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_2024_08_28/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
99.91	100.00	99.65			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
99.91	100.00	99.65			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
99.91	100.00	99.65			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
99.91	100.00	99.65			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
99.91	100.00	99.65			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
99.91	100.00	99.65			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
99.91	100.00	99.65			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
99.91	100.00	99.65			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
99.91	100.00	99.65			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
99.91	100.00	99.65			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	T3,T7,T39
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	T10,T11,T12
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	T10,T11,T12

---

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	366557000	717838	0	0
DstReqKnown_A	532844550	504670014	0	0
SrcAckBusyChk_A	366557000	142850	0	0
SrcBusyKnown_A	366557000	340130830	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	366557000	717838	0	0
T1	191670	291	0	0
T2	196430	250	0	0
T3	0	4999	0	0
T7	0	4823	0	0
T10	0	2762	0	0
T11	0	2491	0	0
T24	0	125	0	0
T34	9020	0	0	0
T35	0	784	0	0
T37	22050	0	0	0
T38	0	1742	0	0
T39	0	195	0	0
T42	6340	0	0	0
T43	19200	0	0	0
T44	12690	0	0	0
T45	82850	0	0	0
T46	8250	0	0	0
T47	34480	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	532844550	504670014	0	0
T1	123442	122174	0	0
T4	33074	31646	0	0
T5	26616	25556	0	0
T6	16732	15714	0	0
T29	20698	19388	0	0
T30	13410	12752	0	0
T31	59300	58212	0	0
T32	7468	6882	0	0
T33	12428	11432	0	0
T34	24062	22888	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	366557000	142850	0	0
T1	191670	40	0	0
T2	196430	60	0	0
T3	0	582	0	0
T7	0	560	0	0
T10	0	320	0	0
T11	0	700	0	0
T24	0	40	0	0
T34	9020	0	0	0
T35	0	240	0	0
T37	22050	0	0	0
T38	0	360	0	0
T39	0	29	0	0
T42	6340	0	0	0
T43	19200	0	0	0
T44	12690	0	0	0
T45	82850	0	0	0
T46	8250	0	0	0
T47	34480	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	366557000	340130830	0	0
T1	191670	189460	0	0
T4	13150	12510	0	0
T5	20160	19270	0	0
T6	6400	5960	0	0
T29	11190	10430	0	0
T30	10750	10170	0	0
T31	22570	22100	0	0
T32	11520	10450	0	0
T33	10020	8920	0	0
T34	9020	8520	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	T10,T11,T12
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	T10,T11,T12

---

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	36655700	40146	0	0
DstReqKnown_A	79169317	74398494	0	0
SrcAckBusyChk_A	36655700	11516	0	0
SrcBusyKnown_A	36655700	34013083	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	40146	0	0
T1	19167	20	0	0
T2	19643	18	0	0
T3	0	242	0	0
T7	0	201	0	0
T10	0	170	0	0
T11	0	185	0	0
T24	0	10	0	0
T34	902	0	0	0
T35	0	61	0	0
T37	2205	0	0	0
T38	0	123	0	0
T39	0	8	0	0
T42	634	0	0	0
T43	1920	0	0	0
T44	1269	0	0	0
T45	8285	0	0	0
T46	825	0	0	0
T47	3448	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	79169317	74398494	0	0
T1	18775	18558	0	0
T4	5051	4807	0	0
T5	3950	3774	0	0
T6	2563	2387	0	0
T29	3162	2945	0	0
T30	1995	1874	0	0
T31	9032	8842	0	0
T32	1152	1045	0	0
T33	1604	1428	0	0
T34	3611	3408	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	11516	0	0
T1	19167	4	0	0
T2	19643	6	0	0
T3	0	40	0	0
T7	0	40	0	0
T10	0	32	0	0
T11	0	70	0	0
T24	0	4	0	0
T34	902	0	0	0
T35	0	24	0	0
T37	2205	0	0	0
T38	0	36	0	0
T39	0	2	0	0
T42	634	0	0	0
T43	1920	0	0	0
T44	1269	0	0	0
T45	8285	0	0	0
T46	825	0	0	0
T47	3448	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	34013083	0	0
T1	19167	18946	0	0
T4	1315	1251	0	0
T5	2016	1927	0	0
T6	640	596	0	0
T29	1119	1043	0	0
T30	1075	1017	0	0
T31	2257	2210	0	0
T32	1152	1045	0	0
T33	1002	892	0	0
T34	902	852	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	T10,T11,T12
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	T10,T11,T12

