Unified Coverage Report :: Module :: prim_reg_cdc

Module : prim_reg_cdc

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
98.33	100.00	93.30			100.00	100.00

Source File(s) :
/workspaces/repo/scratch/os_regression_2024_08_31/aon_timer-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_wkup_count_hi_cdc	92.86	100.00	71.43			100.00	100.00
tb.dut.u_reg.u_wkup_ctrl_cdc	97.73	100.00	90.91			100.00	100.00
tb.dut.u_reg.u_wkup_thold_hi_cdc	97.73	100.00	90.91			100.00	100.00
tb.dut.u_reg.u_wkup_thold_lo_cdc	97.73	100.00	90.91			100.00	100.00
tb.dut.u_reg.u_wdog_ctrl_cdc	97.73	100.00	90.91			100.00	100.00
tb.dut.u_reg.u_wdog_bark_thold_cdc	97.73	100.00	90.91			100.00	100.00
tb.dut.u_reg.u_wdog_bite_thold_cdc	97.73	100.00	90.91			100.00	100.00
tb.dut.u_reg.u_wkup_count_lo_cdc	98.21	100.00	92.86			100.00	100.00
tb.dut.u_reg.u_wdog_count_cdc	98.21	100.00	92.86			100.00	100.00
tb.dut.u_reg.u_wkup_cause_cdc	98.44	100.00	93.75			100.00	100.00

---

Module Instance : tb.dut.u_reg.u_wkup_count_hi_cdc

Instance :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
92.86	100.00	71.43			100.00	100.00

Instance's subtree :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
84.89	94.74	75.00			89.83	80.00

Parent :

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

Subtrees :

NAME	SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
u_arb	75.16	92.86	71.74			86.05	50.00
u_src_to_dst_req	100.00	100.00	100.00			100.00	100.00

---

Module Instance : tb.dut.u_reg.u_wkup_ctrl_cdc

Instance :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
97.73	100.00	90.91			100.00	100.00

Instance's subtree :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
99.17	100.00	96.67			100.00	100.00

Parent :

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

Subtrees :

NAME	SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
u_arb	100.00	100.00	100.00			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_wkup_thold_hi_cdc

Instance :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
97.73	100.00	90.91			100.00	100.00

Instance's subtree :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
99.17	100.00	96.67			100.00	100.00

Parent :

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

Subtrees :

NAME	SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
u_arb	100.00	100.00	100.00			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_wkup_thold_lo_cdc

Instance :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
97.73	100.00	90.91			100.00	100.00

Instance's subtree :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
99.17	100.00	96.67			100.00	100.00

Parent :

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

Subtrees :

NAME	SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
u_arb	100.00	100.00	100.00			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_wdog_ctrl_cdc

Instance :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
97.73	100.00	90.91			100.00	100.00

Instance's subtree :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
99.17	100.00	96.67			100.00	100.00

Parent :

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

Subtrees :

NAME	SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
u_arb	100.00	100.00	100.00			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_wdog_bark_thold_cdc

Instance :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
97.73	100.00	90.91			100.00	100.00

Instance's subtree :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
99.17	100.00	96.67			100.00	100.00

Parent :

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

Subtrees :

NAME	SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
u_arb	100.00	100.00	100.00			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_wdog_bite_thold_cdc

Instance :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
97.73	100.00	90.91			100.00	100.00

Instance's subtree :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
99.17	100.00	96.67			100.00	100.00

Parent :

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

Subtrees :

NAME	SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
u_arb	100.00	100.00	100.00			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_wkup_count_lo_cdc

Instance :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
98.21	100.00	92.86			100.00	100.00

Instance's subtree :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
98.11	100.00	94.12			98.31	100.00

Parent :

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

Subtrees :

NAME	SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
u_arb	97.79	100.00	93.48			97.67	100.00
u_src_to_dst_req	100.00	100.00	100.00			100.00	100.00

---

Module Instance : tb.dut.u_reg.u_wdog_count_cdc

Instance :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
98.21	100.00	92.86			100.00	100.00

Instance's subtree :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
98.11	100.00	94.12			98.31	100.00

Parent :

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

Subtrees :

NAME	SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
u_arb	97.79	100.00	93.48			97.67	100.00
u_src_to_dst_req	100.00	100.00	100.00			100.00	100.00

---

Module Instance : tb.dut.u_reg.u_wkup_cause_cdc

Instance :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
98.44	100.00	93.75			100.00	100.00

