Unified Coverage Report :: Module :: prim_reg_cdc

Module : prim_reg_cdc

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
96.67	100.00	86.67			100.00	100.00

Source File(s) :
/workspaces/repo/scratch/os_regression/clkmgr-sim-vcs/default/sim-vcs/../src/lowrisc_prim_subreg_0/rtl/prim_reg_cdc.sv

Module self-instances :

NAME	SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
tb.dut.u_reg.u_io_meas_ctrl_en_cdc	96.43	100.00	85.71			100.00	100.00
tb.dut.u_reg.u_io_div2_meas_ctrl_en_cdc	96.43	100.00	85.71			100.00	100.00
tb.dut.u_reg.u_io_div4_meas_ctrl_en_cdc	96.43	100.00	85.71			100.00	100.00
tb.dut.u_reg.u_main_meas_ctrl_en_cdc	96.43	100.00	85.71			100.00	100.00
tb.dut.u_reg.u_usb_meas_ctrl_en_cdc	96.43	100.00	85.71			100.00	100.00
tb.dut.u_reg.u_io_meas_ctrl_shadowed_cdc	97.92	100.00	91.67			100.00	100.00
tb.dut.u_reg.u_io_div2_meas_ctrl_shadowed_cdc	97.92	100.00	91.67			100.00	100.00
tb.dut.u_reg.u_io_div4_meas_ctrl_shadowed_cdc	97.92	100.00	91.67			100.00	100.00
tb.dut.u_reg.u_main_meas_ctrl_shadowed_cdc	97.92	100.00	91.67			100.00	100.00
tb.dut.u_reg.u_usb_meas_ctrl_shadowed_cdc	97.92	100.00	91.67			100.00	100.00

---

Module Instance : tb.dut.u_reg.u_io_meas_ctrl_en_cdc

Instance :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
96.43	100.00	85.71			100.00	100.00

Instance's subtree :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
89.66	96.24	80.88			91.53	90.00

Parent :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT	NAME
100.00	100.00	100.00			100.00	100.00	u_reg

Subtrees :

NAME	SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
u_arb	83.59	94.90	76.09			88.37	75.00
u_src_to_dst_req	100.00	100.00	100.00			100.00	100.00

---

Module Instance : tb.dut.u_reg.u_io_div2_meas_ctrl_en_cdc

Instance :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
96.43	100.00	85.71			100.00	100.00

Instance's subtree :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
89.66	96.24	80.88			91.53	90.00

Parent :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT	NAME
100.00	100.00	100.00			100.00	100.00	u_reg

Subtrees :

NAME	SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
u_arb	83.59	94.90	76.09			88.37	75.00
u_src_to_dst_req	100.00	100.00	100.00			100.00	100.00

---

Module Instance : tb.dut.u_reg.u_io_div4_meas_ctrl_en_cdc

Instance :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
96.43	100.00	85.71			100.00	100.00

Instance's subtree :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
92.36	97.74	86.76			94.92	90.00

Parent :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT	NAME
100.00	100.00	100.00			100.00	100.00	u_reg

Subtrees :

NAME	SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
u_arb	87.44	96.94	84.78			93.02	75.00
u_src_to_dst_req	100.00	100.00	100.00			100.00	100.00

---

Module Instance : tb.dut.u_reg.u_main_meas_ctrl_en_cdc

Instance :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
96.43	100.00	85.71			100.00	100.00

Instance's subtree :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
89.66	96.24	80.88			91.53	90.00

Parent :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT	NAME
100.00	100.00	100.00			100.00	100.00	u_reg

Subtrees :

NAME	SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
u_arb	83.59	94.90	76.09			88.37	75.00
u_src_to_dst_req	100.00	100.00	100.00			100.00	100.00

---

Module Instance : tb.dut.u_reg.u_usb_meas_ctrl_en_cdc

Instance :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
96.43	100.00	85.71			100.00	100.00

Instance's subtree :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
89.66	96.24	80.88			91.53	90.00

Parent :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT	NAME
100.00	100.00	100.00			100.00	100.00	u_reg

