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_09_08/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	T1,T50,T27
1	0	Covered	T1,T2,T3

 LINE       109
 EXPRESSION (src_busy_q & ((!src_ack)))
             -----1----   ------2-----

-1-	-2-	Status	Tests
0	1	Covered	T4,T5,T6
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

 LINE       125
 EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
             -----------1-----------    ------------2------------

-1-	-2-	Status	Tests
0	0	Covered	T4,T5,T6
0	1	Covered	T2,T10,T11
1	0	Covered	T1,T2,T3

 LINE       125
 SUB-EXPRESSION (src_busy_q && src_ack)
                 -----1----    ---2---

-1-	-2-	Status	Tests
0	1	Not Covered
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

 LINE       125
 SUB-EXPRESSION (src_update && ((!busy)))
                 -----1----    ----2----

-1-	-2-	Status	Tests
0	1	Covered	T4,T5,T6
1	0	Not Covered
1	1	Covered	T2,T10,T11

---

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	392148570	774452	0	0
DstReqKnown_A	569637658	541087106	0	0
SrcAckBusyChk_A	392148570	157752	0	0
SrcBusyKnown_A	392148570	363660020	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	392148570	774452	0	0
T1	29200	369	0	0
T2	448950	1144	0	0
T3	0	730	0	0
T10	0	1096	0	0
T11	0	547	0	0
T19	21300	0	0	0
T20	13180	0	0	0
T27	0	1509	0	0
T28	0	1795	0	0
T36	0	1090	0	0
T44	9490	0	0	0
T45	287090	0	0	0
T46	17040	0	0	0
T47	30120	0	0	0
T48	22690	0	0	0
T49	13020	0	0	0
T50	0	1864	0	0
T51	0	665	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	569637658	541087106	0	0
T4	25246	24148	0	0
T5	41164	40076	0	0
T6	10818	10302	0	0
T29	9760	8312	0	0
T30	23962	22902	0	0
T31	55530	55084	0	0
T32	81158	79782	0	0
T33	12800	11420	0	0
T34	67232	66076	0	0
T35	51148	50068	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	392148570	157752	0	0
T1	29200	142	0	0
T2	448950	360	0	0
T3	0	140	0	0
T10	0	380	0	0
T11	0	80	0	0
T19	21300	0	0	0
T20	13180	0	0	0
T27	0	563	0	0
T28	0	380	0	0
T36	0	140	0	0
T44	9490	0	0	0
T45	287090	0	0	0
T46	17040	0	0	0
T47	30120	0	0	0
T48	22690	0	0	0
T49	13020	0	0	0
T50	0	215	0	0
T51	0	206	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	392148570	363660020	0	0
T4	19220	18340	0	0
T5	15980	15490	0	0
T6	17270	16300	0	0
T29	15390	12900	0	0
T30	10040	9620	0	0
T31	14950	14810	0	0
T32	18730	18370	0	0
T33	20220	17810	0	0
T34	10950	10700	0	0
T35	17170	16770	0	0

Line Coverage for Instance : tb.dut.u_reg.u_io_meas_ctrl_en_cdc

	Line No.	Total	Covered	Percent
TOTAL		22	22	100.00
CONT_ASSIGN	65	1	1	100.00
ALWAYS	71	6	6	100.00
CONT_ASSIGN	85	1	1	100.00
CONT_ASSIGN	109	1	1	100.00
ALWAYS	115	9	9	100.00
CONT_ASSIGN	150	1	1	100.00
CONT_ASSIGN	155	1	1	100.00
CONT_ASSIGN	156	1	1	100.00
CONT_ASSIGN	200	1	1	100.00

64                      
65         1/1            assign src_req = src_we_i | src_re_i;
           Tests:       T1 T2 T3 
66                      
67                        // busy indication back-pressures upstream if the register is accessed
68                        // again.  The busy indication is also used as a "commit" indication for
69                        // resolving software and hardware write conflicts
70                        always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71         1/1              if (!rst_src_ni) begin
           Tests:       T4 T5 T6 
72         1/1                src_busy_q <= '0;
           Tests:       T4 T5 T6 
73         1/1              end else if (src_req) begin
           Tests:       T4 T5 T6 
74         1/1                src_busy_q <= 1'b1;
           Tests:       T1 T2 T3 
75         1/1              end else if (src_ack) begin
           Tests:       T4 T5 T6 
76         1/1                src_busy_q <= 1'b0;
           Tests:       T1 T2 T3 
77                          end
                        MISSING_ELSE
78                        end
79                      
80                        // A src_ack should only be sent if there was a src_req.
81                        // src_busy_q asserts whenever there is a src_req.  By association,
82                        // whenever src_ack is seen, then src_busy must be high.
83                        `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84                      
85         1/1            assign src_busy_o = src_busy_q;
           Tests:       T1 T2 T3 
86                      
87                        // src_q acts as both the write holding register and the software read back
88                        // register.
89                        // When software performs a write, the write data is captured in src_q for
90                        // CDC purposes.  When not performing a write, the src_q reflects the most recent
91                        // hardware value. For registers with no hardware access, this is simply the
92                        // the value programmed by software (or in the case R1C, W1C etc) the value after
93                        // the operation. For registers with hardware access, this reflects a potentially
94                        // delayed version of the real value, as the software facing updates lag real
95                        // time updates.
96                        //
97                        // To resolve software and hardware conflicts, the process is as follows:
98                        // When software issues a write, this module asserts "busy".  While busy,
99                        // src_q does not take on destination value updates.  Since the
100                       // logic has committed to updating based on software command, there is an irreversible
101                       // window from which hardware writes are ignored.  Once the busy window completes,
102                       // the cdc portion then begins sampling once more.
103                       //
104                       // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105                       // software is always prioritized.  The main difference is the conflict resolution window
106                       // is now larger instead of just one destination clock cycle.
107                     
108                       logic busy;
109        1/1            assign busy = src_busy_q & !src_ack;
           Tests:       T1 T2 T3 
110                     
111                       // This is the current destination value
112                       logic [DataWidth-1:0] dst_qs;
113                       logic src_update;
114                       always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115        1/1              if (!rst_src_ni) begin
           Tests:       T4 T5 T6 
116        1/1                src_q <= ResetVal;
           Tests:       T4 T5 T6 
117        1/1                txn_bits_q <= '0;
           Tests:       T4 T5 T6 
118        1/1              end else if (src_req) begin
           Tests:       T4 T5 T6 
119                           // See assertion below
120                           // At the beginning of a software initiated transaction, the following
121                           // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122                           // change for the duration of the synchronization operation.
123        1/1                src_q <= src_wd_i & BitMask;
           Tests:       T1 T2 T3 
124        1/1                txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
           Tests:       T1 T2 T3 
125        1/1              end else if (src_busy_q && src_ack || src_update && !busy) begin
           Tests:       T4 T5 T6 
126                           // sample data whenever a busy transaction finishes OR
127                           // when an update pulse is seen.
128                           // TODO: We should add a cover group to test different sync timings
129                           // between src_ack and src_update. ie. there can be 3 scenarios:
130                           // 1. update one cycle before ack
131                           // 2. ack one cycle before update
132                           // 3. update / ack on the same cycle
133                           // During all 3 cases the read data should be correct
134        1/1                src_q <= dst_qs;
           Tests:       T1 T2 T3 
135        1/1                txn_bits_q <= '0;
           Tests:       T1 T2 T3 
136                         end
                        MISSING_ELSE
137                       end
138                     
139                       // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140                       // (decoded from address) is busy. So this creates a situation in the current design where
141                       // src_req_i and busy can never be high at the same time.
142                       // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143                       // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144                       // condition cannot be met.
145                       // Thus we add an assertion here to ensure the condition is always satisfied.
146                       `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147                     
148                       // reserved bits are not used
149                       logic unused_wd;
150        1/1            assign unused_wd = ^src_wd_i;
           Tests:       T4 T5 T6 
151                     
152                       // src_q is always updated in the clk_src domain.
153                       // when performing an update to the destination domain, it is guaranteed
154                       // to not change by protocol.
155        1/1            assign src_qs_o = src_q;
           Tests:       T1 T2 T3 
156        1/1            assign dst_wd_o = src_q;
           Tests:       T1 T2 T3 
157                     
158                       ////////////////////////////
159                       // CDC handling
160                       ////////////////////////////
161                     
162                       logic dst_req_from_src;
163                       logic dst_req;
164                     
165                     
166                       // the software transaction is pulse synced across the domain.
167                       // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168                       prim_pulse_sync u_src_to_dst_req (
169                         .clk_src_i,
170                         .rst_src_ni,
171                         .clk_dst_i,
172                         .rst_dst_ni,
173                         .src_pulse_i(src_req),
174                         .dst_pulse_o(dst_req_from_src)
175                       );
176                     
177                       prim_reg_cdc_arb #(
178                         .DataWidth(DataWidth),
179                         .ResetVal(ResetVal),
180                         .DstWrReq(DstWrReq)
181                       ) u_arb (
182                         .clk_src_i,
183                         .rst_src_ni,
184                         .clk_dst_i,
185                         .rst_dst_ni,
186                         .src_ack_o(src_ack),
187                         .src_update_o(src_update),
188                         .dst_req_i(dst_req_from_src),
189                         .dst_req_o(dst_req),
190                         .dst_update_i,
191                         .dst_ds_i,
192                         .dst_qs_i,
193                         .dst_qs_o(dst_qs)
194                       );
195                     
196                     
197                       // Each is valid only when destination request pulse is high; this is important in not propagating
198                       // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199                       // reset.
200        1/1            assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
           Tests:       T1 T2 T3 

---

Cond Coverage for Instance : tb.dut.u_reg.u_io_meas_ctrl_en_cdc

	Total	Covered	Percent
Conditions	14	12	85.71
Logical	14	12	85.71
Non-Logical	0	0
Event	0	0

 LINE       65
 EXPRESSION (src_we_i | src_re_i)
             ----1---   ----2---

-1-	-2-	Status	Tests
0	0	Covered	T4,T5,T6
0	1	Unreachable
1	0	Covered	T1,T2,T3

 LINE       109
 EXPRESSION (src_busy_q & ((!src_ack)))
             -----1----   ------2-----

-1-	-2-	Status	Tests
0	1	Covered	T4,T5,T6
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

 LINE       125
 EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
             -----------1-----------    ------------2------------

-1-	-2-	Status	Tests
0	0	Covered	T4,T5,T6
0	1	Covered	T2,T10,T11
1	0	Covered	T1,T2,T3

 LINE       125
 SUB-EXPRESSION (src_busy_q && src_ack)
                 -----1----    ---2---

-1-	-2-	Status	Tests
0	1	Not Covered
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

 LINE       125
 SUB-EXPRESSION (src_update && ((!busy)))
                 -----1----    ----2----

-1-	-2-	Status	Tests
0	1	Covered	T4,T5,T6
1	0	Not Covered
1	1	Covered	T2,T10,T11

---

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	39214857	43399	0	0
DstReqKnown_A	84591034	79784677	0	0
SrcAckBusyChk_A	39214857	12592	0	0
SrcBusyKnown_A	39214857	36366002	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	43399	0	0
T1	2920	24	0	0
T2	44895	87	0	0
T3	0	49	0	0
T10	0	94	0	0
T11	0	35	0	0
T19	2130	0	0	0
T20	1318	0	0	0
T27	0	95	0	0
T28	0	129	0	0
T36	0	78	0	0
T44	949	0	0	0
T45	28709	0	0	0
T46	1704	0	0	0
T47	3012	0	0	0
T48	2269	0	0	0
T49	1302	0	0	0
T50	0	95	0	0
T51	0	34	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	84591034	79784677	0	0
T4	3843	3668	0	0
T5	6138	5948	0	0
T6	1659	1565	0	0
T29	1507	1263	0	0
T30	3707	3531	0	0
T31	8447	8367	0	0
T32	11992	11762	0	0
T33	1941	1710	0	0
T34	8759	8556	0	0
T35	7495	7319	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	12592	0	0
T1	2920	10	0	0
T2	44895	36	0	0
T3	0	14	0	0
T10	0	38	0	0
T11	0	8	0	0
T19	2130	0	0	0
T20	1318	0	0	0
T27	0	38	0	0
T28	0	38	0	0
T36	0	14	0	0
T44	949	0	0	0
T45	28709	0	0	0
T46	1704	0	0	0
T47	3012	0	0	0
T48	2269	0	0	0
T49	1302	0	0	0
T50	0	18	0	0
T51	0	14	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	36366002	0	0
T4	1922	1834	0	0
T5	1598	1549	0	0
T6	1727	1630	0	0
T29	1539	1290	0	0
T30	1004	962	0	0
T31	1495	1481	0	0
T32	1873	1837	0	0
T33	2022	1781	0	0
T34	1095	1070	0	0
T35	1717	1677	0	0

Line Coverage for Instance : tb.dut.u_reg.u_io_div2_meas_ctrl_en_cdc

	Line No.	Total	Covered	Percent
TOTAL		22	22	100.00
CONT_ASSIGN	65	1	1	100.00
ALWAYS	71	6	6	100.00
CONT_ASSIGN	85	1	1	100.00
CONT_ASSIGN	109	1	1	100.00
ALWAYS	115	9	9	100.00
CONT_ASSIGN	150	1	1	100.00
CONT_ASSIGN	155	1	1	100.00
CONT_ASSIGN	156	1	1	100.00
CONT_ASSIGN	200	1	1	100.00