Instance's subtree :

SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
98.15	100.00	94.29			98.31	100.00

Parent :

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

Subtrees :

NAME	SCORE	LINE	COND	TOGGLE	FSM	BRANCH	ASSERT
u_arb	97.79	100.00	93.48			97.67	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:       T1 T2 T3 
72         1/1                src_busy_q <= '0;
           Tests:       T1 T2 T3 
73         1/1              end else if (src_req) begin
           Tests:       T1 T2 T3 
74         1/1                src_busy_q <= 1'b1;
           Tests:       T1 T2 T3 
75         1/1              end else if (src_ack) begin
           Tests:       T1 T2 T3 
76         1/1                src_busy_q <= 1'b0;
           Tests:       T1 T2 T3 
77                          end
                        MISSING_ELSE
78                        end
79                      
80                        // A src_ack should only be sent if there was a src_req.
81                        // src_busy_q asserts whenever there is a src_req.  By association,
82                        // whenever src_ack is seen, then src_busy must be high.
83                        `ASSERT(SrcAckBusyChk_A, src_ack |-> src_busy_q, clk_src_i, !rst_src_ni)
84                      
85         1/1            assign src_busy_o = src_busy_q;
           Tests:       T1 T2 T3 
86                      
87                        // src_q acts as both the write holding register and the software read back
88                        // register.
89                        // When software performs a write, the write data is captured in src_q for
90                        // CDC purposes.  When not performing a write, the src_q reflects the most recent
91                        // hardware value. For registers with no hardware access, this is simply the
92                        // the value programmed by software (or in the case R1C, W1C etc) the value after
93                        // the operation. For registers with hardware access, this reflects a potentially
94                        // delayed version of the real value, as the software facing updates lag real
95                        // time updates.
96                        //
97                        // To resolve software and hardware conflicts, the process is as follows:
98                        // When software issues a write, this module asserts "busy".  While busy,
99                        // src_q does not take on destination value updates.  Since the
100                       // logic has committed to updating based on software command, there is an irreversible
101                       // window from which hardware writes are ignored.  Once the busy window completes,
102                       // the cdc portion then begins sampling once more.
103                       //
104                       // This is consistent with prim_subreg_arb where during software / hardware conflicts,
105                       // software is always prioritized.  The main difference is the conflict resolution window
106                       // is now larger instead of just one destination clock cycle.
107                     
108                       logic busy;
109        1/1            assign busy = src_busy_q & !src_ack;
           Tests:       T1 T2 T3 
110                     
111                       // This is the current destination value
112                       logic [DataWidth-1:0] dst_qs;
113                       logic src_update;
114                       always_ff @(posedge clk_src_i or negedge rst_src_ni) begin
115        1/1              if (!rst_src_ni) begin
           Tests:       T1 T2 T3 
116        1/1                src_q <= ResetVal;
           Tests:       T1 T2 T3 
117        1/1                txn_bits_q <= '0;
           Tests:       T1 T2 T3 
118        1/1              end else if (src_req) begin
           Tests:       T1 T2 T3 
119                           // See assertion below
120                           // At the beginning of a software initiated transaction, the following
121                           // values are captured in the src_q/txn_bits_q flops to ensure they cannot
122                           // change for the duration of the synchronization operation.
123        1/1                src_q <= src_wd_i & BitMask;
           Tests:       T1 T2 T3 
124        1/1                txn_bits_q <= {src_we_i, src_re_i, src_regwen_i};
           Tests:       T1 T2 T3 
125        1/1              end else if (src_busy_q && src_ack || src_update && !busy) begin
           Tests:       T1 T2 T3 
126                           // sample data whenever a busy transaction finishes OR
127                           // when an update pulse is seen.
128                           // TODO: We should add a cover group to test different sync timings
129                           // between src_ack and src_update. ie. there can be 3 scenarios:
130                           // 1. update one cycle before ack
131                           // 2. ack one cycle before update
132                           // 3. update / ack on the same cycle
133                           // During all 3 cases the read data should be correct
134        1/1                src_q <= dst_qs;
           Tests:       T1 T2 T3 
135        1/1                txn_bits_q <= '0;
           Tests:       T1 T2 T3 
136                         end
                        MISSING_ELSE
137                       end
138                     
139                       // The current design (tlul_adapter_reg) does not spit out a request if the destination it chooses
140                       // (decoded from address) is busy. So this creates a situation in the current design where
141                       // src_req_i and busy can never be high at the same time.
142                       // While the code above could be coded directly to be expressed as `src_req & !busy`, which makes
143                       // the intent clearer, it ends up causing coverage holes from the tool's perspective since that
144                       // condition cannot be met.
145                       // Thus we add an assertion here to ensure the condition is always satisfied.
146                       `ASSERT(BusySrcReqChk_A, busy |-> !src_req, clk_src_i, !rst_src_ni)
147                     
148                       // reserved bits are not used
149                       logic unused_wd;
150        1/1            assign unused_wd = ^src_wd_i;
           Tests:       T1 T2 T3 
151                     
152                       // src_q is always updated in the clk_src domain.
153                       // when performing an update to the destination domain, it is guaranteed
154                       // to not change by protocol.
155        1/1            assign src_qs_o = src_q;
           Tests:       T1 T2 T3 
156        1/1            assign dst_wd_o = src_q;
           Tests:       T1 T2 T3 
157                     
158                       ////////////////////////////
159                       // CDC handling
160                       ////////////////////////////
161                     
162                       logic dst_req_from_src;
163                       logic dst_req;
164                     
165                     
166                       // the software transaction is pulse synced across the domain.
167                       // the prim_reg_cdc_arb module handles conflicts with ongoing hardware updates.
168                       prim_pulse_sync u_src_to_dst_req (
169                         .clk_src_i,
170                         .rst_src_ni,
171                         .clk_dst_i,
172                         .rst_dst_ni,
173                         .src_pulse_i(src_req),
174                         .dst_pulse_o(dst_req_from_src)
175                       );
176                     
177                       prim_reg_cdc_arb #(
178                         .DataWidth(DataWidth),
179                         .ResetVal(ResetVal),
180                         .DstWrReq(DstWrReq)
181                       ) u_arb (
182                         .clk_src_i,
183                         .rst_src_ni,
184                         .clk_dst_i,
185                         .rst_dst_ni,
186                         .src_ack_o(src_ack),
187                         .src_update_o(src_update),
188                         .dst_req_i(dst_req_from_src),
189                         .dst_req_o(dst_req),
190                         .dst_update_i,
191                         .dst_ds_i,
192                         .dst_qs_i,
193                         .dst_qs_o(dst_qs)
194                       );
195                     
196                     
197                       // Each is valid only when destination request pulse is high; this is important in not propagating
198                       // the internal assertion of 'dst_req' by the 'prim_pulse_sync' channel when just one domain is
199                       // reset.
200        1/1            assign {dst_we_o, dst_re_o, dst_regwen_o} = txn_bits_q & {TxnWidth{dst_req}};
           Tests:       T1 T2 T3 