Subtrees :

NAME	SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
u_arb	83.59	94.90	76.09			88.37	75.00
u_src_to_dst_req	100.00	100.00	100.00			100.00	100.00

---

Module Instance : tb.dut.u_reg.u_io_meas_ctrl_shadowed_cdc

Instance :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
97.92	100.00	91.67			100.00	100.00

Instance's subtree :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
98.39	100.00	93.55			100.00	100.00

Parent :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT	NAME
100.00	100.00	100.00			100.00	100.00	u_reg

Subtrees :

NAME	SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
u_arb	97.73	100.00	90.91			100.00	100.00
u_src_to_dst_req	100.00	100.00	100.00			100.00	100.00

---

Module Instance : tb.dut.u_reg.u_io_div2_meas_ctrl_shadowed_cdc

Instance :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
97.92	100.00	91.67			100.00	100.00

Instance's subtree :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
98.39	100.00	93.55			100.00	100.00

Parent :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT	NAME
100.00	100.00	100.00			100.00	100.00	u_reg

Subtrees :

NAME	SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
u_arb	97.73	100.00	90.91			100.00	100.00
u_src_to_dst_req	100.00	100.00	100.00			100.00	100.00

---

Module Instance : tb.dut.u_reg.u_io_div4_meas_ctrl_shadowed_cdc

Instance :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
97.92	100.00	91.67			100.00	100.00

Instance's subtree :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
98.39	100.00	93.55			100.00	100.00

Parent :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT	NAME
100.00	100.00	100.00			100.00	100.00	u_reg

Subtrees :

NAME	SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
u_arb	97.73	100.00	90.91			100.00	100.00
u_src_to_dst_req	100.00	100.00	100.00			100.00	100.00

---

Module Instance : tb.dut.u_reg.u_main_meas_ctrl_shadowed_cdc

Instance :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
97.92	100.00	91.67			100.00	100.00

Instance's subtree :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
98.39	100.00	93.55			100.00	100.00

Parent :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT	NAME
100.00	100.00	100.00			100.00	100.00	u_reg

Subtrees :

NAME	SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
u_arb	97.73	100.00	90.91			100.00	100.00
u_src_to_dst_req	100.00	100.00	100.00			100.00	100.00

---

Module Instance : tb.dut.u_reg.u_usb_meas_ctrl_shadowed_cdc

Instance :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
97.92	100.00	91.67			100.00	100.00

Instance's subtree :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
98.39	100.00	93.55			100.00	100.00

Parent :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT	NAME
100.00	100.00	100.00			100.00	100.00	u_reg

Subtrees :

NAME	SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
u_arb	97.73	100.00	90.91			100.00	100.00
u_src_to_dst_req	100.00	100.00	100.00			100.00	100.00

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,T11,T27
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	T2,T9,T10
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	T2,T9,T10

---

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

	Total	Attempted	Percent	Succeeded/Matched	Percent
Assertions	4	4	100.00	4	100.00
Cover properties	0	0		0
Cover sequences	0	0		0
Total	4	4	100.00	4	100.00