64                      
65         1/1            assign src_req = src_we_i | src_re_i;
           Tests:       T1 T2 T3 
66                      
67                        // busy indication back-pressures upstream if the register is accessed
68                        // again.  The busy indication is also used as a "commit" indication for
69                        // resolving software and hardware write conflicts
70                        always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71         1/1              if (!rst_src_ni) begin
           Tests:       T4 T5 T6 
72         1/1                src_busy_q <= '0;
           Tests:       T4 T5 T6 
73         1/1              end else if (src_req) begin
           Tests:       T4 T5 T6 
74         1/1                src_busy_q <= 1'b1;
           Tests:       T1 T2 T3 
75         1/1              end else if (src_ack) begin
           Tests:       T4 T5 T6 
76         1/1                src_busy_q <= 1'b0;
           Tests:       T1 T2 T3 
77                          end
                        MISSING_ELSE
78                        end
79                      
80                        // A src_ack should only be sent if there was a src_req.
81                        // src_busy_q asserts whenever there is a src_req.  By association,
82                        // whenever src_ack is seen, then src_busy must be high.
83                        `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84                      
85         1/1            assign src_busy_o = src_busy_q;
           Tests:       T1 T2 T3 
86                      
87                        // src_q acts as both the write holding register and the software read back
88                        // register.
89                        // When software performs a write, the write data is captured in src_q for
90                        // CDC purposes.  When not performing a write, the src_q reflects the most recent
91                        // hardware value. For registers with no hardware access, this is simply the
92                        // the value programmed by software (or in the case R1C, W1C etc) the value after
93                        // the operation. For registers with hardware access, this reflects a potentially
94                        // delayed version of the real value, as the software facing updates lag real
95                        // time updates.
96                        //
97                        // To resolve software and hardware conflicts, the process is as follows:
98                        // When software issues a write, this module asserts "busy".  While busy,
99                        // src_q does not take on destination value updates.  Since the
100                       // logic has committed to updating based on software command, there is an irreversible
101                       // window from which hardware writes are ignored.  Once the busy window completes,
102                       // the cdc portion then begins sampling once more.
103                       //
104                       // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105                       // software is always prioritized.  The main difference is the conflict resolution window
106                       // is now larger instead of just one destination clock cycle.
107                     
108                       logic busy;
109        1/1            assign busy = src_busy_q & !src_ack;
           Tests:       T1 T2 T3 
110                     
111                       // This is the current destination value
112                       logic [DataWidth-1:0] dst_qs;
113                       logic src_update;
114                       always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115        1/1              if (!rst_src_ni) begin
           Tests:       T4 T5 T6 
116        1/1                src_q <= ResetVal;
           Tests:       T4 T5 T6 
117        1/1                txn_bits_q <= '0;
           Tests:       T4 T5 T6 
118        1/1              end else if (src_req) begin
           Tests:       T4 T5 T6 
119                           // See assertion below
120                           // At the beginning of a software initiated transaction, the following
121                           // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122                           // change for the duration of the synchronization operation.
123        1/1                src_q <= src_wd_i & BitMask;
           Tests:       T1 T2 T3 
124        1/1                txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
           Tests:       T1 T2 T3 
125        1/1              end else if (src_busy_q && src_ack || src_update && !busy) begin
           Tests:       T4 T5 T6 
126                           // sample data whenever a busy transaction finishes OR
127                           // when an update pulse is seen.
128                           // TODO: We should add a cover group to test different sync timings
129                           // between src_ack and src_update. ie. there can be 3 scenarios:
130                           // 1. update one cycle before ack
131                           // 2. ack one cycle before update
132                           // 3. update / ack on the same cycle
133                           // During all 3 cases the read data should be correct
134        1/1                src_q <= dst_qs;
           Tests:       T1 T2 T3 
135        1/1                txn_bits_q <= '0;
           Tests:       T1 T2 T3 
136                         end
                        MISSING_ELSE
137                       end
138                     
139                       // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140                       // (decoded from address) is busy. So this creates a situation in the current design where
141                       // src_req_i and busy can never be high at the same time.
142                       // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143                       // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144                       // condition cannot be met.
145                       // Thus we add an assertion here to ensure the condition is always satisfied.
146                       `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147                     
148                       // reserved bits are not used
149                       logic unused_wd;
150        1/1            assign unused_wd = ^src_wd_i;
           Tests:       T4 T5 T6 
151                     
152                       // src_q is always updated in the clk_src domain.
153                       // when performing an update to the destination domain, it is guaranteed
154                       // to not change by protocol.
155        1/1            assign src_qs_o = src_q;
           Tests:       T1 T2 T3 
156        1/1            assign dst_wd_o = src_q;
           Tests:       T1 T2 T3 
157                     
158                       ////////////////////////////
159                       // CDC handling
160                       ////////////////////////////
161                     
162                       logic dst_req_from_src;
163                       logic dst_req;
164                     
165                     
166                       // the software transaction is pulse synced across the domain.
167                       // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168                       prim_pulse_sync u_src_to_dst_req (
169                         .clk_src_i,
170                         .rst_src_ni,
171                         .clk_dst_i,
172                         .rst_dst_ni,
173                         .src_pulse_i(src_req),
174                         .dst_pulse_o(dst_req_from_src)
175                       );
176                     
177                       prim_reg_cdc_arb #(
178                         .DataWidth(DataWidth),
179                         .ResetVal(ResetVal),
180                         .DstWrReq(DstWrReq)
181                       ) u_arb (
182                         .clk_src_i,
183                         .rst_src_ni,
184                         .clk_dst_i,
185                         .rst_dst_ni,
186                         .src_ack_o(src_ack),
187                         .src_update_o(src_update),
188                         .dst_req_i(dst_req_from_src),
189                         .dst_req_o(dst_req),
190                         .dst_update_i,
191                         .dst_ds_i,
192                         .dst_qs_i,
193                         .dst_qs_o(dst_qs)
194                       );
195                     
196                     
197                       // Each is valid only when destination request pulse is high; this is important in not propagating
198                       // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199                       // reset.
200        1/1            assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
           Tests:       T1 T2 T3 

---

Cond Coverage for Instance : tb.dut.u_reg.u_io_div2_meas_ctrl_en_cdc

	Total	Covered	Percent
Conditions	14	12	85.71
Logical	14	12	85.71
Non-Logical	0	0
Event	0	0

 LINE       65
 EXPRESSION (src_we_i | src_re_i)
             ----1---   ----2---

-1-	-2-	Status	Tests
0	0	Covered	T4,T5,T6
0	1	Unreachable
1	0	Covered	T1,T2,T3

 LINE       109
 EXPRESSION (src_busy_q & ((!src_ack)))
             -----1----   ------2-----

-1-	-2-	Status	Tests
0	1	Covered	T4,T5,T6
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

 LINE       125
 EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
             -----------1-----------    ------------2------------

-1-	-2-	Status	Tests
0	0	Covered	T4,T5,T6
0	1	Covered	T2,T10,T11
1	0	Covered	T1,T2,T3

 LINE       125
 SUB-EXPRESSION (src_busy_q && src_ack)
                 -----1----    ---2---

-1-	-2-	Status	Tests
0	1	Not Covered
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

 LINE       125
 SUB-EXPRESSION (src_update && ((!busy)))
                 -----1----    ----2----

-1-	-2-	Status	Tests
0	1	Covered	T4,T5,T6
1	0	Not Covered
1	1	Covered	T2,T10,T11

---

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	39214857	61567	0	0
DstReqKnown_A	41278982	40071537	0	0
SrcAckBusyChk_A	39214857	12592	0	0
SrcBusyKnown_A	39214857	36366002	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	61567	0	0
T1	2920	24	0	0
T2	44895	120	0	0
T3	0	70	0	0
T10	0	108	0	0
T11	0	56	0	0
T19	2130	0	0	0
T20	1318	0	0	0
T27	0	95	0	0
T28	0	180	0	0
T36	0	115	0	0
T44	949	0	0	0
T45	28709	0	0	0
T46	1704	0	0	0
T47	3012	0	0	0
T48	2269	0	0	0
T49	1302	0	0	0
T50	0	149	0	0
T51	0	46	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	41278982	40071537	0	0
T4	1903	1834	0	0
T5	3321	3280	0	0
T6	796	782	0	0
T29	700	631	0	0
T30	1821	1766	0	0
T31	4197	4183	0	0
T32	6732	6663	0	0
T33	978	909	0	0
T34	7568	7527	0	0
T35	4351	4289	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	12592	0	0
T1	2920	10	0	0
T2	44895	36	0	0
T3	0	14	0	0
T10	0	38	0	0
T11	0	8	0	0
T19	2130	0	0	0
T20	1318	0	0	0
T27	0	38	0	0
T28	0	38	0	0
T36	0	14	0	0
T44	949	0	0	0
T45	28709	0	0	0
T46	1704	0	0	0
T47	3012	0	0	0
T48	2269	0	0	0
T49	1302	0	0	0
T50	0	18	0	0
T51	0	14	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	36366002	0	0
T4	1922	1834	0	0
T5	1598	1549	0	0
T6	1727	1630	0	0
T29	1539	1290	0	0
T30	1004	962	0	0
T31	1495	1481	0	0
T32	1873	1837	0	0
T33	2022	1781	0	0
T34	1095	1070	0	0
T35	1717	1677	0	0

Line Coverage for Instance : tb.dut.u_reg.u_io_div4_meas_ctrl_en_cdc

	Line No.	Total	Covered	Percent
TOTAL		22	22	100.00
CONT_ASSIGN	65	1	1	100.00
ALWAYS	71	6	6	100.00
CONT_ASSIGN	85	1	1	100.00
CONT_ASSIGN	109	1	1	100.00
ALWAYS	115	9	9	100.00
CONT_ASSIGN	150	1	1	100.00
CONT_ASSIGN	155	1	1	100.00
CONT_ASSIGN	156	1	1	100.00
CONT_ASSIGN	200	1	1	100.00

64                      
65         1/1            assign src_req = src_we_i | src_re_i;
           Tests:       T1 T2 T3 
66                      
67                        // busy indication back-pressures upstream if the register is accessed
68                        // again.  The busy indication is also used as a "commit" indication for
69                        // resolving software and hardware write conflicts
70                        always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71         1/1              if (!rst_src_ni) begin
           Tests:       T4 T5 T6 
72         1/1                src_busy_q <= '0;
           Tests:       T4 T5 T6 
73         1/1              end else if (src_req) begin
           Tests:       T4 T5 T6 
74         1/1                src_busy_q <= 1'b1;
           Tests:       T1 T2 T3 
75         1/1              end else if (src_ack) begin
           Tests:       T4 T5 T6 
76         1/1                src_busy_q <= 1'b0;
           Tests:       T1 T2 T3 
77                          end
                        MISSING_ELSE
78                        end
79                      
80                        // A src_ack should only be sent if there was a src_req.
81                        // src_busy_q asserts whenever there is a src_req.  By association,
82                        // whenever src_ack is seen, then src_busy must be high.
83                        `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84                      
85         1/1            assign src_busy_o = src_busy_q;
           Tests:       T1 T2 T3 
86                      
87                        // src_q acts as both the write holding register and the software read back
88                        // register.
89                        // When software performs a write, the write data is captured in src_q for
90                        // CDC purposes.  When not performing a write, the src_q reflects the most recent
91                        // hardware value. For registers with no hardware access, this is simply the
92                        // the value programmed by software (or in the case R1C, W1C etc) the value after
93                        // the operation. For registers with hardware access, this reflects a potentially
94                        // delayed version of the real value, as the software facing updates lag real
95                        // time updates.
96                        //
97                        // To resolve software and hardware conflicts, the process is as follows:
98                        // When software issues a write, this module asserts "busy".  While busy,
99                        // src_q does not take on destination value updates.  Since the
100                       // logic has committed to updating based on software command, there is an irreversible
101                       // window from which hardware writes are ignored.  Once the busy window completes,
102                       // the cdc portion then begins sampling once more.
103                       //
104                       // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105                       // software is always prioritized.  The main difference is the conflict resolution window
106                       // is now larger instead of just one destination clock cycle.
107                     
108                       logic busy;
109        1/1            assign busy = src_busy_q & !src_ack;
           Tests:       T1 T2 T3 
110                     
111                       // This is the current destination value
112                       logic [DataWidth-1:0] dst_qs;
113                       logic src_update;
114                       always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115        1/1              if (!rst_src_ni) begin
           Tests:       T4 T5 T6 
116        1/1                src_q <= ResetVal;
           Tests:       T4 T5 T6 
117        1/1                txn_bits_q <= '0;
           Tests:       T4 T5 T6 
118        1/1              end else if (src_req) begin
           Tests:       T4 T5 T6 
119                           // See assertion below
120                           // At the beginning of a software initiated transaction, the following
121                           // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122                           // change for the duration of the synchronization operation.
123        1/1                src_q <= src_wd_i & BitMask;
           Tests:       T1 T2 T3 
124        1/1                txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
           Tests:       T1 T2 T3 
125        1/1              end else if (src_busy_q && src_ack || src_update && !busy) begin
           Tests:       T4 T5 T6 
126                           // sample data whenever a busy transaction finishes OR
127                           // when an update pulse is seen.
128                           // TODO: We should add a cover group to test different sync timings
129                           // between src_ack and src_update. ie. there can be 3 scenarios:
130                           // 1. update one cycle before ack
131                           // 2. ack one cycle before update
132                           // 3. update / ack on the same cycle
133                           // During all 3 cases the read data should be correct
134        1/1                src_q <= dst_qs;
           Tests:       T1 T2 T3 
135        1/1                txn_bits_q <= '0;
           Tests:       T1 T2 T3 
136                         end
                        MISSING_ELSE
137                       end
138                     
139                       // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140                       // (decoded from address) is busy. So this creates a situation in the current design where
141                       // src_req_i and busy can never be high at the same time.
142                       // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143                       // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144                       // condition cannot be met.
145                       // Thus we add an assertion here to ensure the condition is always satisfied.
146                       `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147                     
148                       // reserved bits are not used
149                       logic unused_wd;
150        1/1            assign unused_wd = ^src_wd_i;
           Tests:       T4 T5 T6 
151                     
152                       // src_q is always updated in the clk_src domain.
153                       // when performing an update to the destination domain, it is guaranteed
154                       // to not change by protocol.
155        1/1            assign src_qs_o = src_q;
           Tests:       T1 T2 T3 
156        1/1            assign dst_wd_o = src_q;
           Tests:       T1 T2 T3 
157                     
158                       ////////////////////////////
159                       // CDC handling
160                       ////////////////////////////
161                     
162                       logic dst_req_from_src;
163                       logic dst_req;
164                     
165                     
166                       // the software transaction is pulse synced across the domain.
167                       // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168                       prim_pulse_sync u_src_to_dst_req (
169                         .clk_src_i,
170                         .rst_src_ni,
171                         .clk_dst_i,
172                         .rst_dst_ni,
173                         .src_pulse_i(src_req),
174                         .dst_pulse_o(dst_req_from_src)
175                       );
176                     
177                       prim_reg_cdc_arb #(
178                         .DataWidth(DataWidth),
179                         .ResetVal(ResetVal),
180                         .DstWrReq(DstWrReq)
181                       ) u_arb (
182                         .clk_src_i,
183                         .rst_src_ni,
184                         .clk_dst_i,
185                         .rst_dst_ni,
186                         .src_ack_o(src_ack),
187                         .src_update_o(src_update),
188                         .dst_req_i(dst_req_from_src),
189                         .dst_req_o(dst_req),
190                         .dst_update_i,
191                         .dst_ds_i,
192                         .dst_qs_i,
193                         .dst_qs_o(dst_qs)
194                       );
195                     
196                     
197                       // Each is valid only when destination request pulse is high; this is important in not propagating
198                       // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199                       // reset.
200        1/1            assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
           Tests:       T1 T2 T3 