---

Cond Coverage for Module : prim_reg_cdc ( parameter DataWidth=13,ResetVal=0,BitMask=8191,DstWrReq=0,TxnWidth=3 + DataWidth=32,ResetVal=0,BitMask=-1,DstWrReq=0,TxnWidth=3 + DataWidth=32,ResetVal=0,BitMask=-1,DstWrReq=1,TxnWidth=3 + DataWidth=2,ResetVal=0,BitMask=3,DstWrReq=0,TxnWidth=3 )
Cond Coverage for Module self-instances :

SCORE	COND
97.73	90.91

tb.dut.u_reg.u_wkup_ctrl_cdc

SCORE	COND
97.73	90.91

tb.dut.u_reg.u_wkup_thold_hi_cdc

SCORE	COND
97.73	90.91

tb.dut.u_reg.u_wkup_thold_lo_cdc

SCORE	COND
97.73	90.91

tb.dut.u_reg.u_wdog_bark_thold_cdc

SCORE	COND
97.73	90.91

tb.dut.u_reg.u_wdog_bite_thold_cdc

SCORE	COND
92.86	71.43

tb.dut.u_reg.u_wkup_count_hi_cdc

SCORE	COND
98.21	92.86

tb.dut.u_reg.u_wkup_count_lo_cdc

SCORE	COND
98.21	92.86

tb.dut.u_reg.u_wdog_count_cdc

SCORE	COND
97.73	90.91

tb.dut.u_reg.u_wdog_ctrl_cdc

	Total	Covered	Percent
Conditions	14	13	92.86
Logical	14	13	92.86
Non-Logical	0	0
Event	0	0