---

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	36655700	56987	0	0
DstReqKnown_A	38590100	37387991	0	0
SrcAckBusyChk_A	36655700	11516	0	0
SrcBusyKnown_A	36655700	34013083	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	56987	0	0
T1	19167	30	0	0
T2	19643	25	0	0
T3	0	341	0	0
T7	0	322	0	0
T10	0	269	0	0
T11	0	253	0	0
T24	0	12	0	0
T34	902	0	0	0
T35	0	80	0	0
T37	2205	0	0	0
T38	0	176	0	0
T39	0	14	0	0
T42	634	0	0	0
T43	1920	0	0	0
T44	1269	0	0	0
T45	8285	0	0	0
T46	825	0	0	0
T47	3448	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	38590100	37387991	0	0
T1	9334	9279	0	0
T4	2465	2403	0	0
T5	2180	2125	0	0
T6	1235	1194	0	0
T29	1541	1472	0	0
T30	951	937	0	0
T31	4462	4421	0	0
T32	537	523	0	0
T33	1426	1391	0	0
T34	1902	1854	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	11516	0	0
T1	19167	4	0	0
T2	19643	6	0	0
T3	0	40	0	0
T7	0	40	0	0
T10	0	32	0	0
T11	0	70	0	0
T24	0	4	0	0
T34	902	0	0	0
T35	0	24	0	0
T37	2205	0	0	0
T38	0	36	0	0
T39	0	2	0	0
T42	634	0	0	0
T43	1920	0	0	0
T44	1269	0	0	0
T45	8285	0	0	0
T46	825	0	0	0
T47	3448	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	34013083	0	0
T1	19167	18946	0	0
T4	1315	1251	0	0
T5	2016	1927	0	0
T6	640	596	0	0
T29	1119	1043	0	0
T30	1075	1017	0	0
T31	2257	2210	0	0
T32	1152	1045	0	0
T33	1002	892	0	0
T34	902	852	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	T10,T11,T12
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	T10,T11,T12

---

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	36655700	89984	0	0
DstReqKnown_A	19294625	18693693	0	0
SrcAckBusyChk_A	36655700	11516	0	0
SrcBusyKnown_A	36655700	34013083	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	89984	0	0
T1	19167	49	0	0
T2	19643	38	0	0
T3	0	584	0	0
T7	0	583	0	0
T10	0	481	0	0
T11	0	369	0	0
T24	0	18	0	0
T34	902	0	0	0
T35	0	112	0	0
T37	2205	0	0	0
T38	0	277	0	0
T39	0	22	0	0
T42	634	0	0	0
T43	1920	0	0	0
T44	1269	0	0	0
T45	8285	0	0	0
T46	825	0	0	0
T47	3448	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	19294625	18693693	0	0
T1	4667	4639	0	0
T4	1233	1202	0	0
T5	1089	1061	0	0
T6	617	596	0	0
T29	771	737	0	0
T30	476	469	0	0
T31	2231	2210	0	0
T32	268	261	0	0
T33	713	696	0	0
T34	951	927	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	11516	0	0
T1	19167	4	0	0
T2	19643	6	0	0
T3	0	40	0	0
T7	0	40	0	0
T10	0	32	0	0
T11	0	70	0	0
T24	0	4	0	0
T34	902	0	0	0
T35	0	24	0	0
T37	2205	0	0	0
T38	0	36	0	0
T39	0	2	0	0
T42	634	0	0	0
T43	1920	0	0	0
T44	1269	0	0	0
T45	8285	0	0	0
T46	825	0	0	0
T47	3448	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	34013083	0	0
T1	19167	18946	0	0
T4	1315	1251	0	0
T5	2016	1927	0	0
T6	640	596	0	0
T29	1119	1043	0	0
T30	1075	1017	0	0
T31	2257	2210	0	0
T32	1152	1045	0	0
T33	1002	892	0	0
T34	902	852	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	T10,T11,T12
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	T10,T11,T12