---

Cond Coverage for Instance : tb.dut.u_reg.u_io_div4_meas_ctrl_en_cdc

	Total	Covered	Percent
Conditions	14	12	85.71
Logical	14	12	85.71
Non-Logical	0	0
Event	0	0

 LINE       65
 EXPRESSION (src_we_i | src_re_i)
             ----1---   ----2---

-1-	-2-	Status	Tests
0	0	Covered	T4,T5,T6
0	1	Unreachable
1	0	Covered	T1,T2,T3

 LINE       109
 EXPRESSION (src_busy_q & ((!src_ack)))
             -----1----   ------2-----

-1-	-2-	Status	Tests
0	1	Covered	T4,T5,T6
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

 LINE       125
 EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
             -----------1-----------    ------------2------------

-1-	-2-	Status	Tests
0	0	Covered	T4,T5,T6
0	1	Covered	T2,T10,T11
1	0	Covered	T1,T2,T3

 LINE       125
 SUB-EXPRESSION (src_busy_q && src_ack)
                 -----1----    ---2---

-1-	-2-	Status	Tests
0	1	Not Covered
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

 LINE       125
 SUB-EXPRESSION (src_update && ((!busy)))
                 -----1----    ----2----

-1-	-2-	Status	Tests
0	1	Covered	T4,T5,T6
1	0	Not Covered
1	1	Covered	T2,T10,T11

---

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	39214857	97768	0	0
DstReqKnown_A	20639099	20035472	0	0
SrcAckBusyChk_A	39214857	12592	0	0
SrcBusyKnown_A	39214857	36366002	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	97768	0	0
T1	2920	24	0	0
T2	44895	159	0	0
T3	0	111	0	0
T10	0	144	0	0
T11	0	90	0	0
T19	2130	0	0	0
T20	1318	0	0	0
T27	0	131	0	0
T28	0	287	0	0
T36	0	188	0	0
T44	949	0	0	0
T45	28709	0	0	0
T46	1704	0	0	0
T47	3012	0	0	0
T48	2269	0	0	0
T49	1302	0	0	0
T50	0	271	0	0
T51	0	63	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	20639099	20035472	0	0
T4	951	917	0	0
T5	1661	1640	0	0
T6	398	391	0	0
T29	350	316	0	0
T30	910	882	0	0
T31	2099	2092	0	0
T32	3365	3331	0	0
T33	489	455	0	0
T34	3784	3763	0	0
T35	2173	2142	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	12592	0	0
T1	2920	10	0	0
T2	44895	36	0	0
T3	0	14	0	0
T10	0	38	0	0
T11	0	8	0	0
T19	2130	0	0	0
T20	1318	0	0	0
T27	0	38	0	0
T28	0	38	0	0
T36	0	14	0	0
T44	949	0	0	0
T45	28709	0	0	0
T46	1704	0	0	0
T47	3012	0	0	0
T48	2269	0	0	0
T49	1302	0	0	0
T50	0	18	0	0
T51	0	14	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	36366002	0	0
T4	1922	1834	0	0
T5	1598	1549	0	0
T6	1727	1630	0	0
T29	1539	1290	0	0
T30	1004	962	0	0
T31	1495	1481	0	0
T32	1873	1837	0	0
T33	2022	1781	0	0
T34	1095	1070	0	0
T35	1717	1677	0	0

Line Coverage for Instance : tb.dut.u_reg.u_main_meas_ctrl_en_cdc

	Line No.	Total	Covered	Percent
TOTAL		22	22	100.00
CONT_ASSIGN	65	1	1	100.00
ALWAYS	71	6	6	100.00
CONT_ASSIGN	85	1	1	100.00
CONT_ASSIGN	109	1	1	100.00
ALWAYS	115	9	9	100.00
CONT_ASSIGN	150	1	1	100.00
CONT_ASSIGN	155	1	1	100.00
CONT_ASSIGN	156	1	1	100.00
CONT_ASSIGN	200	1	1	100.00

64                      
65         1/1            assign src_req = src_we_i | src_re_i;
           Tests:       T1 T2 T3 
66                      
67                        // busy indication back-pressures upstream if the register is accessed
68                        // again.  The busy indication is also used as a "commit" indication for
69                        // resolving software and hardware write conflicts
70                        always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71         1/1              if (!rst_src_ni) begin
           Tests:       T4 T5 T6 
72         1/1                src_busy_q <= '0;
           Tests:       T4 T5 T6 
73         1/1              end else if (src_req) begin
           Tests:       T4 T5 T6 
74         1/1                src_busy_q <= 1'b1;
           Tests:       T1 T2 T3 
75         1/1              end else if (src_ack) begin
           Tests:       T4 T5 T6 
76         1/1                src_busy_q <= 1'b0;
           Tests:       T1 T2 T3 
77                          end
                        MISSING_ELSE
78                        end
79                      
80                        // A src_ack should only be sent if there was a src_req.
81                        // src_busy_q asserts whenever there is a src_req.  By association,
82                        // whenever src_ack is seen, then src_busy must be high.
83                        `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84                      
85         1/1            assign src_busy_o = src_busy_q;
           Tests:       T1 T2 T3 
86                      
87                        // src_q acts as both the write holding register and the software read back
88                        // register.
89                        // When software performs a write, the write data is captured in src_q for
90                        // CDC purposes.  When not performing a write, the src_q reflects the most recent
91                        // hardware value. For registers with no hardware access, this is simply the
92                        // the value programmed by software (or in the case R1C, W1C etc) the value after
93                        // the operation. For registers with hardware access, this reflects a potentially
94                        // delayed version of the real value, as the software facing updates lag real
95                        // time updates.
96                        //
97                        // To resolve software and hardware conflicts, the process is as follows:
98                        // When software issues a write, this module asserts "busy".  While busy,
99                        // src_q does not take on destination value updates.  Since the
100                       // logic has committed to updating based on software command, there is an irreversible
101                       // window from which hardware writes are ignored.  Once the busy window completes,
102                       // the cdc portion then begins sampling once more.
103                       //
104                       // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105                       // software is always prioritized.  The main difference is the conflict resolution window
106                       // is now larger instead of just one destination clock cycle.
107                     
108                       logic busy;
109        1/1            assign busy = src_busy_q & !src_ack;
           Tests:       T1 T2 T3 
110                     
111                       // This is the current destination value
112                       logic [DataWidth-1:0] dst_qs;
113                       logic src_update;
114                       always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115        1/1              if (!rst_src_ni) begin
           Tests:       T4 T5 T6 
116        1/1                src_q <= ResetVal;
           Tests:       T4 T5 T6 
117        1/1                txn_bits_q <= '0;
           Tests:       T4 T5 T6 
118        1/1              end else if (src_req) begin
           Tests:       T4 T5 T6 
119                           // See assertion below
120                           // At the beginning of a software initiated transaction, the following
121                           // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122                           // change for the duration of the synchronization operation.
123        1/1                src_q <= src_wd_i & BitMask;
           Tests:       T1 T2 T3 
124        1/1                txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
           Tests:       T1 T2 T3 
125        1/1              end else if (src_busy_q && src_ack || src_update && !busy) begin
           Tests:       T4 T5 T6 
126                           // sample data whenever a busy transaction finishes OR
127                           // when an update pulse is seen.
128                           // TODO: We should add a cover group to test different sync timings
129                           // between src_ack and src_update. ie. there can be 3 scenarios:
130                           // 1. update one cycle before ack
131                           // 2. ack one cycle before update
132                           // 3. update / ack on the same cycle
133                           // During all 3 cases the read data should be correct
134        1/1                src_q <= dst_qs;
           Tests:       T1 T2 T3 
135        1/1                txn_bits_q <= '0;
           Tests:       T1 T2 T3 
136                         end
                        MISSING_ELSE
137                       end
138                     
139                       // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140                       // (decoded from address) is busy. So this creates a situation in the current design where
141                       // src_req_i and busy can never be high at the same time.
142                       // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143                       // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144                       // condition cannot be met.
145                       // Thus we add an assertion here to ensure the condition is always satisfied.
146                       `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147                     
148                       // reserved bits are not used
149                       logic unused_wd;
150        1/1            assign unused_wd = ^src_wd_i;
           Tests:       T4 T5 T6 
151                     
152                       // src_q is always updated in the clk_src domain.
153                       // when performing an update to the destination domain, it is guaranteed
154                       // to not change by protocol.
155        1/1            assign src_qs_o = src_q;
           Tests:       T1 T2 T3 
156        1/1            assign dst_wd_o = src_q;
           Tests:       T1 T2 T3 
157                     
158                       ////////////////////////////
159                       // CDC handling
160                       ////////////////////////////
161                     
162                       logic dst_req_from_src;
163                       logic dst_req;
164                     
165                     
166                       // the software transaction is pulse synced across the domain.
167                       // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168                       prim_pulse_sync u_src_to_dst_req (
169                         .clk_src_i,
170                         .rst_src_ni,
171                         .clk_dst_i,
172                         .rst_dst_ni,
173                         .src_pulse_i(src_req),
174                         .dst_pulse_o(dst_req_from_src)
175                       );
176                     
177                       prim_reg_cdc_arb #(
178                         .DataWidth(DataWidth),
179                         .ResetVal(ResetVal),
180                         .DstWrReq(DstWrReq)
181                       ) u_arb (
182                         .clk_src_i,
183                         .rst_src_ni,
184                         .clk_dst_i,
185                         .rst_dst_ni,
186                         .src_ack_o(src_ack),
187                         .src_update_o(src_update),
188                         .dst_req_i(dst_req_from_src),
189                         .dst_req_o(dst_req),
190                         .dst_update_i,
191                         .dst_ds_i,
192                         .dst_qs_i,
193                         .dst_qs_o(dst_qs)
194                       );
195                     
196                     
197                       // Each is valid only when destination request pulse is high; this is important in not propagating
198                       // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199                       // reset.
200        1/1            assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
           Tests:       T1 T2 T3 

---

Cond Coverage for Instance : tb.dut.u_reg.u_main_meas_ctrl_en_cdc

	Total	Covered	Percent
Conditions	14	12	85.71
Logical	14	12	85.71
Non-Logical	0	0
Event	0	0

 LINE       65
 EXPRESSION (src_we_i | src_re_i)
             ----1---   ----2---

-1-	-2-	Status	Tests
0	0	Covered	T4,T5,T6
0	1	Unreachable
1	0	Covered	T1,T2,T3

 LINE       109
 EXPRESSION (src_busy_q & ((!src_ack)))
             -----1----   ------2-----

-1-	-2-	Status	Tests
0	1	Covered	T4,T5,T6
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

 LINE       125
 EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
             -----------1-----------    ------------2------------

-1-	-2-	Status	Tests
0	0	Covered	T4,T5,T6
0	1	Covered	T2,T10,T11
1	0	Covered	T1,T2,T3

 LINE       125
 SUB-EXPRESSION (src_busy_q && src_ack)
                 -----1----    ---2---

-1-	-2-	Status	Tests
0	1	Not Covered
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

 LINE       125
 SUB-EXPRESSION (src_update && ((!busy)))
                 -----1----    ----2----

-1-	-2-	Status	Tests
0	1	Covered	T4,T5,T6
1	0	Not Covered
1	1	Covered	T2,T10,T11

---

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	39214857	43326	0	0
DstReqKnown_A	93466052	88294483	0	0
SrcAckBusyChk_A	39214857	12592	0	0
SrcBusyKnown_A	39214857	36366002	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	43326	0	0
T1	2920	24	0	0
T2	44895	87	0	0
T3	0	48	0	0
T10	0	94	0	0
T11	0	34	0	0
T19	2130	0	0	0
T20	1318	0	0	0
T27	0	95	0	0
T28	0	120	0	0
T36	0	64	0	0
T44	949	0	0	0
T45	28709	0	0	0
T46	1704	0	0	0
T47	3012	0	0	0
T48	2269	0	0	0
T49	1302	0	0	0
T50	0	110	0	0
T51	0	34	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	93466052	88294483	0	0
T4	4004	3821	0	0
T5	6393	6196	0	0
T6	1727	1630	0	0
T29	1570	1315	0	0
T30	3604	3420	0	0
T31	8799	8716	0	0
T32	12493	12253	0	0
T33	2022	1781	0	0
T34	9125	8913	0	0
T35	7808	7625	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	12592	0	0
T1	2920	10	0	0
T2	44895	36	0	0
T3	0	14	0	0
T10	0	38	0	0
T11	0	8	0	0
T19	2130	0	0	0
T20	1318	0	0	0
T27	0	38	0	0
T28	0	38	0	0
T36	0	14	0	0
T44	949	0	0	0
T45	28709	0	0	0
T46	1704	0	0	0
T47	3012	0	0	0
T48	2269	0	0	0
T49	1302	0	0	0
T50	0	18	0	0
T51	0	14	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	36366002	0	0
T4	1922	1834	0	0
T5	1598	1549	0	0
T6	1727	1630	0	0
T29	1539	1290	0	0
T30	1004	962	0	0
T31	1495	1481	0	0
T32	1873	1837	0	0
T33	2022	1781	0	0
T34	1095	1070	0	0
T35	1717	1677	0	0