---

Assertion Details

Name	Attempts	Real Successes	Failures	Incomplete
BusySrcReqChk_A	1720240140	1540769	0	0
DstReqKnown_A	2147483647	2147483647	0	0
SrcAckBusyChk_A	1720240140	280347	0	0
SrcBusyKnown_A	1720240140	1694114350	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	1720240140	1540769	0	0
T1	113600	636	0	0
T2	368270	853	0	0
T3	0	520	0	0
T9	0	238	0	0
T10	0	2625	0	0
T11	0	2603	0	0
T27	0	2383	0	0
T39	0	124	0	0
T40	0	228	0	0
T50	0	1852	0	0
T51	17080	0	0	0
T52	21460	0	0	0
T53	11030	0	0	0
T54	12940	0	0	0
T55	158410	0	0	0
T56	14210	0	0	0
T57	11100	0	0	0
T58	15940	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	2147483647	2147483647	0	0
T4	10788	9942	0	0
T5	60560	59674	0	0
T6	9170	8792	0	0
T28	8080	7094	0	0
T29	39456	38938	0	0
T30	19178	18112	0	0
T31	8330	7172	0	0
T32	14060	13022	0	0
T33	44600	43922	0	0
T34	13650	12866	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	1720240140	280347	0	0
T1	113600	176	0	0
T2	368270	260	0	0
T3	0	200	0	0
T9	0	80	0	0
T10	0	420	0	0
T11	0	313	0	0
T27	0	469	0	0
T39	0	40	0	0
T40	0	60	0	0
T50	0	340	0	0
T51	17080	0	0	0
T52	21460	0	0	0
T53	11030	0	0	0
T54	12940	0	0	0
T55	158410	0	0	0
T56	14210	0	0	0
T57	11100	0	0	0
T58	15940	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	1720240140	1694114350	0	0
T4	12670	11630	0	0
T5	12290	12050	0	0
T6	14460	13770	0	0
T28	13620	11940	0	0
T29	15010	14780	0	0
T30	14540	13590	0	0
T31	13400	11280	0	0
T32	22430	20600	0	0
T33	17560	17250	0	0
T34	21290	19890	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	T2,T9,T10
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	T2,T9,T10

---

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

	Total	Attempted	Percent	Succeeded/Matched	Percent
Assertions	4	4	100.00	4	100.00
Cover properties	0	0		0
Cover sequences	0	0		0
Total	4	4	100.00	4	100.00

---

Assertion Details

Name	Attempts	Real Successes	Failures	Incomplete
BusySrcReqChk_A	172024014	96162	0	0
DstReqKnown_A	477364878	473024093	0	0
SrcAckBusyChk_A	172024014	25420	0	0
SrcBusyKnown_A	172024014	169411435	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	96162	0	0
T1	11360	32	0	0
T2	36827	63	0	0
T3	0	51	0	0
T9	0	21	0	0
T10	0	174	0	0
T11	0	108	0	0
T27	0	115	0	0
T39	0	9	0	0
T40	0	18	0	0
T50	0	127	0	0
T51	1708	0	0	0
T52	2146	0	0	0
T53	1103	0	0	0
T54	1294	0	0	0
T55	15841	0	0	0
T56	1421	0	0	0
T57	1110	0	0	0
T58	1594	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	477364878	473024093	0	0
T4	1644	1510	0	0
T5	7874	7712	0	0
T6	1402	1336	0	0
T28	1238	1076	0	0
T29	6008	5915	0	0
T30	2907	2718	0	0
T31	1286	1083	0	0
T32	2154	1978	0	0
T33	6747	6626	0	0
T34	2044	1910	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	25420	0	0
T1	11360	12	0	0
T2	36827	26	0	0
T3	0	20	0	0
T9	0	8	0	0
T10	0	42	0	0
T11	0	22	0	0
T27	0	32	0	0
T39	0	4	0	0
T40	0	6	0	0
T50	0	34	0	0
T51	1708	0	0	0
T52	2146	0	0	0
T53	1103	0	0	0
T54	1294	0	0	0
T55	15841	0	0	0
T56	1421	0	0	0
T57	1110	0	0	0
T58	1594	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	169411435	0	0
T4	1267	1163	0	0
T5	1229	1205	0	0
T6	1446	1377	0	0
T28	1362	1194	0	0
T29	1501	1478	0	0
T30	1454	1359	0	0
T31	1340	1128	0	0
T32	2243	2060	0	0
T33	1756	1725	0	0
T34	2129	1989	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	T2,T9,T10
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	T2,T9,T10

---

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

	Total	Attempted	Percent	Succeeded/Matched	Percent
Assertions	4	4	100.00	4	100.00
Cover properties	0	0		0
Cover sequences	0	0		0
Total	4	4	100.00	4	100.00