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

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

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

-1-	-2-	Status	Tests
0	1	Covered	T1,T2,T3
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

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

-1-	-2-	Status	Tests
0	0	Covered	T1,T2,T3
0	1	Covered	T1,T2,T3
1	0	Covered	T1,T2,T3

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

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

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

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

---

Cond Coverage for Module : prim_reg_cdc ( parameter DataWidth=1,ResetVal=0,BitMask=1,DstWrReq=1,TxnWidth=3 )
Cond Coverage for Module self-instances :

SCORE	COND
98.44	93.75

tb.dut.u_reg.u_wkup_cause_cdc

	Total	Covered	Percent
Conditions	16	15	93.75
Logical	16	15	93.75
Non-Logical	0	0
Event	0	0

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

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

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

-1-	-2-	Status	Tests
0	1	Covered	T1,T2,T3
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

 LINE       123
 EXPRESSION (src_wd_i & BitMask)
             ----1---   ---2---

-1-	-2-	Status	Tests
0	-	Covered	T1,T2,T3
1	-	Covered	T34,T35,T36

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

-1-	-2-	Status	Tests
0	0	Covered	T1,T2,T3
0	1	Covered	T1,T2,T3
1	0	Covered	T1,T2,T3

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

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

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

-1-	-2-	Status	Tests
0	1	Covered	T1,T2,T3
1	0	Covered	T26,T32,T33
1	1	Covered	T1,T2,T3

---

Branch Coverage for Module : prim_reg_cdc

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

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

Branches:

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

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

Branches:

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

---

Assert Coverage for Module : prim_reg_cdc

	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	2147483647	26788376	0	0
DstReqKnown_A	24173580	23278580	0	0
SrcAckBusyChk_A	2147483647	31443	0	0
SrcBusyKnown_A	2147483647	2147483647	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	2147483647	26788376	0	0
T1	101980	4366	0	0
T2	105890	5955	0	0
T3	437570	28725	0	0
T4	253730	15560	0	0
T5	145740	5632	0	0
T6	63570	3448	0	0
T7	197590	10081	0	0
T8	89600	5139	0	0
T9	134610	8581	0	0
T10	0	29558	0	0
T11	1012070	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	24173580	23278580	0	0
T1	960	280	0	0
T2	950	210	0	0
T3	900	230	0	0
T4	1020	160	0	0
T5	1150	180	0	0
T6	1260	370	0	0
T7	810	230	0	0
T8	840	200	0	0
T9	1210	210	0	0
T11	8420	160	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	2147483647	31443	0	0
T1	101980	14	0	0
T2	105890	15	0	0
T3	437570	18	0	0
T4	253730	18	0	0
T5	145740	14	0	0
T6	63570	18	0	0
T7	197590	14	0	0
T8	89600	15	0	0
T9	134610	18	0	0
T10	0	18	0	0
T11	1012070	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	2147483647	2147483647	0	0
T1	101980	101150	0	0
T2	105890	104970	0	0
T3	437570	437000	0	0
T4	253730	252990	0	0
T5	145740	145060	0	0
T6	63570	62830	0	0
T7	197590	196690	0	0
T8	89600	88830	0	0
T9	134610	133710	0	0
T11	1012070	1003810	0	0

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

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

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

---

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

	Total	Covered	Percent
Conditions	14	10	71.43
Logical	14	10	71.43
Non-Logical	0	0
Event	0	0

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

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

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

-1-	-2-	Status	Tests
0	1	Covered	T1,T2,T3
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

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

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

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

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

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

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

---

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

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

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

Branches:

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

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

Branches:

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

---

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

	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	600234759	3336023	0	0
DstReqKnown_A	2417358	2327858	0	0
SrcAckBusyChk_A	600234759	3998	0	0
SrcBusyKnown_A	600234759	600046457	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	3336023	0	0
T1	10198	658	0	0
T2	10589	682	0	0
T3	43757	5197	0	0
T4	25373	2605	0	0
T5	14574	860	0	0
T6	6357	536	0	0
T7	19759	1334	0	0
T8	8960	656	0	0
T9	13461	1411	0	0
T10	0	5171	0	0
T11	101207	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	2417358	2327858	0	0
T1	96	28	0	0
T2	95	21	0	0
T3	90	23	0	0
T4	102	16	0	0
T5	115	18	0	0
T6	126	37	0	0
T7	81	23	0	0
T8	84	20	0	0
T9	121	21	0	0
T11	842	16	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	3998	0	0
T1	10198	2	0	0
T2	10589	2	0	0
T3	43757	3	0	0
T4	25373	3	0	0
T5	14574	2	0	0
T6	6357	3	0	0
T7	19759	2	0	0
T8	8960	2	0	0
T9	13461	3	0	0
T10	0	3	0	0
T11	101207	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	600046457	0	0
T1	10198	10115	0	0
T2	10589	10497	0	0
T3	43757	43700	0	0
T4	25373	25299	0	0
T5	14574	14506	0	0
T6	6357	6283	0	0
T7	19759	19669	0	0
T8	8960	8883	0	0
T9	13461	13371	0	0
T11	101207	100381	0	0

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

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

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

---

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

	Total	Covered	Percent
Conditions	11	10	90.91
Logical	11	10	90.91
Non-Logical	0	0
Event	0	0

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

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

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

-1-	-2-	Status	Tests
0	1	Covered	T1,T2,T3
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

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

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

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

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

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

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

---

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

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

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

Branches:

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

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

Branches:

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

---

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

	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	600234759	3612092	0	0
DstReqKnown_A	2417358	2327858	0	0
SrcAckBusyChk_A	600234759	4378	0	0
SrcBusyKnown_A	600234759	600046457	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	3612092	0	0
T1	10198	717	0	0
T2	10589	661	0	0
T3	43757	2846	0	0
T4	25373	1439	0	0
T5	14574	856	0	0
T6	6357	382	0	0
T7	19759	1340	0	0
T8	8960	630	0	0
T9	13461	767	0	0
T10	0	2849	0	0
T11	101207	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	2417358	2327858	0	0
T1	96	28	0	0
T2	95	21	0	0
T3	90	23	0	0
T4	102	16	0	0
T5	115	18	0	0
T6	126	37	0	0
T7	81	23	0	0
T8	84	20	0	0
T9	121	21	0	0
T11	842	16	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	4378	0	0
T1	10198	2	0	0
T2	10589	2	0	0
T3	43757	2	0	0
T4	25373	2	0	0
T5	14574	2	0	0
T6	6357	2	0	0
T7	19759	2	0	0
T8	8960	2	0	0
T9	13461	2	0	0
T10	0	2	0	0
T11	101207	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	600046457	0	0
T1	10198	10115	0	0
T2	10589	10497	0	0
T3	43757	43700	0	0
T4	25373	25299	0	0
T5	14574	14506	0	0
T6	6357	6283	0	0
T7	19759	19669	0	0
T8	8960	8883	0	0
T9	13461	13371	0	0
T11	101207	100381	0	0

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

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

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

---

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

	Total	Covered	Percent
Conditions	11	10	90.91
Logical	11	10	90.91
Non-Logical	0	0
Event	0	0

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

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

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

-1-	-2-	Status	Tests
0	1	Covered	T1,T2,T3
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

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

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

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

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

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

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

---

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

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

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

Branches:

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

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

Branches:

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

---

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

	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	600234759	2038751	0	0
DstReqKnown_A	2417358	2327858	0	0
SrcAckBusyChk_A	600234759	2436	0	0
SrcBusyKnown_A	600234759	600046457	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	2038751	0	0
T1	10198	251	0	0
T2	10589	393	0	0
T3	43757	1385	0	0
T4	25373	689	0	0
T5	14574	365	0	0
T6	6357	161	0	0
T7	19759	658	0	0
T8	8960	362	0	0
T9	13461	431	0	0
T10	0	1375	0	0
T11	101207	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	2417358	2327858	0	0
T1	96	28	0	0
T2	95	21	0	0
T3	90	23	0	0
T4	102	16	0	0
T5	115	18	0	0
T6	126	37	0	0
T7	81	23	0	0
T8	84	20	0	0
T9	121	21	0	0
T11	842	16	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	2436	0	0
T1	10198	1	0	0
T2	10589	1	0	0
T3	43757	1	0	0
T4	25373	1	0	0
T5	14574	1	0	0
T6	6357	1	0	0
T7	19759	1	0	0
T8	8960	1	0	0
T9	13461	1	0	0
T10	0	1	0	0
T11	101207	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	600046457	0	0
T1	10198	10115	0	0
T2	10589	10497	0	0
T3	43757	43700	0	0
T4	25373	25299	0	0
T5	14574	14506	0	0
T6	6357	6283	0	0
T7	19759	19669	0	0
T8	8960	8883	0	0
T9	13461	13371	0	0
T11	101207	100381	0	0