Line Coverage for Instance : tb.dut.u_reg.u_usb_meas_ctrl_en_cdc

	Line No.	Total	Covered	Percent
TOTAL		22	22	100.00
CONT_ASSIGN	65	1	1	100.00
ALWAYS	71	6	6	100.00
CONT_ASSIGN	85	1	1	100.00
CONT_ASSIGN	109	1	1	100.00
ALWAYS	115	9	9	100.00
CONT_ASSIGN	150	1	1	100.00
CONT_ASSIGN	155	1	1	100.00
CONT_ASSIGN	156	1	1	100.00
CONT_ASSIGN	200	1	1	100.00

64                      
65         1/1            assign src_req = src_we_i | src_re_i;
           Tests:       T1 T2 T3 
66                      
67                        // busy indication back-pressures upstream if the register is accessed
68                        // again.  The busy indication is also used as a "commit" indication for
69                        // resolving software and hardware write conflicts
70                        always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71         1/1              if (!rst_src_ni) begin
           Tests:       T4 T5 T6 
72         1/1                src_busy_q <= '0;
           Tests:       T4 T5 T6 
73         1/1              end else if (src_req) begin
           Tests:       T4 T5 T6 
74         1/1                src_busy_q <= 1'b1;
           Tests:       T1 T2 T3 
75         1/1              end else if (src_ack) begin
           Tests:       T4 T5 T6 
76         1/1                src_busy_q <= 1'b0;
           Tests:       T1 T2 T3 
77                          end
                        MISSING_ELSE
78                        end
79                      
80                        // A src_ack should only be sent if there was a src_req.
81                        // src_busy_q asserts whenever there is a src_req.  By association,
82                        // whenever src_ack is seen, then src_busy must be high.
83                        `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84                      
85         1/1            assign src_busy_o = src_busy_q;
           Tests:       T1 T2 T3 
86                      
87                        // src_q acts as both the write holding register and the software read back
88                        // register.
89                        // When software performs a write, the write data is captured in src_q for
90                        // CDC purposes.  When not performing a write, the src_q reflects the most recent
91                        // hardware value. For registers with no hardware access, this is simply the
92                        // the value programmed by software (or in the case R1C, W1C etc) the value after
93                        // the operation. For registers with hardware access, this reflects a potentially
94                        // delayed version of the real value, as the software facing updates lag real
95                        // time updates.
96                        //
97                        // To resolve software and hardware conflicts, the process is as follows:
98                        // When software issues a write, this module asserts "busy".  While busy,
99                        // src_q does not take on destination value updates.  Since the
100                       // logic has committed to updating based on software command, there is an irreversible
101                       // window from which hardware writes are ignored.  Once the busy window completes,
102                       // the cdc portion then begins sampling once more.
103                       //
104                       // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105                       // software is always prioritized.  The main difference is the conflict resolution window
106                       // is now larger instead of just one destination clock cycle.
107                     
108                       logic busy;
109        1/1            assign busy = src_busy_q & !src_ack;
           Tests:       T1 T2 T3 
110                     
111                       // This is the current destination value
112                       logic [DataWidth-1:0] dst_qs;
113                       logic src_update;
114                       always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115        1/1              if (!rst_src_ni) begin
           Tests:       T4 T5 T6 
116        1/1                src_q <= ResetVal;
           Tests:       T4 T5 T6 
117        1/1                txn_bits_q <= '0;
           Tests:       T4 T5 T6 
118        1/1              end else if (src_req) begin
           Tests:       T4 T5 T6 
119                           // See assertion below
120                           // At the beginning of a software initiated transaction, the following
121                           // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122                           // change for the duration of the synchronization operation.
123        1/1                src_q <= src_wd_i & BitMask;
           Tests:       T1 T2 T3 
124        1/1                txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
           Tests:       T1 T2 T3 
125        1/1              end else if (src_busy_q && src_ack || src_update && !busy) begin
           Tests:       T4 T5 T6 
126                           // sample data whenever a busy transaction finishes OR
127                           // when an update pulse is seen.
128                           // TODO: We should add a cover group to test different sync timings
129                           // between src_ack and src_update. ie. there can be 3 scenarios:
130                           // 1. update one cycle before ack
131                           // 2. ack one cycle before update
132                           // 3. update / ack on the same cycle
133                           // During all 3 cases the read data should be correct
134        1/1                src_q <= dst_qs;
           Tests:       T1 T2 T3 
135        1/1                txn_bits_q <= '0;
           Tests:       T1 T2 T3 
136                         end
                        MISSING_ELSE
137                       end
138                     
139                       // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140                       // (decoded from address) is busy. So this creates a situation in the current design where
141                       // src_req_i and busy can never be high at the same time.
142                       // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143                       // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144                       // condition cannot be met.
145                       // Thus we add an assertion here to ensure the condition is always satisfied.
146                       `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147                     
148                       // reserved bits are not used
149                       logic unused_wd;
150        1/1            assign unused_wd = ^src_wd_i;
           Tests:       T4 T5 T6 
151                     
152                       // src_q is always updated in the clk_src domain.
153                       // when performing an update to the destination domain, it is guaranteed
154                       // to not change by protocol.
155        1/1            assign src_qs_o = src_q;
           Tests:       T1 T2 T3 
156        1/1            assign dst_wd_o = src_q;
           Tests:       T1 T2 T3 
157                     
158                       ////////////////////////////
159                       // CDC handling
160                       ////////////////////////////
161                     
162                       logic dst_req_from_src;
163                       logic dst_req;
164                     
165                     
166                       // the software transaction is pulse synced across the domain.
167                       // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168                       prim_pulse_sync u_src_to_dst_req (
169                         .clk_src_i,
170                         .rst_src_ni,
171                         .clk_dst_i,
172                         .rst_dst_ni,
173                         .src_pulse_i(src_req),
174                         .dst_pulse_o(dst_req_from_src)
175                       );
176                     
177                       prim_reg_cdc_arb #(
178                         .DataWidth(DataWidth),
179                         .ResetVal(ResetVal),
180                         .DstWrReq(DstWrReq)
181                       ) u_arb (
182                         .clk_src_i,
183                         .rst_src_ni,
184                         .clk_dst_i,
185                         .rst_dst_ni,
186                         .src_ack_o(src_ack),
187                         .src_update_o(src_update),
188                         .dst_req_i(dst_req_from_src),
189                         .dst_req_o(dst_req),
190                         .dst_update_i,
191                         .dst_ds_i,
192                         .dst_qs_i,
193                         .dst_qs_o(dst_qs)
194                       );
195                     
196                     
197                       // Each is valid only when destination request pulse is high; this is important in not propagating
198                       // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199                       // reset.
200        1/1            assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
           Tests:       T1 T2 T3 

---

Cond Coverage for Instance : tb.dut.u_reg.u_usb_meas_ctrl_en_cdc

	Total	Covered	Percent
Conditions	14	12	85.71
Logical	14	12	85.71
Non-Logical	0	0
Event	0	0

 LINE       65
 EXPRESSION (src_we_i | src_re_i)
             ----1---   ----2---

-1-	-2-	Status	Tests
0	0	Covered	T4,T5,T6
0	1	Unreachable
1	0	Covered	T1,T2,T3

 LINE       109
 EXPRESSION (src_busy_q & ((!src_ack)))
             -----1----   ------2-----

-1-	-2-	Status	Tests
0	1	Covered	T4,T5,T6
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

 LINE       125
 EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
             -----------1-----------    ------------2------------

-1-	-2-	Status	Tests
0	0	Covered	T4,T5,T6
0	1	Covered	T2,T10,T11
1	0	Covered	T1,T2,T3

 LINE       125
 SUB-EXPRESSION (src_busy_q && src_ack)
                 -----1----    ---2---

-1-	-2-	Status	Tests
0	1	Not Covered
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

 LINE       125
 SUB-EXPRESSION (src_update && ((!busy)))
                 -----1----    ----2----

-1-	-2-	Status	Tests
0	1	Covered	T4,T5,T6
1	0	Not Covered
1	1	Covered	T2,T10,T11

---

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	39214857	59785	0	0
DstReqKnown_A	44843662	42357384	0	0
SrcAckBusyChk_A	39214857	12088	0	0
SrcBusyKnown_A	39214857	36366002	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	59785	0	0
T1	2920	18	0	0
T2	44895	119	0	0
T3	0	84	0	0
T10	0	107	0	0
T11	0	54	0	0
T19	2130	0	0	0
T20	1318	0	0	0
T27	0	87	0	0
T28	0	178	0	0
T36	0	101	0	0
T44	949	0	0	0
T45	28709	0	0	0
T46	1704	0	0	0
T47	3012	0	0	0
T48	2269	0	0	0
T49	1302	0	0	0
T50	0	151	0	0
T51	0	38	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	44843662	42357384	0	0
T4	1922	1834	0	0
T5	3069	2974	0	0
T6	829	783	0	0
T29	753	631	0	0
T30	1939	1852	0	0
T31	4223	4184	0	0
T32	5997	5882	0	0
T33	970	855	0	0
T34	4380	4279	0	0
T35	3747	3659	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	12088	0	0
T1	2920	5	0	0
T2	44895	36	0	0
T3	0	14	0	0
T10	0	38	0	0
T11	0	8	0	0
T19	2130	0	0	0
T20	1318	0	0	0
T27	0	31	0	0
T28	0	38	0	0
T36	0	14	0	0
T44	949	0	0	0
T45	28709	0	0	0
T46	1704	0	0	0
T47	3012	0	0	0
T48	2269	0	0	0
T49	1302	0	0	0
T50	0	18	0	0
T51	0	10	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	36366002	0	0
T4	1922	1834	0	0
T5	1598	1549	0	0
T6	1727	1630	0	0
T29	1539	1290	0	0
T30	1004	962	0	0
T31	1495	1481	0	0
T32	1873	1837	0	0
T33	2022	1781	0	0
T34	1095	1070	0	0
T35	1717	1677	0	0

Line Coverage for Instance : tb.dut.u_reg.u_io_meas_ctrl_shadowed_cdc

	Line No.	Total	Covered	Percent
TOTAL		22	22	100.00
CONT_ASSIGN	65	1	1	100.00
ALWAYS	71	6	6	100.00
CONT_ASSIGN	85	1	1	100.00
CONT_ASSIGN	109	1	1	100.00
ALWAYS	115	9	9	100.00
CONT_ASSIGN	150	1	1	100.00
CONT_ASSIGN	155	1	1	100.00
CONT_ASSIGN	156	1	1	100.00
CONT_ASSIGN	200	1	1	100.00

64                      
65         1/1            assign src_req = src_we_i | src_re_i;
           Tests:       T1 T2 T3 
66                      
67                        // busy indication back-pressures upstream if the register is accessed
68                        // again.  The busy indication is also used as a "commit" indication for
69                        // resolving software and hardware write conflicts
70                        always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71         1/1              if (!rst_src_ni) begin
           Tests:       T4 T5 T6 
72         1/1                src_busy_q <= '0;
           Tests:       T4 T5 T6 
73         1/1              end else if (src_req) begin
           Tests:       T4 T5 T6 
74         1/1                src_busy_q <= 1'b1;
           Tests:       T1 T2 T3 
75         1/1              end else if (src_ack) begin
           Tests:       T4 T5 T6 
76         1/1                src_busy_q <= 1'b0;
           Tests:       T1 T2 T3 
77                          end
                        MISSING_ELSE
78                        end
79                      
80                        // A src_ack should only be sent if there was a src_req.
81                        // src_busy_q asserts whenever there is a src_req.  By association,
82                        // whenever src_ack is seen, then src_busy must be high.
83                        `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84                      
85         1/1            assign src_busy_o = src_busy_q;
           Tests:       T1 T2 T3 
86                      
87                        // src_q acts as both the write holding register and the software read back
88                        // register.
89                        // When software performs a write, the write data is captured in src_q for
90                        // CDC purposes.  When not performing a write, the src_q reflects the most recent
91                        // hardware value. For registers with no hardware access, this is simply the
92                        // the value programmed by software (or in the case R1C, W1C etc) the value after
93                        // the operation. For registers with hardware access, this reflects a potentially
94                        // delayed version of the real value, as the software facing updates lag real
95                        // time updates.
96                        //
97                        // To resolve software and hardware conflicts, the process is as follows:
98                        // When software issues a write, this module asserts "busy".  While busy,
99                        // src_q does not take on destination value updates.  Since the
100                       // logic has committed to updating based on software command, there is an irreversible
101                       // window from which hardware writes are ignored.  Once the busy window completes,
102                       // the cdc portion then begins sampling once more.
103                       //
104                       // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105                       // software is always prioritized.  The main difference is the conflict resolution window
106                       // is now larger instead of just one destination clock cycle.
107                     
108                       logic busy;
109        1/1            assign busy = src_busy_q & !src_ack;
           Tests:       T1 T2 T3 
110                     
111                       // This is the current destination value
112                       logic [DataWidth-1:0] dst_qs;
113                       logic src_update;
114                       always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115        1/1              if (!rst_src_ni) begin
           Tests:       T4 T5 T6 
116        1/1                src_q <= ResetVal;
           Tests:       T4 T5 T6 
117        1/1                txn_bits_q <= '0;
           Tests:       T4 T5 T6 
118        1/1              end else if (src_req) begin
           Tests:       T4 T5 T6 
119                           // See assertion below
120                           // At the beginning of a software initiated transaction, the following
121                           // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122                           // change for the duration of the synchronization operation.
123        1/1                src_q <= src_wd_i & BitMask;
           Tests:       T1 T2 T3 
124        1/1                txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
           Tests:       T1 T2 T3 
125        1/1              end else if (src_busy_q && src_ack || src_update && !busy) begin
           Tests:       T4 T5 T6 
126                           // sample data whenever a busy transaction finishes OR
127                           // when an update pulse is seen.
128                           // TODO: We should add a cover group to test different sync timings
129                           // between src_ack and src_update. ie. there can be 3 scenarios:
130                           // 1. update one cycle before ack
131                           // 2. ack one cycle before update
132                           // 3. update / ack on the same cycle
133                           // During all 3 cases the read data should be correct
134        1/1                src_q <= dst_qs;
           Tests:       T1 T2 T3 
135        1/1                txn_bits_q <= '0;
           Tests:       T1 T2 T3 
136                         end
                        MISSING_ELSE
137                       end
138                     
139                       // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140                       // (decoded from address) is busy. So this creates a situation in the current design where
141                       // src_req_i and busy can never be high at the same time.
142                       // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143                       // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144                       // condition cannot be met.
145                       // Thus we add an assertion here to ensure the condition is always satisfied.
146                       `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147                     
148                       // reserved bits are not used
149                       logic unused_wd;
150        1/1            assign unused_wd = ^src_wd_i;
           Tests:       T4 T5 T6 
151                     
152                       // src_q is always updated in the clk_src domain.
153                       // when performing an update to the destination domain, it is guaranteed
154                       // to not change by protocol.
155        1/1            assign src_qs_o = src_q;
           Tests:       T1 T2 T3 
156        1/1            assign dst_wd_o = src_q;
           Tests:       T1 T2 T3 
157                     
158                       ////////////////////////////
159                       // CDC handling
160                       ////////////////////////////
161                     
162                       logic dst_req_from_src;
163                       logic dst_req;
164                     
165                     
166                       // the software transaction is pulse synced across the domain.
167                       // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168                       prim_pulse_sync u_src_to_dst_req (
169                         .clk_src_i,
170                         .rst_src_ni,
171                         .clk_dst_i,
172                         .rst_dst_ni,
173                         .src_pulse_i(src_req),
174                         .dst_pulse_o(dst_req_from_src)
175                       );
176                     
177                       prim_reg_cdc_arb #(
178                         .DataWidth(DataWidth),
179                         .ResetVal(ResetVal),
180                         .DstWrReq(DstWrReq)
181                       ) u_arb (
182                         .clk_src_i,
183                         .rst_src_ni,
184                         .clk_dst_i,
185                         .rst_dst_ni,
186                         .src_ack_o(src_ack),
187                         .src_update_o(src_update),
188                         .dst_req_i(dst_req_from_src),
189                         .dst_req_o(dst_req),
190                         .dst_update_i,
191                         .dst_ds_i,
192                         .dst_qs_i,
193                         .dst_qs_o(dst_qs)
194                       );
195                     
196                     
197                       // Each is valid only when destination request pulse is high; this is important in not propagating
198                       // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199                       // reset.
200        1/1            assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
           Tests:       T1 T2 T3 