---

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	36655700	39478	0	0
DstReqKnown_A	87383546	82304443	0	0
SrcAckBusyChk_A	36655700	11516	0	0
SrcBusyKnown_A	36655700	34013083	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	39478	0	0
T1	19167	17	0	0
T2	19643	18	0	0
T3	0	196	0	0
T7	0	236	0	0
T10	0	196	0	0
T11	0	181	0	0
T24	0	10	0	0
T34	902	0	0	0
T35	0	61	0	0
T37	2205	0	0	0
T38	0	120	0	0
T39	0	10	0	0
T42	634	0	0	0
T43	1920	0	0	0
T44	1269	0	0	0
T45	8285	0	0	0
T46	825	0	0	0
T47	3448	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	87383546	82304443	0	0
T1	19558	19332	0	0
T4	5262	5007	0	0
T5	4114	3931	0	0
T6	2670	2487	0	0
T29	3294	3068	0	0
T30	2218	2091	0	0
T31	9409	9212	0	0
T32	1201	1089	0	0
T33	1670	1487	0	0
T34	3762	3551	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	11516	0	0
T1	19167	4	0	0
T2	19643	6	0	0
T3	0	40	0	0
T7	0	40	0	0
T10	0	32	0	0
T11	0	70	0	0
T24	0	4	0	0
T34	902	0	0	0
T35	0	24	0	0
T37	2205	0	0	0
T38	0	36	0	0
T39	0	2	0	0
T42	634	0	0	0
T43	1920	0	0	0
T44	1269	0	0	0
T45	8285	0	0	0
T46	825	0	0	0
T47	3448	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	34013083	0	0
T1	19167	18946	0	0
T4	1315	1251	0	0
T5	2016	1927	0	0
T6	640	596	0	0
T29	1119	1043	0	0
T30	1075	1017	0	0
T31	2257	2210	0	0
T32	1152	1045	0	0
T33	1002	892	0	0
T34	902	852	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	T10,T11,T12
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	T10,T11,T12