---

Assertion Details

Name	Attempts	Real Successes	Failures	Incomplete
BusySrcReqChk_A	172024014	138525	0	0
DstReqKnown_A	237879213	236797354	0	0
SrcAckBusyChk_A	172024014	25420	0	0
SrcBusyKnown_A	172024014	169411435	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	138525	0	0
T1	11360	44	0	0
T2	36827	89	0	0
T3	0	51	0	0
T9	0	22	0	0
T10	0	265	0	0
T11	0	173	0	0
T27	0	168	0	0
T39	0	13	0	0
T40	0	23	0	0
T50	0	188	0	0
T51	1708	0	0	0
T52	2146	0	0	0
T53	1103	0	0	0
T54	1294	0	0	0
T55	15841	0	0	0
T56	1421	0	0	0
T57	1110	0	0	0
T58	1594	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	237879213	236797354	0	0
T4	810	755	0	0
T5	6844	6823	0	0
T6	682	668	0	0
T28	593	538	0	0
T29	2971	2957	0	0
T30	1466	1432	0	0
T31	598	557	0	0
T32	1037	989	0	0
T33	3435	3414	0	0
T34	1088	1054	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	25420	0	0
T1	11360	12	0	0
T2	36827	26	0	0
T3	0	20	0	0
T9	0	8	0	0
T10	0	42	0	0
T11	0	22	0	0
T27	0	32	0	0
T39	0	4	0	0
T40	0	6	0	0
T50	0	34	0	0
T51	1708	0	0	0
T52	2146	0	0	0
T53	1103	0	0	0
T54	1294	0	0	0
T55	15841	0	0	0
T56	1421	0	0	0
T57	1110	0	0	0
T58	1594	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	169411435	0	0
T4	1267	1163	0	0
T5	1229	1205	0	0
T6	1446	1377	0	0
T28	1362	1194	0	0
T29	1501	1478	0	0
T30	1454	1359	0	0
T31	1340	1128	0	0
T32	2243	2060	0	0
T33	1756	1725	0	0
T34	2129	1989	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	T2,T9,T10
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	T2,T9,T10

---

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

	Total	Attempted	Percent	Succeeded/Matched	Percent
Assertions	4	4	100.00	4	100.00
Cover properties	0	0		0
Cover sequences	0	0		0
Total	4	4	100.00	4	100.00

---

Assertion Details

Name	Attempts	Real Successes	Failures	Incomplete
BusySrcReqChk_A	172024014	224397	0	0
DstReqKnown_A	118938936	118398116	0	0
SrcAckBusyChk_A	172024014	25420	0	0
SrcBusyKnown_A	172024014	169411435	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	224397	0	0
T1	11360	62	0	0
T2	36827	125	0	0
T3	0	55	0	0
T9	0	30	0	0
T10	0	440	0	0
T11	0	312	0	0
T27	0	270	0	0
T39	0	18	0	0
T40	0	34	0	0
T50	0	301	0	0
T51	1708	0	0	0
T52	2146	0	0	0
T53	1103	0	0	0
T54	1294	0	0	0
T55	15841	0	0	0
T56	1421	0	0	0
T57	1110	0	0	0
T58	1594	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	118938936	118398116	0	0
T4	405	378	0	0
T5	3422	3412	0	0
T6	341	334	0	0
T28	296	269	0	0
T29	1486	1479	0	0
T30	733	716	0	0
T31	298	277	0	0
T32	519	495	0	0
T33	1717	1706	0	0
T34	542	525	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	25420	0	0
T1	11360	12	0	0
T2	36827	26	0	0
T3	0	20	0	0
T9	0	8	0	0
T10	0	42	0	0
T11	0	22	0	0
T27	0	32	0	0
T39	0	4	0	0
T40	0	6	0	0
T50	0	34	0	0
T51	1708	0	0	0
T52	2146	0	0	0
T53	1103	0	0	0
T54	1294	0	0	0
T55	15841	0	0	0
T56	1421	0	0	0
T57	1110	0	0	0
T58	1594	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	169411435	0	0
T4	1267	1163	0	0
T5	1229	1205	0	0
T6	1446	1377	0	0
T28	1362	1194	0	0
T29	1501	1478	0	0
T30	1454	1359	0	0
T31	1340	1128	0	0
T32	2243	2060	0	0
T33	1756	1725	0	0
T34	2129	1989	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	T2,T9,T10
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	T2,T9,T10