---

Cond Coverage for Instance : tb.dut.u_reg.u_io_meas_ctrl_shadowed_cdc

	Total	Covered	Percent
Conditions	12	11	91.67
Logical	12	11	91.67
Non-Logical	0	0
Event	0	0

 LINE       65
 EXPRESSION (src_we_i | src_re_i)
             ----1---   ----2---

-1-	-2-	Status	Tests
0	0	Covered	T4,T5,T6
0	1	Covered	T1,T50,T27
1	0	Covered	T1,T2,T3

 LINE       109
 EXPRESSION (src_busy_q & ((!src_ack)))
             -----1----   ------2-----

-1-	-2-	Status	Tests
0	1	Covered	T4,T5,T6
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

 LINE       125
 EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
             -----------1-----------    ------------2------------

-1-	-2-	Status	Tests
0	0	Covered	T4,T5,T6
0	1	Unreachable
1	0	Covered	T1,T2,T3

 LINE       125
 SUB-EXPRESSION (src_busy_q && src_ack)
                 -----1----    ---2---

-1-	-2-	Status	Tests
0	1	Not Covered
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

 LINE       125
 SUB-EXPRESSION (src_update && ((!busy)))
                 -----1----    ----2----

-1-	-2-	Status	Tests
0	1	Covered	T4,T5,T6
1	0	Unreachable
1	1	Unreachable

---

Branch Coverage for Instance : tb.dut.u_reg.u_io_meas_ctrl_shadowed_cdc

	Line No.	Total	Covered	Percent
Branches		8	8	100.00
IF	71	4	4	100.00
IF	115	4	4	100.00

71             if (!rst_src_ni) begin
               -1-  
72               src_busy_q <= '0;
                 ==>
73             end else if (src_req) begin
                        -2-  
74               src_busy_q <= 1'b1;
                 ==>
75             end else if (src_ack) begin
                        -3-  
76               src_busy_q <= 1'b0;
                 ==>
77             end
               MISSING_ELSE
               ==>

Branches:

-1-	-2-	-3-	Status	Tests
1	-	-	Covered	T4,T5,T6
0	1	-	Covered	T1,T2,T3
0	0	1	Covered	T1,T2,T3
0	0	0	Covered	T4,T5,T6

115            if (!rst_src_ni) begin
               -1-  
116              src_q <= ResetVal;
                 ==>
117              txn_bits_q <= '0;
118            end else if (src_req) begin
                        -2-  
119              // See assertion below
120              // At the beginning of a software initiated transaction, the following
121              // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122              // change for the duration of the synchronization operation.
123              src_q <= src_wd_i & BitMask;
                 ==>
124              txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125            end else if (src_busy_q && src_ack || src_update && !busy) begin
                        -3-  
126              // sample data whenever a busy transaction finishes OR
127              // when an update pulse is seen.
128              // TODO: We should add a cover group to test different sync timings
129              // between src_ack and src_update. ie. there can be 3 scenarios:
130              // 1. update one cycle before ack
131              // 2. ack one cycle before update
132              // 3. update / ack on the same cycle
133              // During all 3 cases the read data should be correct
134              src_q <= dst_qs;
                 ==>
135              txn_bits_q <= '0;
136            end
               MISSING_ELSE
               ==>

Branches:

-1-	-2-	-3-	Status	Tests
1	-	-	Covered	T4,T5,T6
0	1	-	Covered	T1,T2,T3
0	0	1	Covered	T1,T2,T3
0	0	0	Covered	T4,T5,T6

---

Assert Coverage for Instance : tb.dut.u_reg.u_io_meas_ctrl_shadowed_cdc

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

---

Assertion Details

Name	Attempts	Real Successes	Failures	Incomplete
BusySrcReqChk_A	39214857	66323	0	0
DstReqKnown_A	84591034	79784677	0	0
SrcAckBusyChk_A	39214857	19191	0	0
SrcBusyKnown_A	39214857	36366002	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	66323	0	0
T1	2920	51	0	0
T2	44895	87	0	0
T3	0	49	0	0
T10	0	94	0	0
T11	0	36	0	0
T19	2130	0	0	0
T20	1318	0	0	0
T27	0	187	0	0
T28	0	128	0	0
T36	0	78	0	0
T44	949	0	0	0
T45	28709	0	0	0
T46	1704	0	0	0
T47	3012	0	0	0
T48	2269	0	0	0
T49	1302	0	0	0
T50	0	132	0	0
T51	0	70	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	84591034	79784677	0	0
T4	3843	3668	0	0
T5	6138	5948	0	0
T6	1659	1565	0	0
T29	1507	1263	0	0
T30	3707	3531	0	0
T31	8447	8367	0	0
T32	11992	11762	0	0
T33	1941	1710	0	0
T34	8759	8556	0	0
T35	7495	7319	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	19191	0	0
T1	2920	20	0	0
T2	44895	36	0	0
T3	0	14	0	0
T10	0	38	0	0
T11	0	8	0	0
T19	2130	0	0	0
T20	1318	0	0	0
T27	0	76	0	0
T28	0	38	0	0
T36	0	14	0	0
T44	949	0	0	0
T45	28709	0	0	0
T46	1704	0	0	0
T47	3012	0	0	0
T48	2269	0	0	0
T49	1302	0	0	0
T50	0	25	0	0
T51	0	28	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	36366002	0	0
T4	1922	1834	0	0
T5	1598	1549	0	0
T6	1727	1630	0	0
T29	1539	1290	0	0
T30	1004	962	0	0
T31	1495	1481	0	0
T32	1873	1837	0	0
T33	2022	1781	0	0
T34	1095	1070	0	0
T35	1717	1677	0	0

Line Coverage for Instance : tb.dut.u_reg.u_io_div2_meas_ctrl_shadowed_cdc

	Line No.	Total	Covered	Percent
TOTAL		22	22	100.00
CONT_ASSIGN	65	1	1	100.00
ALWAYS	71	6	6	100.00
CONT_ASSIGN	85	1	1	100.00
CONT_ASSIGN	109	1	1	100.00
ALWAYS	115	9	9	100.00
CONT_ASSIGN	150	1	1	100.00
CONT_ASSIGN	155	1	1	100.00
CONT_ASSIGN	156	1	1	100.00
CONT_ASSIGN	200	1	1	100.00

64                      
65         1/1            assign src_req = src_we_i | src_re_i;
           Tests:       T1 T2 T3 
66                      
67                        // busy indication back-pressures upstream if the register is accessed
68                        // again.  The busy indication is also used as a "commit" indication for
69                        // resolving software and hardware write conflicts
70                        always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71         1/1              if (!rst_src_ni) begin
           Tests:       T4 T5 T6 
72         1/1                src_busy_q <= '0;
           Tests:       T4 T5 T6 
73         1/1              end else if (src_req) begin
           Tests:       T4 T5 T6 
74         1/1                src_busy_q <= 1'b1;
           Tests:       T1 T2 T3 
75         1/1              end else if (src_ack) begin
           Tests:       T4 T5 T6 
76         1/1                src_busy_q <= 1'b0;
           Tests:       T1 T2 T3 
77                          end
                        MISSING_ELSE
78                        end
79                      
80                        // A src_ack should only be sent if there was a src_req.
81                        // src_busy_q asserts whenever there is a src_req.  By association,
82                        // whenever src_ack is seen, then src_busy must be high.
83                        `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84                      
85         1/1            assign src_busy_o = src_busy_q;
           Tests:       T1 T2 T3 
86                      
87                        // src_q acts as both the write holding register and the software read back
88                        // register.
89                        // When software performs a write, the write data is captured in src_q for
90                        // CDC purposes.  When not performing a write, the src_q reflects the most recent
91                        // hardware value. For registers with no hardware access, this is simply the
92                        // the value programmed by software (or in the case R1C, W1C etc) the value after
93                        // the operation. For registers with hardware access, this reflects a potentially
94                        // delayed version of the real value, as the software facing updates lag real
95                        // time updates.
96                        //
97                        // To resolve software and hardware conflicts, the process is as follows:
98                        // When software issues a write, this module asserts "busy".  While busy,
99                        // src_q does not take on destination value updates.  Since the
100                       // logic has committed to updating based on software command, there is an irreversible
101                       // window from which hardware writes are ignored.  Once the busy window completes,
102                       // the cdc portion then begins sampling once more.
103                       //
104                       // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105                       // software is always prioritized.  The main difference is the conflict resolution window
106                       // is now larger instead of just one destination clock cycle.
107                     
108                       logic busy;
109        1/1            assign busy = src_busy_q & !src_ack;
           Tests:       T1 T2 T3 
110                     
111                       // This is the current destination value
112                       logic [DataWidth-1:0] dst_qs;
113                       logic src_update;
114                       always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115        1/1              if (!rst_src_ni) begin
           Tests:       T4 T5 T6 
116        1/1                src_q <= ResetVal;
           Tests:       T4 T5 T6 
117        1/1                txn_bits_q <= '0;
           Tests:       T4 T5 T6 
118        1/1              end else if (src_req) begin
           Tests:       T4 T5 T6 
119                           // See assertion below
120                           // At the beginning of a software initiated transaction, the following
121                           // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122                           // change for the duration of the synchronization operation.
123        1/1                src_q <= src_wd_i & BitMask;
           Tests:       T1 T2 T3 
124        1/1                txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
           Tests:       T1 T2 T3 
125        1/1              end else if (src_busy_q && src_ack || src_update && !busy) begin
           Tests:       T4 T5 T6 
126                           // sample data whenever a busy transaction finishes OR
127                           // when an update pulse is seen.
128                           // TODO: We should add a cover group to test different sync timings
129                           // between src_ack and src_update. ie. there can be 3 scenarios:
130                           // 1. update one cycle before ack
131                           // 2. ack one cycle before update
132                           // 3. update / ack on the same cycle
133                           // During all 3 cases the read data should be correct
134        1/1                src_q <= dst_qs;
           Tests:       T1 T2 T3 
135        1/1                txn_bits_q <= '0;
           Tests:       T1 T2 T3 
136                         end
                        MISSING_ELSE
137                       end
138                     
139                       // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140                       // (decoded from address) is busy. So this creates a situation in the current design where
141                       // src_req_i and busy can never be high at the same time.
142                       // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143                       // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144                       // condition cannot be met.
145                       // Thus we add an assertion here to ensure the condition is always satisfied.
146                       `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147                     
148                       // reserved bits are not used
149                       logic unused_wd;
150        1/1            assign unused_wd = ^src_wd_i;
           Tests:       T4 T5 T6 
151                     
152                       // src_q is always updated in the clk_src domain.
153                       // when performing an update to the destination domain, it is guaranteed
154                       // to not change by protocol.
155        1/1            assign src_qs_o = src_q;
           Tests:       T1 T2 T3 
156        1/1            assign dst_wd_o = src_q;
           Tests:       T1 T2 T3 
157                     
158                       ////////////////////////////
159                       // CDC handling
160                       ////////////////////////////
161                     
162                       logic dst_req_from_src;
163                       logic dst_req;
164                     
165                     
166                       // the software transaction is pulse synced across the domain.
167                       // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168                       prim_pulse_sync u_src_to_dst_req (
169                         .clk_src_i,
170                         .rst_src_ni,
171                         .clk_dst_i,
172                         .rst_dst_ni,
173                         .src_pulse_i(src_req),
174                         .dst_pulse_o(dst_req_from_src)
175                       );
176                     
177                       prim_reg_cdc_arb #(
178                         .DataWidth(DataWidth),
179                         .ResetVal(ResetVal),
180                         .DstWrReq(DstWrReq)
181                       ) u_arb (
182                         .clk_src_i,
183                         .rst_src_ni,
184                         .clk_dst_i,
185                         .rst_dst_ni,
186                         .src_ack_o(src_ack),
187                         .src_update_o(src_update),
188                         .dst_req_i(dst_req_from_src),
189                         .dst_req_o(dst_req),
190                         .dst_update_i,
191                         .dst_ds_i,
192                         .dst_qs_i,
193                         .dst_qs_o(dst_qs)
194                       );
195                     
196                     
197                       // Each is valid only when destination request pulse is high; this is important in not propagating
198                       // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199                       // reset.
200        1/1            assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
           Tests:       T1 T2 T3 