---

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	36655700	55067	0	0
DstReqKnown_A	41984687	39550386	0	0
SrcAckBusyChk_A	36655700	11046	0	0
SrcBusyKnown_A	36655700	34013083	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	55067	0	0
T1	19167	30	0	0
T2	19643	25	0	0
T3	0	256	0	0
T7	0	190	0	0
T10	0	269	0	0
T11	0	260	0	0
T24	0	12	0	0
T34	902	0	0	0
T35	0	81	0	0
T37	2205	0	0	0
T38	0	174	0	0
T39	0	7	0	0
T42	634	0	0	0
T43	1920	0	0	0
T44	1269	0	0	0
T45	8285	0	0	0
T46	825	0	0	0
T47	3448	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	41984687	39550386	0	0
T1	9387	9279	0	0
T4	2526	2404	0	0
T5	1975	1887	0	0
T6	1281	1193	0	0
T29	1581	1472	0	0
T30	1065	1005	0	0
T31	4516	4421	0	0
T32	576	523	0	0
T33	801	714	0	0
T34	1805	1704	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	11046	0	0
T1	19167	4	0	0
T2	19643	6	0	0
T3	0	23	0	0
T7	0	20	0	0
T10	0	32	0	0
T11	0	70	0	0
T24	0	4	0	0
T34	902	0	0	0
T35	0	24	0	0
T37	2205	0	0	0
T38	0	36	0	0
T39	0	1	0	0
T42	634	0	0	0
T43	1920	0	0	0
T44	1269	0	0	0
T45	8285	0	0	0
T46	825	0	0	0
T47	3448	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	34013083	0	0
T1	19167	18946	0	0
T4	1315	1251	0	0
T5	2016	1927	0	0
T6	640	596	0	0
T29	1119	1043	0	0
T30	1075	1017	0	0
T31	2257	2210	0	0
T32	1152	1045	0	0
T33	1002	892	0	0
T34	902	852	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	T3,T7,T39
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	36655700	61714	0	0
DstReqKnown_A	79169317	74398494	0	0
SrcAckBusyChk_A	36655700	17231	0	0
SrcBusyKnown_A	36655700	34013083	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	61714	0	0
T1	19167	19	0	0
T2	19643	18	0	0
T3	0	482	0	0
T7	0	404	0	0
T10	0	168	0	0
T11	0	185	0	0
T24	0	10	0	0
T34	902	0	0	0
T35	0	61	0	0
T37	2205	0	0	0
T38	0	123	0	0
T39	0	18	0	0
T42	634	0	0	0
T43	1920	0	0	0
T44	1269	0	0	0
T45	8285	0	0	0
T46	825	0	0	0
T47	3448	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	79169317	74398494	0	0
T1	18775	18558	0	0
T4	5051	4807	0	0
T5	3950	3774	0	0
T6	2563	2387	0	0
T29	3162	2945	0	0
T30	1995	1874	0	0
T31	9032	8842	0	0
T32	1152	1045	0	0
T33	1604	1428	0	0
T34	3611	3408	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	17231	0	0
T1	19167	4	0	0
T2	19643	6	0	0
T3	0	80	0	0
T7	0	80	0	0
T10	0	32	0	0
T11	0	70	0	0
T24	0	4	0	0
T34	902	0	0	0
T35	0	24	0	0
T37	2205	0	0	0
T38	0	36	0	0
T39	0	4	0	0
T42	634	0	0	0
T43	1920	0	0	0
T44	1269	0	0	0
T45	8285	0	0	0
T46	825	0	0	0
T47	3448	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	34013083	0	0
T1	19167	18946	0	0
T4	1315	1251	0	0
T5	2016	1927	0	0
T6	640	596	0	0
T29	1119	1043	0	0
T30	1075	1017	0	0
T31	2257	2210	0	0
T32	1152	1045	0	0
T33	1002	892	0	0
T34	902	852	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	T3,T7,T39
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	36655700	87264	0	0
DstReqKnown_A	38590100	37387991	0	0
SrcAckBusyChk_A	36655700	17156	0	0
SrcBusyKnown_A	36655700	34013083	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	87264	0	0
T1	19167	30	0	0
T2	19643	24	0	0
T3	0	688	0	0
T7	0	663	0	0
T10	0	267	0	0
T11	0	254	0	0
T24	0	14	0	0
T34	902	0	0	0
T35	0	81	0	0
T37	2205	0	0	0
T38	0	172	0	0
T39	0	26	0	0
T42	634	0	0	0
T43	1920	0	0	0
T44	1269	0	0	0
T45	8285	0	0	0
T46	825	0	0	0
T47	3448	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	38590100	37387991	0	0
T1	9334	9279	0	0
T4	2465	2403	0	0
T5	2180	2125	0	0
T6	1235	1194	0	0
T29	1541	1472	0	0
T30	951	937	0	0
T31	4462	4421	0	0
T32	537	523	0	0
T33	1426	1391	0	0
T34	1902	1854	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	17156	0	0
T1	19167	4	0	0
T2	19643	6	0	0
T3	0	80	0	0
T7	0	80	0	0
T10	0	32	0	0
T11	0	70	0	0
T24	0	4	0	0
T34	902	0	0	0
T35	0	24	0	0
T37	2205	0	0	0
T38	0	36	0	0
T39	0	4	0	0
T42	634	0	0	0
T43	1920	0	0	0
T44	1269	0	0	0
T45	8285	0	0	0
T46	825	0	0	0
T47	3448	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	34013083	0	0
T1	19167	18946	0	0
T4	1315	1251	0	0
T5	2016	1927	0	0
T6	640	596	0	0
T29	1119	1043	0	0
T30	1075	1017	0	0
T31	2257	2210	0	0
T32	1152	1045	0	0
T33	1002	892	0	0
T34	902	852	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	T3,T7,T39