---

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

	Total	Attempted	Percent	Succeeded/Matched	Percent
Assertions	4	4	100.00	4	100.00
Cover properties	0	0		0
Cover sequences	0	0		0
Total	4	4	100.00	4	100.00

---

Assertion Details

Name	Attempts	Real Successes	Failures	Incomplete
BusySrcReqChk_A	172024014	94348	0	0
DstReqKnown_A	508301125	503726029	0	0
SrcAckBusyChk_A	172024014	25420	0	0
SrcBusyKnown_A	172024014	169411435	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	94348	0	0
T1	11360	32	0	0
T2	36827	63	0	0
T3	0	51	0	0
T9	0	21	0	0
T10	0	168	0	0
T11	0	104	0	0
T27	0	114	0	0
T39	0	9	0	0
T40	0	16	0	0
T50	0	125	0	0
T51	1708	0	0	0
T52	2146	0	0	0
T53	1103	0	0	0
T54	1294	0	0	0
T55	15841	0	0	0
T56	1421	0	0	0
T57	1110	0	0	0
T58	1594	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	508301125	503726029	0	0
T4	1713	1573	0	0
T5	8203	8034	0	0
T6	1459	1390	0	0
T28	1285	1116	0	0
T29	6259	6161	0	0
T30	3029	2831	0	0
T31	1340	1128	0	0
T32	2243	2060	0	0
T33	7028	6902	0	0
T34	2129	1989	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	25420	0	0
T1	11360	12	0	0
T2	36827	26	0	0
T3	0	20	0	0
T9	0	8	0	0
T10	0	42	0	0
T11	0	22	0	0
T27	0	32	0	0
T39	0	4	0	0
T40	0	6	0	0
T50	0	34	0	0
T51	1708	0	0	0
T52	2146	0	0	0
T53	1103	0	0	0
T54	1294	0	0	0
T55	15841	0	0	0
T56	1421	0	0	0
T57	1110	0	0	0
T58	1594	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	169411435	0	0
T4	1267	1163	0	0
T5	1229	1205	0	0
T6	1446	1377	0	0
T28	1362	1194	0	0
T29	1501	1478	0	0
T30	1454	1359	0	0
T31	1340	1128	0	0
T32	2243	2060	0	0
T33	1756	1725	0	0
T34	2129	1989	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	T2,T9,T10
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	T2,T9,T10

---

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

	Total	Attempted	Percent	Succeeded/Matched	Percent
Assertions	4	4	100.00	4	100.00
Cover properties	0	0		0
Cover sequences	0	0		0
Total	4	4	100.00	4	100.00

---

Assertion Details

Name	Attempts	Real Successes	Failures	Incomplete
BusySrcReqChk_A	172024014	136978	0	0
DstReqKnown_A	243862602	241661402	0	0
SrcAckBusyChk_A	172024014	24987	0	0
SrcBusyKnown_A	172024014	169411435	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	136978	0	0
T1	11360	36	0	0
T2	36827	89	0	0
T3	0	51	0	0
T9	0	24	0	0
T10	0	269	0	0
T11	0	99	0	0
T27	0	125	0	0
T39	0	13	0	0
T40	0	25	0	0
T50	0	186	0	0
T51	1708	0	0	0
T52	2146	0	0	0
T53	1103	0	0	0
T54	1294	0	0	0
T55	15841	0	0	0
T56	1421	0	0	0
T57	1110	0	0	0
T58	1594	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	243862602	241661402	0	0
T4	822	755	0	0
T5	3937	3856	0	0
T6	701	668	0	0
T28	628	548	0	0
T29	3004	2957	0	0
T30	1454	1359	0	0
T31	643	541	0	0
T32	1077	989	0	0
T33	3373	3313	0	0
T34	1022	955	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	24987	0	0
T1	11360	8	0	0
T2	36827	26	0	0
T3	0	20	0	0
T9	0	8	0	0
T10	0	42	0	0
T11	0	11	0	0
T27	0	22	0	0
T39	0	4	0	0
T40	0	6	0	0
T50	0	34	0	0
T51	1708	0	0	0
T52	2146	0	0	0
T53	1103	0	0	0
T54	1294	0	0	0
T55	15841	0	0	0
T56	1421	0	0	0
T57	1110	0	0	0
T58	1594	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	169411435	0	0
T4	1267	1163	0	0
T5	1229	1205	0	0
T6	1446	1377	0	0
T28	1362	1194	0	0
T29	1501	1478	0	0
T30	1454	1359	0	0
T31	1340	1128	0	0
T32	2243	2060	0	0
T33	1756	1725	0	0
T34	2129	1989	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,T11,T27
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