---

Cond Coverage for Instance : tb.dut.u_reg.u_io_div2_meas_ctrl_shadowed_cdc

	Total	Covered	Percent
Conditions	12	11	91.67
Logical	12	11	91.67
Non-Logical	0	0
Event	0	0

 LINE       65
 EXPRESSION (src_we_i | src_re_i)
             ----1---   ----2---

-1-	-2-	Status	Tests
0	0	Covered	T4,T5,T6
0	1	Covered	T1,T50,T27
1	0	Covered	T1,T2,T3

 LINE       109
 EXPRESSION (src_busy_q & ((!src_ack)))
             -----1----   ------2-----

-1-	-2-	Status	Tests
0	1	Covered	T4,T5,T6
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

 LINE       125
 EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
             -----------1-----------    ------------2------------

-1-	-2-	Status	Tests
0	0	Covered	T4,T5,T6
0	1	Unreachable
1	0	Covered	T1,T2,T3

 LINE       125
 SUB-EXPRESSION (src_busy_q && src_ack)
                 -----1----    ---2---

-1-	-2-	Status	Tests
0	1	Not Covered
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

 LINE       125
 SUB-EXPRESSION (src_update && ((!busy)))
                 -----1----    ----2----

-1-	-2-	Status	Tests
0	1	Covered	T4,T5,T6
1	0	Unreachable
1	1	Unreachable

---

Branch Coverage for Instance : tb.dut.u_reg.u_io_div2_meas_ctrl_shadowed_cdc

	Line No.	Total	Covered	Percent
Branches		8	8	100.00
IF	71	4	4	100.00
IF	115	4	4	100.00

71             if (!rst_src_ni) begin
               -1-  
72               src_busy_q <= '0;
                 ==>
73             end else if (src_req) begin
                        -2-  
74               src_busy_q <= 1'b1;
                 ==>
75             end else if (src_ack) begin
                        -3-  
76               src_busy_q <= 1'b0;
                 ==>
77             end
               MISSING_ELSE
               ==>

Branches:

-1-	-2-	-3-	Status	Tests
1	-	-	Covered	T4,T5,T6
0	1	-	Covered	T1,T2,T3
0	0	1	Covered	T1,T2,T3
0	0	0	Covered	T4,T5,T6

115            if (!rst_src_ni) begin
               -1-  
116              src_q <= ResetVal;
                 ==>
117              txn_bits_q <= '0;
118            end else if (src_req) begin
                        -2-  
119              // See assertion below
120              // At the beginning of a software initiated transaction, the following
121              // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122              // change for the duration of the synchronization operation.
123              src_q <= src_wd_i & BitMask;
                 ==>
124              txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125            end else if (src_busy_q && src_ack || src_update && !busy) begin
                        -3-  
126              // sample data whenever a busy transaction finishes OR
127              // when an update pulse is seen.
128              // TODO: We should add a cover group to test different sync timings
129              // between src_ack and src_update. ie. there can be 3 scenarios:
130              // 1. update one cycle before ack
131              // 2. ack one cycle before update
132              // 3. update / ack on the same cycle
133              // During all 3 cases the read data should be correct
134              src_q <= dst_qs;
                 ==>
135              txn_bits_q <= '0;
136            end
               MISSING_ELSE
               ==>

Branches:

-1-	-2-	-3-	Status	Tests
1	-	-	Covered	T4,T5,T6
0	1	-	Covered	T1,T2,T3
0	0	1	Covered	T1,T2,T3
0	0	0	Covered	T4,T5,T6

---

Assert Coverage for Instance : tb.dut.u_reg.u_io_div2_meas_ctrl_shadowed_cdc

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

---

Assertion Details

Name	Attempts	Real Successes	Failures	Incomplete
BusySrcReqChk_A	39214857	93821	0	0
DstReqKnown_A	41278982	40071537	0	0
SrcAckBusyChk_A	39214857	19169	0	0
SrcBusyKnown_A	39214857	36366002	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	93821	0	0
T1	2920	51	0	0
T2	44895	117	0	0
T3	0	70	0	0
T10	0	109	0	0
T11	0	56	0	0
T19	2130	0	0	0
T20	1318	0	0	0
T27	0	187	0	0
T28	0	181	0	0
T36	0	113	0	0
T44	949	0	0	0
T45	28709	0	0	0
T46	1704	0	0	0
T47	3012	0	0	0
T48	2269	0	0	0
T49	1302	0	0	0
T50	0	217	0	0
T51	0	93	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	41278982	40071537	0	0
T4	1903	1834	0	0
T5	3321	3280	0	0
T6	796	782	0	0
T29	700	631	0	0
T30	1821	1766	0	0
T31	4197	4183	0	0
T32	6732	6663	0	0
T33	978	909	0	0
T34	7568	7527	0	0
T35	4351	4289	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	19169	0	0
T1	2920	20	0	0
T2	44895	36	0	0
T3	0	14	0	0
T10	0	38	0	0
T11	0	8	0	0
T19	2130	0	0	0
T20	1318	0	0	0
T27	0	76	0	0
T28	0	38	0	0
T36	0	14	0	0
T44	949	0	0	0
T45	28709	0	0	0
T46	1704	0	0	0
T47	3012	0	0	0
T48	2269	0	0	0
T49	1302	0	0	0
T50	0	25	0	0
T51	0	28	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	36366002	0	0
T4	1922	1834	0	0
T5	1598	1549	0	0
T6	1727	1630	0	0
T29	1539	1290	0	0
T30	1004	962	0	0
T31	1495	1481	0	0
T32	1873	1837	0	0
T33	2022	1781	0	0
T34	1095	1070	0	0
T35	1717	1677	0	0

Line Coverage for Instance : tb.dut.u_reg.u_io_div4_meas_ctrl_shadowed_cdc

	Line No.	Total	Covered	Percent
TOTAL		22	22	100.00
CONT_ASSIGN	65	1	1	100.00
ALWAYS	71	6	6	100.00
CONT_ASSIGN	85	1	1	100.00
CONT_ASSIGN	109	1	1	100.00
ALWAYS	115	9	9	100.00
CONT_ASSIGN	150	1	1	100.00
CONT_ASSIGN	155	1	1	100.00
CONT_ASSIGN	156	1	1	100.00
CONT_ASSIGN	200	1	1	100.00

64                      
65         1/1            assign src_req = src_we_i | src_re_i;
           Tests:       T1 T2 T3 
66                      
67                        // busy indication back-pressures upstream if the register is accessed
68                        // again.  The busy indication is also used as a "commit" indication for
69                        // resolving software and hardware write conflicts
70                        always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71         1/1              if (!rst_src_ni) begin
           Tests:       T4 T5 T6 
72         1/1                src_busy_q <= '0;
           Tests:       T4 T5 T6 
73         1/1              end else if (src_req) begin
           Tests:       T4 T5 T6 
74         1/1                src_busy_q <= 1'b1;
           Tests:       T1 T2 T3 
75         1/1              end else if (src_ack) begin
           Tests:       T4 T5 T6 
76         1/1                src_busy_q <= 1'b0;
           Tests:       T1 T2 T3 
77                          end
                        MISSING_ELSE
78                        end
79                      
80                        // A src_ack should only be sent if there was a src_req.
81                        // src_busy_q asserts whenever there is a src_req.  By association,
82                        // whenever src_ack is seen, then src_busy must be high.
83                        `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84                      
85         1/1            assign src_busy_o = src_busy_q;
           Tests:       T1 T2 T3 
86                      
87                        // src_q acts as both the write holding register and the software read back
88                        // register.
89                        // When software performs a write, the write data is captured in src_q for
90                        // CDC purposes.  When not performing a write, the src_q reflects the most recent
91                        // hardware value. For registers with no hardware access, this is simply the
92                        // the value programmed by software (or in the case R1C, W1C etc) the value after
93                        // the operation. For registers with hardware access, this reflects a potentially
94                        // delayed version of the real value, as the software facing updates lag real
95                        // time updates.
96                        //
97                        // To resolve software and hardware conflicts, the process is as follows:
98                        // When software issues a write, this module asserts "busy".  While busy,
99                        // src_q does not take on destination value updates.  Since the
100                       // logic has committed to updating based on software command, there is an irreversible
101                       // window from which hardware writes are ignored.  Once the busy window completes,
102                       // the cdc portion then begins sampling once more.
103                       //
104                       // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105                       // software is always prioritized.  The main difference is the conflict resolution window
106                       // is now larger instead of just one destination clock cycle.
107                     
108                       logic busy;
109        1/1            assign busy = src_busy_q & !src_ack;
           Tests:       T1 T2 T3 
110                     
111                       // This is the current destination value
112                       logic [DataWidth-1:0] dst_qs;
113                       logic src_update;
114                       always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115        1/1              if (!rst_src_ni) begin
           Tests:       T4 T5 T6 
116        1/1                src_q <= ResetVal;
           Tests:       T4 T5 T6 
117        1/1                txn_bits_q <= '0;
           Tests:       T4 T5 T6 
118        1/1              end else if (src_req) begin
           Tests:       T4 T5 T6 
119                           // See assertion below
120                           // At the beginning of a software initiated transaction, the following
121                           // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122                           // change for the duration of the synchronization operation.
123        1/1                src_q <= src_wd_i & BitMask;
           Tests:       T1 T2 T3 
124        1/1                txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
           Tests:       T1 T2 T3 
125        1/1              end else if (src_busy_q && src_ack || src_update && !busy) begin
           Tests:       T4 T5 T6 
126                           // sample data whenever a busy transaction finishes OR
127                           // when an update pulse is seen.
128                           // TODO: We should add a cover group to test different sync timings
129                           // between src_ack and src_update. ie. there can be 3 scenarios:
130                           // 1. update one cycle before ack
131                           // 2. ack one cycle before update
132                           // 3. update / ack on the same cycle
133                           // During all 3 cases the read data should be correct
134        1/1                src_q <= dst_qs;
           Tests:       T1 T2 T3 
135        1/1                txn_bits_q <= '0;
           Tests:       T1 T2 T3 
136                         end
                        MISSING_ELSE
137                       end
138                     
139                       // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140                       // (decoded from address) is busy. So this creates a situation in the current design where
141                       // src_req_i and busy can never be high at the same time.
142                       // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143                       // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144                       // condition cannot be met.
145                       // Thus we add an assertion here to ensure the condition is always satisfied.
146                       `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147                     
148                       // reserved bits are not used
149                       logic unused_wd;
150        1/1            assign unused_wd = ^src_wd_i;
           Tests:       T4 T5 T6 
151                     
152                       // src_q is always updated in the clk_src domain.
153                       // when performing an update to the destination domain, it is guaranteed
154                       // to not change by protocol.
155        1/1            assign src_qs_o = src_q;
           Tests:       T1 T2 T3 
156        1/1            assign dst_wd_o = src_q;
           Tests:       T1 T2 T3 
157                     
158                       ////////////////////////////
159                       // CDC handling
160                       ////////////////////////////
161                     
162                       logic dst_req_from_src;
163                       logic dst_req;
164                     
165                     
166                       // the software transaction is pulse synced across the domain.
167                       // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168                       prim_pulse_sync u_src_to_dst_req (
169                         .clk_src_i,
170                         .rst_src_ni,
171                         .clk_dst_i,
172                         .rst_dst_ni,
173                         .src_pulse_i(src_req),
174                         .dst_pulse_o(dst_req_from_src)
175                       );
176                     
177                       prim_reg_cdc_arb #(
178                         .DataWidth(DataWidth),
179                         .ResetVal(ResetVal),
180                         .DstWrReq(DstWrReq)
181                       ) u_arb (
182                         .clk_src_i,
183                         .rst_src_ni,
184                         .clk_dst_i,
185                         .rst_dst_ni,
186                         .src_ack_o(src_ack),
187                         .src_update_o(src_update),
188                         .dst_req_i(dst_req_from_src),
189                         .dst_req_o(dst_req),
190                         .dst_update_i,
191                         .dst_ds_i,
192                         .dst_qs_i,
193                         .dst_qs_o(dst_qs)
194                       );
195                     
196                     
197                       // Each is valid only when destination request pulse is high; this is important in not propagating
198                       // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199                       // reset.
200        1/1            assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
           Tests:       T1 T2 T3 

---

Cond Coverage for Instance : tb.dut.u_reg.u_io_div4_meas_ctrl_shadowed_cdc

	Total	Covered	Percent
Conditions	12	11	91.67
Logical	12	11	91.67
Non-Logical	0	0
Event	0	0

 LINE       65
 EXPRESSION (src_we_i | src_re_i)
             ----1---   ----2---

-1-	-2-	Status	Tests
0	0	Covered	T4,T5,T6
0	1	Covered	T1,T50,T27
1	0	Covered	T1,T2,T3

 LINE       109
 EXPRESSION (src_busy_q & ((!src_ack)))
             -----1----   ------2-----

-1-	-2-	Status	Tests
0	1	Covered	T4,T5,T6
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

 LINE       125
 EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
             -----------1-----------    ------------2------------

-1-	-2-	Status	Tests
0	0	Covered	T4,T5,T6
0	1	Unreachable
1	0	Covered	T1,T2,T3

 LINE       125
 SUB-EXPRESSION (src_busy_q && src_ack)
                 -----1----    ---2---

-1-	-2-	Status	Tests
0	1	Not Covered
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

 LINE       125
 SUB-EXPRESSION (src_update && ((!busy)))
                 -----1----    ----2----

-1-	-2-	Status	Tests
0	1	Covered	T4,T5,T6
1	0	Unreachable
1	1	Unreachable

---

Branch Coverage for Instance : tb.dut.u_reg.u_io_div4_meas_ctrl_shadowed_cdc

	Line No.	Total	Covered	Percent
Branches		8	8	100.00
IF	71	4	4	100.00
IF	115	4	4	100.00

