48 |
0 |
6 |
0 |
0 |
T49 |
1457 |
0 |
0 |
0 |
T50 |
1111 |
0 |
0 |
0 |
T51 |
2316 |
0 |
0 |
0 |
T52 |
1259 |
0 |
0 |
0 |
T53 |
2234 |
0 |
0 |
0 |
T54 |
9524 |
0 |
0 |
0 |
T55 |
757 |
0 |
0 |
0 |
T56 |
1568 |
0 |
0 |
0 |
T57 |
978 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
102625272 |
98339472 |
0 |
0 |
T4 |
1768 |
1585 |
0 |
0 |
T5 |
2141 |
2001 |
0 |
0 |
T6 |
2411 |
2242 |
0 |
0 |
T28 |
2085 |
2001 |
0 |
0 |
T29 |
1562 |
1321 |
0 |
0 |
T30 |
1528 |
1359 |
0 |
0 |
T31 |
9137 |
8897 |
0 |
0 |
T32 |
2226 |
2029 |
0 |
0 |
T33 |
6267 |
6098 |
0 |
0 |
T34 |
9958 |
9689 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
18689 |
0 |
0 |
T1 |
27978 |
20 |
0 |
0 |
T2 |
0 |
28 |
0 |
0 |
T3 |
0 |
10 |
0 |
0 |
T10 |
0 |
24 |
0 |
0 |
T27 |
0 |
12 |
0 |
0 |
T39 |
0 |
4 |
0 |
0 |
T44 |
0 |
12 |
0 |
0 |
T45 |
0 |
8 |
0 |
0 |
T47 |
0 |
28 |
0 |
0 |
T48 |
0 |
2 |
0 |
0 |
T49 |
1457 |
0 |
0 |
0 |
T50 |
1111 |
0 |
0 |
0 |
T51 |
2316 |
0 |
0 |
0 |
T52 |
1259 |
0 |
0 |
0 |
T53 |
2234 |
0 |
0 |
0 |
T54 |
9524 |
0 |
0 |
0 |
T55 |
757 |
0 |
0 |
0 |
T56 |
1568 |
0 |
0 |
0 |
T57 |
978 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
38268216 |
0 |
0 |
T4 |
884 |
792 |
0 |
0 |
T5 |
2035 |
1901 |
0 |
0 |
T6 |
2314 |
2151 |
0 |
0 |
T28 |
2085 |
2001 |
0 |
0 |
T29 |
1524 |
1290 |
0 |
0 |
T30 |
1482 |
1318 |
0 |
0 |
T31 |
2102 |
2047 |
0 |
0 |
T32 |
2137 |
1947 |
0 |
0 |
T33 |
2381 |
2317 |
0 |
0 |
T34 |
1692 |
1647 |
0 |
0 |
Line Coverage for Instance : tb.dut.u_reg.u_usb_meas_ctrl_shadowed_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: T4 T5 T6
72 1/1 src_busy_q <= '0;
Tests: T4 T5 T6
73 1/1 end else if (src_req) begin
Tests: T4 T5 T6
74 1/1 src_busy_q <= 1'b1;
Tests: T1 T2 T3
75 1/1 end else if (src_ack) begin
Tests: T4 T5 T6
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: T4 T5 T6
116 1/1 src_q <= ResetVal;
Tests: T4 T5 T6
117 1/1 txn_bits_q <= '0;
Tests: T4 T5 T6
118 1/1 end else if (src_req) begin
Tests: T4 T5 T6
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 1/1 src_q <= src_wd_i & BitMask;
Tests: 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: T4 T5 T6
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 1/1 src_q <= dst_qs;
Tests: T1 T2 T3
135 1/1 txn_bits_q <= '0;
Tests: T1 T2 T3
136 end
MISSING_ELSE
137 end
138
139 // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140 // (decoded from address) is busy. So this creates a situation in the current design where
141 // src_req_i and busy can never be high at the same time.
142 // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143 // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144 // condition cannot be met.
145 // Thus we add an assertion here to ensure the condition is always satisfied.
146 `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147
148 // reserved bits are not used
149 logic unused_wd;
150 1/1 assign unused_wd = ^src_wd_i;
Tests: T4 T5 T6
151
152 // src_q is always updated in the clk_src domain.
153 // when performing an update to the destination domain, it is guaranteed
154 // to not change by protocol.
155 1/1 assign src_qs_o = src_q;
Tests: 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_usb_meas_ctrl_shadowed_cdc
| Total | Covered | Percent |
Conditions | 12 | 11 | 91.67 |
Logical | 12 | 11 | 91.67 |
Non-Logical | 0 | 0 | |
Event | 0 | 0 | |
LINE 65
EXPRESSION (src_we_i | src_re_i)
----1--- ----2---
-1- | -2- | Status | Tests |
0 | 0 | Covered | T4,T5,T6 |
0 | 1 | Covered | T1,T2,T10 |
1 | 0 | Covered | T1,T2,T3 |
LINE 109
EXPRESSION (src_busy_q & ((!src_ack)))
-----1---- ------2-----
-1- | -2- | Status | Tests |
0 | 1 | Covered | T4,T5,T6 |
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 | T4,T5,T6 |
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 | T4,T5,T6 |
1 | 0 | Unreachable | |
1 | 1 | Unreachable | |
Branch Coverage for Instance : tb.dut.u_reg.u_usb_meas_ctrl_shadowed_cdc
| Line No. | Total | Covered | Percent |
Branches |
|
8 |
8 |
100.00 |
IF |
71 |
4 |
4 |
100.00 |
IF |
115 |
4 |
4 |
100.00 |
71 if (!rst_src_ni) begin
-1-
72 src_busy_q <= '0;
==>
73 end else if (src_req) begin
-2-
74 src_busy_q <= 1'b1;
==>
75 end else if (src_ack) begin
-3-
76 src_busy_q <= 1'b0;
==>
77 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
115 if (!rst_src_ni) begin
-1-
116 src_q <= ResetVal;
==>
117 txn_bits_q <= '0;
118 end else if (src_req) begin
-2-
119 // See assertion below
120 // At the beginning of a software initiated transaction, the following
121 // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122 // change for the duration of the synchronization operation.