	Total	Attempted	Percent	Succeeded/Matched	Percent
Assertions	4	4	100.00	4	100.00
Cover properties	0	0		0
Cover sequences	0	0		0
Total	4	4	100.00	4	100.00

---

Assertion Details

Name	Attempts	Real Successes	Failures	Incomplete
BusySrcReqChk_A	172024014	117949	0	0
DstReqKnown_A	477364878	473024093	0	0
SrcAckBusyChk_A	172024014	30809	0	0
SrcBusyKnown_A	172024014	169411435	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	117949	0	0
T1	11360	64	0	0
T2	36827	62	0	0
T3	0	51	0	0
T9	0	21	0	0
T10	0	167	0	0
T11	0	225	0	0
T27	0	224	0	0
T39	0	9	0	0
T40	0	18	0	0
T50	0	126	0	0
T51	1708	0	0	0
T52	2146	0	0	0
T53	1103	0	0	0
T54	1294	0	0	0
T55	15841	0	0	0
T56	1421	0	0	0
T57	1110	0	0	0
T58	1594	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	477364878	473024093	0	0
T4	1644	1510	0	0
T5	7874	7712	0	0
T6	1402	1336	0	0
T28	1238	1076	0	0
T29	6008	5915	0	0
T30	2907	2718	0	0
T31	1286	1083	0	0
T32	2154	1978	0	0
T33	6747	6626	0	0
T34	2044	1910	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	30809	0	0
T1	11360	24	0	0
T2	36827	26	0	0
T3	0	20	0	0
T9	0	8	0	0
T10	0	42	0	0
T11	0	44	0	0
T27	0	64	0	0
T39	0	4	0	0
T40	0	6	0	0
T50	0	34	0	0
T51	1708	0	0	0
T52	2146	0	0	0
T53	1103	0	0	0
T54	1294	0	0	0
T55	15841	0	0	0
T56	1421	0	0	0
T57	1110	0	0	0
T58	1594	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	169411435	0	0
T4	1267	1163	0	0
T5	1229	1205	0	0
T6	1446	1377	0	0
T28	1362	1194	0	0
T29	1501	1478	0	0
T30	1454	1359	0	0
T31	1340	1128	0	0
T32	2243	2060	0	0
T33	1756	1725	0	0
T34	2129	1989	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,T11,T27
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

	Total	Attempted	Percent	Succeeded/Matched	Percent
Assertions	4	4	100.00	4	100.00
Cover properties	0	0		0
Cover sequences	0	0		0
Total	4	4	100.00	4	100.00