71             if (!rst_src_ni) begin
               -1-  
72               src_busy_q <= '0;
                 ==>
73             end else if (src_req) begin
                        -2-  
74               src_busy_q <= 1'b1;
                 ==>
75             end else if (src_ack) begin
                        -3-  
76               src_busy_q <= 1'b0;
                 ==>
77             end
               MISSING_ELSE
               ==>

Branches:

-1-	-2-	-3-	Status	Tests
1	-	-	Covered	T4,T5,T6
0	1	-	Covered	T1,T2,T3
0	0	1	Covered	T1,T2,T3
0	0	0	Covered	T4,T5,T6

115            if (!rst_src_ni) begin
               -1-  
116              src_q <= ResetVal;
                 ==>
117              txn_bits_q <= '0;
118            end else if (src_req) begin
                        -2-  
119              // See assertion below
120              // At the beginning of a software initiated transaction, the following
121              // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122              // change for the duration of the synchronization operation.
123              src_q <= src_wd_i & BitMask;
                 ==>
124              txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125            end else if (src_busy_q && src_ack || src_update && !busy) begin
                        -3-  
126              // sample data whenever a busy transaction finishes OR
127              // when an update pulse is seen.
128              // TODO: We should add a cover group to test different sync timings
129              // between src_ack and src_update. ie. there can be 3 scenarios:
130              // 1. update one cycle before ack
131              // 2. ack one cycle before update
132              // 3. update / ack on the same cycle
133              // During all 3 cases the read data should be correct
134              src_q <= dst_qs;
                 ==>
135              txn_bits_q <= '0;
136            end
               MISSING_ELSE
               ==>

Branches:

-1-	-2-	-3-	Status	Tests
1	-	-	Covered	T4,T5,T6
0	1	-	Covered	T1,T2,T3
0	0	1	Covered	T1,T2,T3
0	0	0	Covered	T4,T5,T6

---

Assert Coverage for Instance : tb.dut.u_reg.u_io_div4_meas_ctrl_shadowed_cdc

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

---

Assertion Details

Name	Attempts	Real Successes	Failures	Incomplete
BusySrcReqChk_A	39214857	149923	0	0
DstReqKnown_A	20639099	20035472	0	0
SrcAckBusyChk_A	39214857	19153	0	0
SrcBusyKnown_A	39214857	36366002	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	149923	0	0
T1	2920	51	0	0
T2	44895	164	0	0
T3	0	116	0	0
T10	0	147	0	0
T11	0	97	0	0
T19	2130	0	0	0
T20	1318	0	0	0
T27	0	258	0	0
T28	0	287	0	0
T36	0	189	0	0
T44	949	0	0	0
T45	28709	0	0	0
T46	1704	0	0	0
T47	3012	0	0	0
T48	2269	0	0	0
T49	1302	0	0	0
T50	0	368	0	0
T51	0	125	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	20639099	20035472	0	0
T4	951	917	0	0
T5	1661	1640	0	0
T6	398	391	0	0
T29	350	316	0	0
T30	910	882	0	0
T31	2099	2092	0	0
T32	3365	3331	0	0
T33	489	455	0	0
T34	3784	3763	0	0
T35	2173	2142	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	19153	0	0
T1	2920	20	0	0
T2	44895	36	0	0
T3	0	14	0	0
T10	0	38	0	0
T11	0	8	0	0
T19	2130	0	0	0
T20	1318	0	0	0
T27	0	76	0	0
T28	0	38	0	0
T36	0	14	0	0
T44	949	0	0	0
T45	28709	0	0	0
T46	1704	0	0	0
T47	3012	0	0	0
T48	2269	0	0	0
T49	1302	0	0	0
T50	0	25	0	0
T51	0	28	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	36366002	0	0
T4	1922	1834	0	0
T5	1598	1549	0	0
T6	1727	1630	0	0
T29	1539	1290	0	0
T30	1004	962	0	0
T31	1495	1481	0	0
T32	1873	1837	0	0
T33	2022	1781	0	0
T34	1095	1070	0	0
T35	1717	1677	0	0

Line Coverage for Instance : tb.dut.u_reg.u_main_meas_ctrl_shadowed_cdc

	Line No.	Total	Covered	Percent
TOTAL		22	22	100.00
CONT_ASSIGN	65	1	1	100.00
ALWAYS	71	6	6	100.00
CONT_ASSIGN	85	1	1	100.00
CONT_ASSIGN	109	1	1	100.00
ALWAYS	115	9	9	100.00
CONT_ASSIGN	150	1	1	100.00
CONT_ASSIGN	155	1	1	100.00
CONT_ASSIGN	156	1	1	100.00
CONT_ASSIGN	200	1	1	100.00

64                      
65         1/1            assign src_req = src_we_i | src_re_i;
           Tests:       T1 T2 T3 
66                      
67                        // busy indication back-pressures upstream if the register is accessed
68                        // again.  The busy indication is also used as a "commit" indication for
69                        // resolving software and hardware write conflicts
70                        always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71         1/1              if (!rst_src_ni) begin
           Tests:       T4 T5 T6 
72         1/1                src_busy_q <= '0;
           Tests:       T4 T5 T6 
73         1/1              end else if (src_req) begin
           Tests:       T4 T5 T6 
74         1/1                src_busy_q <= 1'b1;
           Tests:       T1 T2 T3 
75         1/1              end else if (src_ack) begin
           Tests:       T4 T5 T6 
76         1/1                src_busy_q <= 1'b0;
           Tests:       T1 T2 T3 
77                          end
                        MISSING_ELSE
78                        end
79                      
80                        // A src_ack should only be sent if there was a src_req.
81                        // src_busy_q asserts whenever there is a src_req.  By association,
82                        // whenever src_ack is seen, then src_busy must be high.
83                        `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84                      
85         1/1            assign src_busy_o = src_busy_q;
           Tests:       T1 T2 T3 
86                      
87                        // src_q acts as both the write holding register and the software read back
88                        // register.
89                        // When software performs a write, the write data is captured in src_q for
90                        // CDC purposes.  When not performing a write, the src_q reflects the most recent
91                        // hardware value. For registers with no hardware access, this is simply the
92                        // the value programmed by software (or in the case R1C, W1C etc) the value after
93                        // the operation. For registers with hardware access, this reflects a potentially
94                        // delayed version of the real value, as the software facing updates lag real
95                        // time updates.
96                        //
97                        // To resolve software and hardware conflicts, the process is as follows:
98                        // When software issues a write, this module asserts "busy".  While busy,
99                        // src_q does not take on destination value updates.  Since the
100                       // logic has committed to updating based on software command, there is an irreversible
101                       // window from which hardware writes are ignored.  Once the busy window completes,
102                       // the cdc portion then begins sampling once more.
103                       //
104                       // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105                       // software is always prioritized.  The main difference is the conflict resolution window
106                       // is now larger instead of just one destination clock cycle.
107                     
108                       logic busy;
109        1/1            assign busy = src_busy_q & !src_ack;
           Tests:       T1 T2 T3 
110                     
111                       // This is the current destination value
112                       logic [DataWidth-1:0] dst_qs;
113                       logic src_update;
114                       always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115        1/1              if (!rst_src_ni) begin
           Tests:       T4 T5 T6 
116        1/1                src_q <= ResetVal;
           Tests:       T4 T5 T6 
117        1/1                txn_bits_q <= '0;
           Tests:       T4 T5 T6 
118        1/1              end else if (src_req) begin
           Tests:       T4 T5 T6 
119                           // See assertion below
120                           // At the beginning of a software initiated transaction, the following
121                           // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122                           // change for the duration of the synchronization operation.
123        1/1                src_q <= src_wd_i & BitMask;
           Tests:       T1 T2 T3 
124        1/1                txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
           Tests:       T1 T2 T3 
125        1/1              end else if (src_busy_q && src_ack || src_update && !busy) begin
           Tests:       T4 T5 T6 
126                           // sample data whenever a busy transaction finishes OR
127                           // when an update pulse is seen.
128                           // TODO: We should add a cover group to test different sync timings
129                           // between src_ack and src_update. ie. there can be 3 scenarios:
130                           // 1. update one cycle before ack
131                           // 2. ack one cycle before update
132                           // 3. update / ack on the same cycle
133                           // During all 3 cases the read data should be correct
134        1/1                src_q <= dst_qs;
           Tests:       T1 T2 T3 
135        1/1                txn_bits_q <= '0;
           Tests:       T1 T2 T3 
136                         end
                        MISSING_ELSE
137                       end
138                     
139                       // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140                       // (decoded from address) is busy. So this creates a situation in the current design where
141                       // src_req_i and busy can never be high at the same time.
142                       // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143                       // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144                       // condition cannot be met.
145                       // Thus we add an assertion here to ensure the condition is always satisfied.
146                       `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147                     
148                       // reserved bits are not used
149                       logic unused_wd;
150        1/1            assign unused_wd = ^src_wd_i;
           Tests:       T4 T5 T6 
151                     
152                       // src_q is always updated in the clk_src domain.
153                       // when performing an update to the destination domain, it is guaranteed
154                       // to not change by protocol.
155        1/1            assign src_qs_o = src_q;
           Tests:       T1 T2 T3 
156        1/1            assign dst_wd_o = src_q;
           Tests:       T1 T2 T3 
157                     
158                       ////////////////////////////
159                       // CDC handling
160                       ////////////////////////////
161                     
162                       logic dst_req_from_src;
163                       logic dst_req;
164                     
165                     
166                       // the software transaction is pulse synced across the domain.
167                       // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168                       prim_pulse_sync u_src_to_dst_req (
169                         .clk_src_i,
170                         .rst_src_ni,
171                         .clk_dst_i,
172                         .rst_dst_ni,
173                         .src_pulse_i(src_req),
174                         .dst_pulse_o(dst_req_from_src)
175                       );
176                     
177                       prim_reg_cdc_arb #(
178                         .DataWidth(DataWidth),
179                         .ResetVal(ResetVal),
180                         .DstWrReq(DstWrReq)
181                       ) u_arb (
182                         .clk_src_i,
183                         .rst_src_ni,
184                         .clk_dst_i,
185                         .rst_dst_ni,
186                         .src_ack_o(src_ack),
187                         .src_update_o(src_update),
188                         .dst_req_i(dst_req_from_src),
189                         .dst_req_o(dst_req),
190                         .dst_update_i,
191                         .dst_ds_i,
192                         .dst_qs_i,
193                         .dst_qs_o(dst_qs)
194                       );
195                     
196                     
197                       // Each is valid only when destination request pulse is high; this is important in not propagating
198                       // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199                       // reset.
200        1/1            assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
           Tests:       T1 T2 T3 

---

Cond Coverage for Instance : tb.dut.u_reg.u_main_meas_ctrl_shadowed_cdc

	Total	Covered	Percent
Conditions	12	11	91.67
Logical	12	11	91.67
Non-Logical	0	0
Event	0	0

 LINE       65
 EXPRESSION (src_we_i | src_re_i)
             ----1---   ----2---

-1-	-2-	Status	Tests
0	0	Covered	T4,T5,T6
0	1	Covered	T1,T50,T27
1	0	Covered	T1,T2,T3

 LINE       109
 EXPRESSION (src_busy_q & ((!src_ack)))
             -----1----   ------2-----

-1-	-2-	Status	Tests
0	1	Covered	T4,T5,T6
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

 LINE       125
 EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
             -----------1-----------    ------------2------------

-1-	-2-	Status	Tests
0	0	Covered	T4,T5,T6
0	1	Unreachable
1	0	Covered	T1,T2,T3

 LINE       125
 SUB-EXPRESSION (src_busy_q && src_ack)
                 -----1----    ---2---

-1-	-2-	Status	Tests
0	1	Not Covered
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

 LINE       125
 SUB-EXPRESSION (src_update && ((!busy)))
                 -----1----    ----2----

-1-	-2-	Status	Tests
0	1	Covered	T4,T5,T6
1	0	Unreachable
1	1	Unreachable

---

Branch Coverage for Instance : tb.dut.u_reg.u_main_meas_ctrl_shadowed_cdc

	Line No.	Total	Covered	Percent
Branches		8	8	100.00
IF	71	4	4	100.00
IF	115	4	4	100.00

71             if (!rst_src_ni) begin
               -1-  
72               src_busy_q <= '0;
                 ==>
73             end else if (src_req) begin
                        -2-  
74               src_busy_q <= 1'b1;
                 ==>
75             end else if (src_ack) begin
                        -3-  
76               src_busy_q <= 1'b0;
                 ==>
77             end
               MISSING_ELSE
               ==>

Branches:

-1-	-2-	-3-	Status	Tests
1	-	-	Covered	T4,T5,T6
0	1	-	Covered	T1,T2,T3
0	0	1	Covered	T1,T2,T3
0	0	0	Covered	T4,T5,T6

115            if (!rst_src_ni) begin
               -1-  
116              src_q <= ResetVal;
                 ==>
117              txn_bits_q <= '0;
118            end else if (src_req) begin
                        -2-  
119              // See assertion below
120              // At the beginning of a software initiated transaction, the following
121              // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122              // change for the duration of the synchronization operation.
123              src_q <= src_wd_i & BitMask;
                 ==>
124              txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125            end else if (src_busy_q && src_ack || src_update && !busy) begin
                        -3-  
126              // sample data whenever a busy transaction finishes OR
127              // when an update pulse is seen.
128              // TODO: We should add a cover group to test different sync timings
129              // between src_ack and src_update. ie. there can be 3 scenarios:
130              // 1. update one cycle before ack
131              // 2. ack one cycle before update
132              // 3. update / ack on the same cycle
133              // During all 3 cases the read data should be correct
134              src_q <= dst_qs;
                 ==>
135              txn_bits_q <= '0;
136            end
               MISSING_ELSE
               ==>

Branches:

-1-	-2-	-3-	Status	Tests
1	-	-	Covered	T4,T5,T6
0	1	-	Covered	T1,T2,T3
0	0	1	Covered	T1,T2,T3
0	0	0	Covered	T4,T5,T6