123 src_q <= src_wd_i & BitMask;
==>
124 txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125 end else if (src_busy_q && src_ack || src_update && !busy) begin
-3-
126 // sample data whenever a busy transaction finishes OR
127 // when an update pulse is seen.
128 // TODO: We should add a cover group to test different sync timings
129 // between src_ack and src_update. ie. there can be 3 scenarios:
130 // 1. update one cycle before ack
131 // 2. ack one cycle before update
132 // 3. update / ack on the same cycle
133 // During all 3 cases the read data should be correct
134 src_q <= dst_qs;
==>
135 txn_bits_q <= '0;
136 end
MISSING_ELSE
==>
Branches:
-1- | -2- | -3- | Status | Tests |
1 |
- |
- |
Covered |
T4,T5,T6 |
0 |
1 |
- |
Covered |
T1,T2,T3 |
0 |
0 |
1 |
Covered |
T1,T2,T3 |
0 |
0 |
0 |
Covered |
T4,T5,T6 |
Assert Coverage for Instance : tb.dut.u_reg.u_usb_meas_ctrl_shadowed_cdc
Assertion Details
BusySrcReqChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
93185 |
0 |
0 |
T1 |
27978 |
134 |
0 |
0 |
T2 |
0 |
123 |
0 |
0 |
T3 |
0 |
84 |
0 |
0 |
T10 |
0 |
87 |
0 |
0 |
T27 |
0 |
62 |
0 |
0 |
T39 |
0 |
15 |
0 |
0 |
T44 |
0 |
52 |
0 |
0 |
T45 |
0 |
40 |
0 |
0 |
T47 |
0 |
100 |
0 |
0 |
T48 |
0 |
8 |
0 |
0 |
T49 |
1457 |
0 |
0 |
0 |
T50 |
1111 |
0 |
0 |
0 |
T51 |
2316 |
0 |
0 |
0 |
T52 |
1259 |
0 |
0 |
0 |
T53 |
2234 |
0 |
0 |
0 |
T54 |
9524 |
0 |
0 |
0 |
T55 |
757 |
0 |
0 |
0 |
T56 |
1568 |
0 |
0 |
0 |
T57 |
978 |
0 |
0 |
0 |
DstReqKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
49222570 |
47175592 |
0 |
0 |
T4 |
849 |
761 |
0 |
0 |
T5 |
1027 |
960 |
0 |
0 |
T6 |
1157 |
1076 |
0 |
0 |
T28 |
1001 |
961 |
0 |
0 |
T29 |
753 |
638 |
0 |
0 |
T30 |
733 |
652 |
0 |
0 |
T31 |
4385 |
4270 |
0 |
0 |
T32 |
1069 |
974 |
0 |
0 |
T33 |
3009 |
2928 |
0 |
0 |
T34 |
4780 |
4651 |
0 |
0 |
SrcAckBusyChk_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
18509 |
0 |
0 |
T1 |
27978 |
15 |
0 |
0 |
T2 |
0 |
25 |
0 |
0 |
T3 |
0 |
10 |
0 |
0 |
T10 |
0 |
24 |
0 |
0 |
T27 |
0 |
12 |
0 |
0 |
T39 |
0 |
4 |
0 |
0 |
T44 |
0 |
12 |
0 |
0 |
T45 |
0 |
8 |
0 |
0 |
T47 |
0 |
28 |
0 |
0 |
T48 |
0 |
2 |
0 |
0 |
T49 |
1457 |
0 |
0 |
0 |
T50 |
1111 |
0 |
0 |
0 |
T51 |
2316 |
0 |
0 |
0 |
T52 |
1259 |
0 |
0 |
0 |
T53 |
2234 |
0 |
0 |
0 |
T54 |
9524 |
0 |
0 |
0 |
T55 |
757 |
0 |
0 |
0 |
T56 |
1568 |
0 |
0 |
0 |
T57 |
978 |
0 |
0 |
0 |
SrcBusyKnown_A
Name | Attempts | Real Successes | Failures | Incomplete |
Total |
40545146 |
38268216 |
0 |
0 |
T4 |
884 |
792 |
0 |
0 |
T5 |
2035 |
1901 |
0 |
0 |
T6 |
2314 |
2151 |
0 |
0 |
T28 |
2085 |
2001 |
0 |
0 |
T29 |
1524 |
1290 |
0 |
0 |
T30 |
1482 |
1318 |
0 |
0 |
T31 |
2102 |
2047 |
0 |
0 |
T32 |
2137 |
1947 |
0 |
0 |
T33 |
2381 |
2317 |
0 |
0 |
T34 |
1692 |
1647 |
0 |
0 |