---

Assertion Details

Name	Attempts	Real Successes	Failures	Incomplete
BusySrcReqChk_A	172024014	170197	0	0
DstReqKnown_A	237879213	236797354	0	0
SrcAckBusyChk_A	172024014	30759	0	0
SrcBusyKnown_A	172024014	169411435	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	170197	0	0
T1	11360	88	0	0
T2	36827	88	0	0
T3	0	51	0	0
T9	0	23	0	0
T10	0	265	0	0
T11	0	366	0	0
T27	0	315	0	0
T39	0	13	0	0
T40	0	22	0	0
T50	0	188	0	0
T51	1708	0	0	0
T52	2146	0	0	0
T53	1103	0	0	0
T54	1294	0	0	0
T55	15841	0	0	0
T56	1421	0	0	0
T57	1110	0	0	0
T58	1594	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	237879213	236797354	0	0
T4	810	755	0	0
T5	6844	6823	0	0
T6	682	668	0	0
T28	593	538	0	0
T29	2971	2957	0	0
T30	1466	1432	0	0
T31	598	557	0	0
T32	1037	989	0	0
T33	3435	3414	0	0
T34	1088	1054	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	30759	0	0
T1	11360	24	0	0
T2	36827	26	0	0
T3	0	20	0	0
T9	0	8	0	0
T10	0	42	0	0
T11	0	44	0	0
T27	0	64	0	0
T39	0	4	0	0
T40	0	6	0	0
T50	0	34	0	0
T51	1708	0	0	0
T52	2146	0	0	0
T53	1103	0	0	0
T54	1294	0	0	0
T55	15841	0	0	0
T56	1421	0	0	0
T57	1110	0	0	0
T58	1594	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	169411435	0	0
T4	1267	1163	0	0
T5	1229	1205	0	0
T6	1446	1377	0	0
T28	1362	1194	0	0
T29	1501	1478	0	0
T30	1454	1359	0	0
T31	1340	1128	0	0
T32	2243	2060	0	0
T33	1756	1725	0	0
T34	2129	1989	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,T11,T27
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

	Total	Attempted	Percent	Succeeded/Matched	Percent
Assertions	4	4	100.00	4	100.00
Cover properties	0	0		0
Cover sequences	0	0		0
Total	4	4	100.00	4	100.00

---

Assertion Details

Name	Attempts	Real Successes	Failures	Incomplete
BusySrcReqChk_A	172024014	276992	0	0
DstReqKnown_A	118938936	118398116	0	0
SrcAckBusyChk_A	172024014	30736	0	0
SrcBusyKnown_A	172024014	169411435	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	276992	0	0
T1	11360	128	0	0
T2	36827	124	0	0
T3	0	57	0	0
T9	0	31	0	0
T10	0	446	0	0
T11	0	639	0	0
T27	0	519	0	0
T39	0	18	0	0
T40	0	33	0	0
T50	0	302	0	0
T51	1708	0	0	0
T52	2146	0	0	0
T53	1103	0	0	0
T54	1294	0	0	0
T55	15841	0	0	0
T56	1421	0	0	0
T57	1110	0	0	0
T58	1594	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	118938936	118398116	0	0
T4	405	378	0	0
T5	3422	3412	0	0
T6	341	334	0	0
T28	296	269	0	0
T29	1486	1479	0	0
T30	733	716	0	0
T31	298	277	0	0
T32	519	495	0	0
T33	1717	1706	0	0
T34	542	525	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	30736	0	0
T1	11360	24	0	0
T2	36827	26	0	0
T3	0	20	0	0
T9	0	8	0	0
T10	0	42	0	0
T11	0	44	0	0
T27	0	64	0	0
T39	0	4	0	0
T40	0	6	0	0
T50	0	34	0	0
T51	1708	0	0	0
T52	2146	0	0	0
T53	1103	0	0	0
T54	1294	0	0	0
T55	15841	0	0	0
T56	1421	0	0	0
T57	1110	0	0	0
T58	1594	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	169411435	0	0
T4	1267	1163	0	0
T5	1229	1205	0	0
T6	1446	1377	0	0
T28	1362	1194	0	0
T29	1501	1478	0	0
T30	1454	1359	0	0
T31	1340	1128	0	0
T32	2243	2060	0	0
T33	1756	1725	0	0
T34	2129	1989	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,T11,T27
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

	Total	Attempted	Percent	Succeeded/Matched	Percent
Assertions	4	4	100.00	4	100.00
Cover properties	0	0		0
Cover sequences	0	0		0
Total	4	4	100.00	4	100.00