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	36655700	141006	0	0
DstReqKnown_A	19294625	18693693	0	0
SrcAckBusyChk_A	36655700	17277	0	0
SrcBusyKnown_A	36655700	34013083	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	141006	0	0
T1	19167	48	0	0
T2	19643	42	0	0
T3	0	1175	0	0
T7	0	1181	0	0
T10	0	473	0	0
T11	0	371	0	0
T24	0	17	0	0
T34	902	0	0	0
T35	0	106	0	0
T37	2205	0	0	0
T38	0	280	0	0
T39	0	44	0	0
T42	634	0	0	0
T43	1920	0	0	0
T44	1269	0	0	0
T45	8285	0	0	0
T46	825	0	0	0
T47	3448	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	19294625	18693693	0	0
T1	4667	4639	0	0
T4	1233	1202	0	0
T5	1089	1061	0	0
T6	617	596	0	0
T29	771	737	0	0
T30	476	469	0	0
T31	2231	2210	0	0
T32	268	261	0	0
T33	713	696	0	0
T34	951	927	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	17277	0	0
T1	19167	4	0	0
T2	19643	6	0	0
T3	0	80	0	0
T7	0	80	0	0
T10	0	32	0	0
T11	0	70	0	0
T24	0	4	0	0
T34	902	0	0	0
T35	0	24	0	0
T37	2205	0	0	0
T38	0	36	0	0
T39	0	4	0	0
T42	634	0	0	0
T43	1920	0	0	0
T44	1269	0	0	0
T45	8285	0	0	0
T46	825	0	0	0
T47	3448	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	34013083	0	0
T1	19167	18946	0	0
T4	1315	1251	0	0
T5	2016	1927	0	0
T6	640	596	0	0
T29	1119	1043	0	0
T30	1075	1017	0	0
T31	2257	2210	0	0
T32	1152	1045	0	0
T33	1002	892	0	0
T34	902	852	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	T3,T7,T39
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	36655700	59709	0	0
DstReqKnown_A	87383546	82304443	0	0
SrcAckBusyChk_A	36655700	17110	0	0
SrcBusyKnown_A	36655700	34013083	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	59709	0	0
T1	19167	18	0	0
T2	19643	18	0	0
T3	0	392	0	0
T7	0	478	0	0
T10	0	196	0	0
T11	0	179	0	0
T24	0	10	0	0
T34	902	0	0	0
T35	0	61	0	0
T37	2205	0	0	0
T38	0	122	0	0
T39	0	20	0	0
T42	634	0	0	0
T43	1920	0	0	0
T44	1269	0	0	0
T45	8285	0	0	0
T46	825	0	0	0
T47	3448	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	87383546	82304443	0	0
T1	19558	19332	0	0
T4	5262	5007	0	0
T5	4114	3931	0	0
T6	2670	2487	0	0
T29	3294	3068	0	0
T30	2218	2091	0	0
T31	9409	9212	0	0
T32	1201	1089	0	0
T33	1670	1487	0	0
T34	3762	3551	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	17110	0	0
T1	19167	4	0	0
T2	19643	6	0	0
T3	0	80	0	0
T7	0	80	0	0
T10	0	32	0	0
T11	0	70	0	0
T24	0	4	0	0
T34	902	0	0	0
T35	0	24	0	0
T37	2205	0	0	0
T38	0	36	0	0
T39	0	4	0	0
T42	634	0	0	0
T43	1920	0	0	0
T44	1269	0	0	0
T45	8285	0	0	0
T46	825	0	0	0
T47	3448	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	34013083	0	0
T1	19167	18946	0	0
T4	1315	1251	0	0
T5	2016	1927	0	0
T6	640	596	0	0
T29	1119	1043	0	0
T30	1075	1017	0	0
T31	2257	2210	0	0
T32	1152	1045	0	0
T33	1002	892	0	0
T34	902	852	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	T3,T7,T39
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	36655700	86483	0	0
DstReqKnown_A	41984687	39550386	0	0
SrcAckBusyChk_A	36655700	16966	0	0
SrcBusyKnown_A	36655700	34013083	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	86483	0	0
T1	19167	30	0	0
T2	19643	24	0	0
T3	0	643	0	0
T7	0	565	0	0
T10	0	273	0	0
T11	0	254	0	0
T24	0	12	0	0
T34	902	0	0	0
T35	0	80	0	0
T37	2205	0	0	0
T38	0	175	0	0
T39	0	26	0	0
T42	634	0	0	0
T43	1920	0	0	0
T44	1269	0	0	0
T45	8285	0	0	0
T46	825	0	0	0
T47	3448	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	41984687	39550386	0	0
T1	9387	9279	0	0
T4	2526	2404	0	0
T5	1975	1887	0	0
T6	1281	1193	0	0
T29	1581	1472	0	0
T30	1065	1005	0	0
T31	4516	4421	0	0
T32	576	523	0	0
T33	801	714	0	0
T34	1805	1704	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	16966	0	0
T1	19167	4	0	0
T2	19643	6	0	0
T3	0	79	0	0
T7	0	60	0	0
T10	0	32	0	0
T11	0	70	0	0
T24	0	4	0	0
T34	902	0	0	0
T35	0	24	0	0
T37	2205	0	0	0
T38	0	36	0	0
T39	0	4	0	0
T42	634	0	0	0
T43	1920	0	0	0
T44	1269	0	0	0
T45	8285	0	0	0
T46	825	0	0	0
T47	3448	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	36655700	34013083	0	0
T1	19167	18946	0	0
T4	1315	1251	0	0
T5	2016	1927	0	0
T6	640	596	0	0
T29	1119	1043	0	0
T30	1075	1017	0	0
T31	2257	2210	0	0
T32	1152	1045	0	0
T33	1002	892	0	0
T34	902	852	0	0