---

Assert Coverage for Instance : tb.dut.u_reg.u_main_meas_ctrl_shadowed_cdc

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

---

Assertion Details

Name	Attempts	Real Successes	Failures	Incomplete
BusySrcReqChk_A	39214857	65542	0	0
DstReqKnown_A	93466052	88294483	0	0
SrcAckBusyChk_A	39214857	19060	0	0
SrcBusyKnown_A	39214857	36366002	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	65542	0	0
T1	2920	51	0	0
T2	44895	87	0	0
T3	0	49	0	0
T10	0	94	0	0
T11	0	35	0	0
T19	2130	0	0	0
T20	1318	0	0	0
T27	0	187	0	0
T28	0	126	0	0
T36	0	63	0	0
T44	949	0	0	0
T45	28709	0	0	0
T46	1704	0	0	0
T47	3012	0	0	0
T48	2269	0	0	0
T49	1302	0	0	0
T50	0	155	0	0
T51	0	70	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	93466052	88294483	0	0
T4	4004	3821	0	0
T5	6393	6196	0	0
T6	1727	1630	0	0
T29	1570	1315	0	0
T30	3604	3420	0	0
T31	8799	8716	0	0
T32	12493	12253	0	0
T33	2022	1781	0	0
T34	9125	8913	0	0
T35	7808	7625	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	19060	0	0
T1	2920	20	0	0
T2	44895	36	0	0
T3	0	14	0	0
T10	0	38	0	0
T11	0	8	0	0
T19	2130	0	0	0
T20	1318	0	0	0
T27	0	76	0	0
T28	0	38	0	0
T36	0	14	0	0
T44	949	0	0	0
T45	28709	0	0	0
T46	1704	0	0	0
T47	3012	0	0	0
T48	2269	0	0	0
T49	1302	0	0	0
T50	0	25	0	0
T51	0	28	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	36366002	0	0
T4	1922	1834	0	0
T5	1598	1549	0	0
T6	1727	1630	0	0
T29	1539	1290	0	0
T30	1004	962	0	0
T31	1495	1481	0	0
T32	1873	1837	0	0
T33	2022	1781	0	0
T34	1095	1070	0	0
T35	1717	1677	0	0

Line Coverage for Instance : tb.dut.u_reg.u_usb_meas_ctrl_shadowed_cdc

	Line No.	Total	Covered	Percent
TOTAL		22	22	100.00
CONT_ASSIGN	65	1	1	100.00
ALWAYS	71	6	6	100.00
CONT_ASSIGN	85	1	1	100.00
CONT_ASSIGN	109	1	1	100.00
ALWAYS	115	9	9	100.00
CONT_ASSIGN	150	1	1	100.00
CONT_ASSIGN	155	1	1	100.00
CONT_ASSIGN	156	1	1	100.00
CONT_ASSIGN	200	1	1	100.00

64                      
65         1/1            assign src_req = src_we_i | src_re_i;
           Tests:       T1 T2 T3 
66                      
67                        // busy indication back-pressures upstream if the register is accessed
68                        // again.  The busy indication is also used as a "commit" indication for
69                        // resolving software and hardware write conflicts
70                        always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
71         1/1              if (!rst_src_ni) begin
           Tests:       T4 T5 T6 
72         1/1                src_busy_q <= '0;
           Tests:       T4 T5 T6 
73         1/1              end else if (src_req) begin
           Tests:       T4 T5 T6 
74         1/1                src_busy_q <= 1'b1;
           Tests:       T1 T2 T3 
75         1/1              end else if (src_ack) begin
           Tests:       T4 T5 T6 
76         1/1                src_busy_q <= 1'b0;
           Tests:       T1 T2 T3 
77                          end
                        MISSING_ELSE
78                        end
79                      
80                        // A src_ack should only be sent if there was a src_req.
81                        // src_busy_q asserts whenever there is a src_req.  By association,
82                        // whenever src_ack is seen, then src_busy must be high.
83                        `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84                      
85         1/1            assign src_busy_o = src_busy_q;
           Tests:       T1 T2 T3 
86                      
87                        // src_q acts as both the write holding register and the software read back
88                        // register.
89                        // When software performs a write, the write data is captured in src_q for
90                        // CDC purposes.  When not performing a write, the src_q reflects the most recent
91                        // hardware value. For registers with no hardware access, this is simply the
92                        // the value programmed by software (or in the case R1C, W1C etc) the value after
93                        // the operation. For registers with hardware access, this reflects a potentially
94                        // delayed version of the real value, as the software facing updates lag real
95                        // time updates.
96                        //
97                        // To resolve software and hardware conflicts, the process is as follows:
98                        // When software issues a write, this module asserts "busy".  While busy,
99                        // src_q does not take on destination value updates.  Since the
100                       // logic has committed to updating based on software command, there is an irreversible
101                       // window from which hardware writes are ignored.  Once the busy window completes,
102                       // the cdc portion then begins sampling once more.
103                       //
104                       // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105                       // software is always prioritized.  The main difference is the conflict resolution window
106                       // is now larger instead of just one destination clock cycle.
107                     
108                       logic busy;
109        1/1            assign busy = src_busy_q & !src_ack;
           Tests:       T1 T2 T3 
110                     
111                       // This is the current destination value
112                       logic [DataWidth-1:0] dst_qs;
113                       logic src_update;
114                       always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115        1/1              if (!rst_src_ni) begin
           Tests:       T4 T5 T6 
116        1/1                src_q <= ResetVal;
           Tests:       T4 T5 T6 
117        1/1                txn_bits_q <= '0;
           Tests:       T4 T5 T6 
118        1/1              end else if (src_req) begin
           Tests:       T4 T5 T6 
119                           // See assertion below
120                           // At the beginning of a software initiated transaction, the following
121                           // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122                           // change for the duration of the synchronization operation.
123        1/1                src_q <= src_wd_i & BitMask;
           Tests:       T1 T2 T3 
124        1/1                txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
           Tests:       T1 T2 T3 
125        1/1              end else if (src_busy_q && src_ack || src_update && !busy) begin
           Tests:       T4 T5 T6 
126                           // sample data whenever a busy transaction finishes OR
127                           // when an update pulse is seen.
128                           // TODO: We should add a cover group to test different sync timings
129                           // between src_ack and src_update. ie. there can be 3 scenarios:
130                           // 1. update one cycle before ack
131                           // 2. ack one cycle before update
132                           // 3. update / ack on the same cycle
133                           // During all 3 cases the read data should be correct
134        1/1                src_q <= dst_qs;
           Tests:       T1 T2 T3 
135        1/1                txn_bits_q <= '0;
           Tests:       T1 T2 T3 
136                         end
                        MISSING_ELSE
137                       end
138                     
139                       // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140                       // (decoded from address) is busy. So this creates a situation in the current design where
141                       // src_req_i and busy can never be high at the same time.
142                       // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143                       // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144                       // condition cannot be met.
145                       // Thus we add an assertion here to ensure the condition is always satisfied.
146                       `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147                     
148                       // reserved bits are not used
149                       logic unused_wd;
150        1/1            assign unused_wd = ^src_wd_i;
           Tests:       T4 T5 T6 
151                     
152                       // src_q is always updated in the clk_src domain.
153                       // when performing an update to the destination domain, it is guaranteed
154                       // to not change by protocol.
155        1/1            assign src_qs_o = src_q;
           Tests:       T1 T2 T3 
156        1/1            assign dst_wd_o = src_q;
           Tests:       T1 T2 T3 
157                     
158                       ////////////////////////////
159                       // CDC handling
160                       ////////////////////////////
161                     
162                       logic dst_req_from_src;
163                       logic dst_req;
164                     
165                     
166                       // the software transaction is pulse synced across the domain.
167                       // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168                       prim_pulse_sync u_src_to_dst_req (
169                         .clk_src_i,
170                         .rst_src_ni,
171                         .clk_dst_i,
172                         .rst_dst_ni,
173                         .src_pulse_i(src_req),
174                         .dst_pulse_o(dst_req_from_src)
175                       );
176                     
177                       prim_reg_cdc_arb #(
178                         .DataWidth(DataWidth),
179                         .ResetVal(ResetVal),
180                         .DstWrReq(DstWrReq)
181                       ) u_arb (
182                         .clk_src_i,
183                         .rst_src_ni,
184                         .clk_dst_i,
185                         .rst_dst_ni,
186                         .src_ack_o(src_ack),
187                         .src_update_o(src_update),
188                         .dst_req_i(dst_req_from_src),
189                         .dst_req_o(dst_req),
190                         .dst_update_i,
191                         .dst_ds_i,
192                         .dst_qs_i,
193                         .dst_qs_o(dst_qs)
194                       );
195                     
196                     
197                       // Each is valid only when destination request pulse is high; this is important in not propagating
198                       // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199                       // reset.
200        1/1            assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
           Tests:       T1 T2 T3 

---

Cond Coverage for Instance : tb.dut.u_reg.u_usb_meas_ctrl_shadowed_cdc

	Total	Covered	Percent
Conditions	12	11	91.67
Logical	12	11	91.67
Non-Logical	0	0
Event	0	0

 LINE       65
 EXPRESSION (src_we_i | src_re_i)
             ----1---   ----2---

-1-	-2-	Status	Tests
0	0	Covered	T4,T5,T6
0	1	Covered	T1,T50,T27
1	0	Covered	T1,T2,T3

 LINE       109
 EXPRESSION (src_busy_q & ((!src_ack)))
             -----1----   ------2-----

-1-	-2-	Status	Tests
0	1	Covered	T4,T5,T6
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

 LINE       125
 EXPRESSION ((src_busy_q && src_ack) || (src_update && ((!busy))))
             -----------1-----------    ------------2------------

-1-	-2-	Status	Tests
0	0	Covered	T4,T5,T6
0	1	Unreachable
1	0	Covered	T1,T2,T3

 LINE       125
 SUB-EXPRESSION (src_busy_q && src_ack)
                 -----1----    ---2---

-1-	-2-	Status	Tests
0	1	Not Covered
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

 LINE       125
 SUB-EXPRESSION (src_update && ((!busy)))
                 -----1----    ----2----

-1-	-2-	Status	Tests
0	1	Covered	T4,T5,T6
1	0	Unreachable
1	1	Unreachable

---

Branch Coverage for Instance : tb.dut.u_reg.u_usb_meas_ctrl_shadowed_cdc

	Line No.	Total	Covered	Percent
Branches		8	8	100.00
IF	71	4	4	100.00
IF	115	4	4	100.00

71             if (!rst_src_ni) begin
               -1-  
72               src_busy_q <= '0;
                 ==>
73             end else if (src_req) begin
                        -2-  
74               src_busy_q <= 1'b1;
                 ==>
75             end else if (src_ack) begin
                        -3-  
76               src_busy_q <= 1'b0;
                 ==>
77             end
               MISSING_ELSE
               ==>

Branches:

-1-	-2-	-3-	Status	Tests
1	-	-	Covered	T4,T5,T6
0	1	-	Covered	T1,T2,T3
0	0	1	Covered	T1,T2,T3
0	0	0	Covered	T4,T5,T6

115            if (!rst_src_ni) begin
               -1-  
116              src_q <= ResetVal;
                 ==>
117              txn_bits_q <= '0;
118            end else if (src_req) begin
                        -2-  
119              // See assertion below
120              // At the beginning of a software initiated transaction, the following
121              // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122              // change for the duration of the synchronization operation.
123              src_q <= src_wd_i & BitMask;
                 ==>
124              txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
125            end else if (src_busy_q && src_ack || src_update && !busy) begin
                        -3-  
126              // sample data whenever a busy transaction finishes OR
127              // when an update pulse is seen.
128              // TODO: We should add a cover group to test different sync timings
129              // between src_ack and src_update. ie. there can be 3 scenarios:
130              // 1. update one cycle before ack
131              // 2. ack one cycle before update
132              // 3. update / ack on the same cycle
133              // During all 3 cases the read data should be correct
134              src_q <= dst_qs;
                 ==>
135              txn_bits_q <= '0;
136            end
               MISSING_ELSE
               ==>

Branches:

-1-	-2-	-3-	Status	Tests
1	-	-	Covered	T4,T5,T6
0	1	-	Covered	T1,T2,T3
0	0	1	Covered	T1,T2,T3
0	0	0	Covered	T4,T5,T6

---

Assert Coverage for Instance : tb.dut.u_reg.u_usb_meas_ctrl_shadowed_cdc

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

---

Assertion Details

Name	Attempts	Real Successes	Failures	Incomplete
BusySrcReqChk_A	39214857	92998	0	0
DstReqKnown_A	44843662	42357384	0	0
SrcAckBusyChk_A	39214857	18723	0	0
SrcBusyKnown_A	39214857	36366002	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	92998	0	0
T1	2920	51	0	0
T2	44895	117	0	0
T3	0	84	0	0
T10	0	105	0	0
T11	0	54	0	0
T19	2130	0	0	0
T20	1318	0	0	0
T27	0	187	0	0
T28	0	179	0	0
T36	0	101	0	0
T44	949	0	0	0
T45	28709	0	0	0
T46	1704	0	0	0
T47	3012	0	0	0
T48	2269	0	0	0
T49	1302	0	0	0
T50	0	216	0	0
T51	0	92	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	44843662	42357384	0	0
T4	1922	1834	0	0
T5	3069	2974	0	0
T6	829	783	0	0
T29	753	631	0	0
T30	1939	1852	0	0
T31	4223	4184	0	0
T32	5997	5882	0	0
T33	970	855	0	0
T34	4380	4279	0	0
T35	3747	3659	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	18723	0	0
T1	2920	17	0	0
T2	44895	36	0	0
T3	0	14	0	0
T10	0	38	0	0
T11	0	8	0	0
T19	2130	0	0	0
T20	1318	0	0	0
T27	0	76	0	0
T28	0	38	0	0
T36	0	14	0	0
T44	949	0	0	0
T45	28709	0	0	0
T46	1704	0	0	0
T47	3012	0	0	0
T48	2269	0	0	0
T49	1302	0	0	0
T50	0	25	0	0
T51	0	28	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	39214857	36366002	0	0
T4	1922	1834	0	0
T5	1598	1549	0	0
T6	1727	1630	0	0
T29	1539	1290	0	0
T30	1004	962	0	0
T31	1495	1481	0	0
T32	1873	1837	0	0
T33	2022	1781	0	0
T34	1095	1070	0	0
T35	1717	1677	0	0