---

Assertion Details

Name	Attempts	Real Successes	Failures	Incomplete
BusySrcReqChk_A	172024014	114842	0	0
DstReqKnown_A	508301125	503726029	0	0
SrcAckBusyChk_A	172024014	30705	0	0
SrcBusyKnown_A	172024014	169411435	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	114842	0	0
T1	11360	64	0	0
T2	36827	62	0	0
T3	0	51	0	0
T9	0	21	0	0
T10	0	167	0	0
T11	0	221	0	0
T27	0	219	0	0
T39	0	9	0	0
T40	0	16	0	0
T50	0	124	0	0
T51	1708	0	0	0
T52	2146	0	0	0
T53	1103	0	0	0
T54	1294	0	0	0
T55	15841	0	0	0
T56	1421	0	0	0
T57	1110	0	0	0
T58	1594	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	508301125	503726029	0	0
T4	1713	1573	0	0
T5	8203	8034	0	0
T6	1459	1390	0	0
T28	1285	1116	0	0
T29	6259	6161	0	0
T30	3029	2831	0	0
T31	1340	1128	0	0
T32	2243	2060	0	0
T33	7028	6902	0	0
T34	2129	1989	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	30705	0	0
T1	11360	24	0	0
T2	36827	26	0	0
T3	0	20	0	0
T9	0	8	0	0
T10	0	42	0	0
T11	0	44	0	0
T27	0	64	0	0
T39	0	4	0	0
T40	0	6	0	0
T50	0	34	0	0
T51	1708	0	0	0
T52	2146	0	0	0
T53	1103	0	0	0
T54	1294	0	0	0
T55	15841	0	0	0
T56	1421	0	0	0
T57	1110	0	0	0
T58	1594	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	169411435	0	0
T4	1267	1163	0	0
T5	1229	1205	0	0
T6	1446	1377	0	0
T28	1362	1194	0	0
T29	1501	1478	0	0
T30	1454	1359	0	0
T31	1340	1128	0	0
T32	2243	2060	0	0
T33	1756	1725	0	0
T34	2129	1989	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,T11,T27
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

	Total	Attempted	Percent	Succeeded/Matched	Percent
Assertions	4	4	100.00	4	100.00
Cover properties	0	0		0
Cover sequences	0	0		0
Total	4	4	100.00	4	100.00

---

Assertion Details

Name	Attempts	Real Successes	Failures	Incomplete
BusySrcReqChk_A	172024014	170379	0	0
DstReqKnown_A	243862602	241661402	0	0
SrcAckBusyChk_A	172024014	30671	0	0
SrcBusyKnown_A	172024014	169411435	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	170379	0	0
T1	11360	86	0	0
T2	36827	88	0	0
T3	0	51	0	0
T9	0	24	0	0
T10	0	264	0	0
T11	0	356	0	0
T27	0	314	0	0
T39	0	13	0	0
T40	0	23	0	0
T50	0	185	0	0
T51	1708	0	0	0
T52	2146	0	0	0
T53	1103	0	0	0
T54	1294	0	0	0
T55	15841	0	0	0
T56	1421	0	0	0
T57	1110	0	0	0
T58	1594	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	243862602	241661402	0	0
T4	822	755	0	0
T5	3937	3856	0	0
T6	701	668	0	0
T28	628	548	0	0
T29	3004	2957	0	0
T30	1454	1359	0	0
T31	643	541	0	0
T32	1077	989	0	0
T33	3373	3313	0	0
T34	1022	955	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	30671	0	0
T1	11360	24	0	0
T2	36827	26	0	0
T3	0	20	0	0
T9	0	8	0	0
T10	0	42	0	0
T11	0	38	0	0
T27	0	63	0	0
T39	0	4	0	0
T40	0	6	0	0
T50	0	34	0	0
T51	1708	0	0	0
T52	2146	0	0	0
T53	1103	0	0	0
T54	1294	0	0	0
T55	15841	0	0	0
T56	1421	0	0	0
T57	1110	0	0	0
T58	1594	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	172024014	169411435	0	0
T4	1267	1163	0	0
T5	1229	1205	0	0
T6	1446	1377	0	0
T28	1362	1194	0	0
T29	1501	1478	0	0
T30	1454	1359	0	0
T31	1340	1128	0	0
T32	2243	2060	0	0
T33	1756	1725	0	0
T34	2129	1989	0	0