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

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

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

---

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

	Total	Covered	Percent
Conditions	11	10	90.91
Logical	11	10	90.91
Non-Logical	0	0
Event	0	0

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

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

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

-1-	-2-	Status	Tests
0	1	Covered	T1,T2,T3
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

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

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

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

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

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

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

---

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

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

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

Branches:

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

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

Branches:

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

---

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

	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	600234759	2057792	0	0
DstReqKnown_A	2417358	2327858	0	0
SrcAckBusyChk_A	600234759	2474	0	0
SrcBusyKnown_A	600234759	600046457	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	2057792	0	0
T1	10198	262	0	0
T2	10589	396	0	0
T3	43757	1396	0	0
T4	25373	695	0	0
T5	14574	367	0	0
T6	6357	169	0	0
T7	19759	675	0	0
T8	8960	365	0	0
T9	13461	433	0	0
T10	0	1388	0	0
T11	101207	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	2417358	2327858	0	0
T1	96	28	0	0
T2	95	21	0	0
T3	90	23	0	0
T4	102	16	0	0
T5	115	18	0	0
T6	126	37	0	0
T7	81	23	0	0
T8	84	20	0	0
T9	121	21	0	0
T11	842	16	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	2474	0	0
T1	10198	1	0	0
T2	10589	1	0	0
T3	43757	1	0	0
T4	25373	1	0	0
T5	14574	1	0	0
T6	6357	1	0	0
T7	19759	1	0	0
T8	8960	1	0	0
T9	13461	1	0	0
T10	0	1	0	0
T11	101207	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	600046457	0	0
T1	10198	10115	0	0
T2	10589	10497	0	0
T3	43757	43700	0	0
T4	25373	25299	0	0
T5	14574	14506	0	0
T6	6357	6283	0	0
T7	19759	19669	0	0
T8	8960	8883	0	0
T9	13461	13371	0	0
T11	101207	100381	0	0

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

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

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

---

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

	Total	Covered	Percent
Conditions	11	10	90.91
Logical	11	10	90.91
Non-Logical	0	0
Event	0	0

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

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

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

-1-	-2-	Status	Tests
0	1	Covered	T1,T2,T3
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

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

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

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

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

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

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

---

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

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

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

Branches:

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

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

Branches:

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

---

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

	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	600234759	2887569	0	0
DstReqKnown_A	2417358	2327858	0	0
SrcAckBusyChk_A	600234759	3391	0	0
SrcBusyKnown_A	600234759	600046457	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	2887569	0	0
T1	10198	294	0	0
T2	10589	646	0	0
T3	43757	2856	0	0
T4	25373	1441	0	0
T5	14574	371	0	0
T6	6357	389	0	0
T7	19759	702	0	0
T8	8960	713	0	0
T9	13461	767	0	0
T10	0	2856	0	0
T11	101207	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	2417358	2327858	0	0
T1	96	28	0	0
T2	95	21	0	0
T3	90	23	0	0
T4	102	16	0	0
T5	115	18	0	0
T6	126	37	0	0
T7	81	23	0	0
T8	84	20	0	0
T9	121	21	0	0
T11	842	16	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	3391	0	0
T1	10198	1	0	0
T2	10589	2	0	0
T3	43757	2	0	0
T4	25373	2	0	0
T5	14574	1	0	0
T6	6357	2	0	0
T7	19759	1	0	0
T8	8960	2	0	0
T9	13461	2	0	0
T10	0	2	0	0
T11	101207	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	600046457	0	0
T1	10198	10115	0	0
T2	10589	10497	0	0
T3	43757	43700	0	0
T4	25373	25299	0	0
T5	14574	14506	0	0
T6	6357	6283	0	0
T7	19759	19669	0	0
T8	8960	8883	0	0
T9	13461	13371	0	0
T11	101207	100381	0	0

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

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

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

---

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

	Total	Covered	Percent
Conditions	11	10	90.91
Logical	11	10	90.91
Non-Logical	0	0
Event	0	0

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

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

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

-1-	-2-	Status	Tests
0	1	Covered	T1,T2,T3
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

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

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

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

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

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

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

---

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

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

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

Branches:

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

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

Branches:

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

---

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

	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	600234759	2023278	0	0
DstReqKnown_A	2417358	2327858	0	0
SrcAckBusyChk_A	600234759	2432	0	0
SrcBusyKnown_A	600234759	600046457	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	2023278	0	0
T1	10198	247	0	0
T2	10589	383	0	0
T3	43757	1380	0	0
T4	25373	671	0	0
T5	14574	363	0	0
T6	6357	153	0	0
T7	19759	649	0	0
T8	8960	354	0	0
T9	13461	429	0	0
T10	0	1368	0	0
T11	101207	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	2417358	2327858	0	0
T1	96	28	0	0
T2	95	21	0	0
T3	90	23	0	0
T4	102	16	0	0
T5	115	18	0	0
T6	126	37	0	0
T7	81	23	0	0
T8	84	20	0	0
T9	121	21	0	0
T11	842	16	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	2432	0	0
T1	10198	1	0	0
T2	10589	1	0	0
T3	43757	1	0	0
T4	25373	1	0	0
T5	14574	1	0	0
T6	6357	1	0	0
T7	19759	1	0	0
T8	8960	1	0	0
T9	13461	1	0	0
T10	0	1	0	0
T11	101207	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	600046457	0	0
T1	10198	10115	0	0
T2	10589	10497	0	0
T3	43757	43700	0	0
T4	25373	25299	0	0
T5	14574	14506	0	0
T6	6357	6283	0	0
T7	19759	19669	0	0
T8	8960	8883	0	0
T9	13461	13371	0	0
T11	101207	100381	0	0

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

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

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

---

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

	Total	Covered	Percent
Conditions	11	10	90.91
Logical	11	10	90.91
Non-Logical	0	0
Event	0	0

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

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

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

-1-	-2-	Status	Tests
0	1	Covered	T1,T2,T3
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

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

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

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

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

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

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

---

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

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

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

Branches:

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

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

Branches:

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

---

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

	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	600234759	2065585	0	0
DstReqKnown_A	2417358	2327858	0	0
SrcAckBusyChk_A	600234759	2472	0	0
SrcBusyKnown_A	600234759	600046457	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	2065585	0	0
T1	10198	226	0	0
T2	10589	376	0	0
T3	43757	1364	0	0
T4	25373	651	0	0
T5	14574	361	0	0
T6	6357	193	0	0
T7	19759	644	0	0
T8	8960	348	0	0
T9	13461	427	0	0
T10	0	1355	0	0
T11	101207	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	2417358	2327858	0	0
T1	96	28	0	0
T2	95	21	0	0
T3	90	23	0	0
T4	102	16	0	0
T5	115	18	0	0
T6	126	37	0	0
T7	81	23	0	0
T8	84	20	0	0
T9	121	21	0	0
T11	842	16	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	2472	0	0
T1	10198	1	0	0
T2	10589	1	0	0
T3	43757	1	0	0
T4	25373	1	0	0
T5	14574	1	0	0
T6	6357	1	0	0
T7	19759	1	0	0
T8	8960	1	0	0
T9	13461	1	0	0
T10	0	1	0	0
T11	101207	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	600046457	0	0
T1	10198	10115	0	0
T2	10589	10497	0	0
T3	43757	43700	0	0
T4	25373	25299	0	0
T5	14574	14506	0	0
T6	6357	6283	0	0
T7	19759	19669	0	0
T8	8960	8883	0	0
T9	13461	13371	0	0
T11	101207	100381	0	0

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

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

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

---

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

	Total	Covered	Percent
Conditions	14	13	92.86
Logical	14	13	92.86
Non-Logical	0	0
Event	0	0

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

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

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

-1-	-2-	Status	Tests
0	1	Covered	T1,T2,T3
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

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

-1-	-2-	Status	Tests
0	0	Covered	T1,T2,T3
0	1	Covered	T1,T2,T3
1	0	Covered	T1,T2,T3

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

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

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

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

---

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

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

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

Branches:

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

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

Branches:

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

---

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

	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	600234759	3706290	0	0
DstReqKnown_A	2417358	2327858	0	0
SrcAckBusyChk_A	600234759	3996	0	0
SrcBusyKnown_A	600234759	600046457	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	3706290	0	0
T1	10198	784	0	0
T2	10589	1027	0	0
T3	43757	5707	0	0
T4	25373	3364	0	0
T5	14574	863	0	0
T6	6357	760	0	0
T7	19759	2077	0	0
T8	8960	685	0	0
T9	13461	1747	0	0
T10	0	6644	0	0
T11	101207	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	2417358	2327858	0	0
T1	96	28	0	0
T2	95	21	0	0
T3	90	23	0	0
T4	102	16	0	0
T5	115	18	0	0
T6	126	37	0	0
T7	81	23	0	0
T8	84	20	0	0
T9	121	21	0	0
T11	842	16	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	3996	0	0
T1	10198	2	0	0
T2	10589	2	0	0
T3	43757	3	0	0
T4	25373	3	0	0
T5	14574	2	0	0
T6	6357	3	0	0
T7	19759	2	0	0
T8	8960	2	0	0
T9	13461	3	0	0
T10	0	3	0	0
T11	101207	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	600046457	0	0
T1	10198	10115	0	0
T2	10589	10497	0	0
T3	43757	43700	0	0
T4	25373	25299	0	0
T5	14574	14506	0	0
T6	6357	6283	0	0
T7	19759	19669	0	0
T8	8960	8883	0	0
T9	13461	13371	0	0
T11	101207	100381	0	0

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

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

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

---

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

	Total	Covered	Percent
Conditions	14	13	92.86
Logical	14	13	92.86
Non-Logical	0	0
Event	0	0

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

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

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

-1-	-2-	Status	Tests
0	1	Covered	T1,T2,T3
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

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

-1-	-2-	Status	Tests
0	0	Covered	T1,T2,T3
0	1	Covered	T2,T8,T13
1	0	Covered	T1,T2,T3

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

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

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

-1-	-2-	Status	Tests
0	1	Covered	T1,T2,T3
1	0	Covered	T2,T4,T9
1	1	Covered	T2,T8,T13

---

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

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

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

Branches:

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

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

Branches:

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

---

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

	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	600234759	3455683	0	0
DstReqKnown_A	2417358	2327858	0	0
SrcAckBusyChk_A	600234759	4018	0	0
SrcBusyKnown_A	600234759	600046457	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	3455683	0	0
T1	10198	641	0	0
T2	10589	996	0	0
T3	43757	5177	0	0
T4	25373	3297	0	0
T5	14574	856	0	0
T6	6357	519	0	0
T7	19759	1317	0	0
T8	8960	632	0	0
T9	13461	1735	0	0
T10	0	5139	0	0
T11	101207	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	2417358	2327858	0	0
T1	96	28	0	0
T2	95	21	0	0
T3	90	23	0	0
T4	102	16	0	0
T5	115	18	0	0
T6	126	37	0	0
T7	81	23	0	0
T8	84	20	0	0
T9	121	21	0	0
T11	842	16	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	4018	0	0
T1	10198	2	0	0
T2	10589	2	0	0
T3	43757	3	0	0
T4	25373	3	0	0
T5	14574	2	0	0
T6	6357	3	0	0
T7	19759	2	0	0
T8	8960	2	0	0
T9	13461	3	0	0
T10	0	3	0	0
T11	101207	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	600046457	0	0
T1	10198	10115	0	0
T2	10589	10497	0	0
T3	43757	43700	0	0
T4	25373	25299	0	0
T5	14574	14506	0	0
T6	6357	6283	0	0
T7	19759	19669	0	0
T8	8960	8883	0	0
T9	13461	13371	0	0
T11	101207	100381	0	0

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

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

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

---

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

	Total	Covered	Percent
Conditions	16	15	93.75
Logical	16	15	93.75
Non-Logical	0	0
Event	0	0

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

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

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

-1-	-2-	Status	Tests
0	1	Covered	T1,T2,T3
1	0	Covered	T1,T2,T3
1	1	Covered	T1,T2,T3

 LINE       123
 EXPRESSION (src_wd_i & BitMask)
             ----1---   ---2---

-1-	-2-	Status	Tests
0	-	Covered	T1,T2,T3
1	-	Covered	T34,T35,T36

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

-1-	-2-	Status	Tests
0	0	Covered	T1,T2,T3
0	1	Covered	T1,T2,T3
1	0	Covered	T1,T2,T3

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

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

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

-1-	-2-	Status	Tests
0	1	Covered	T1,T2,T3
1	0	Covered	T26,T32,T33
1	1	Covered	T1,T2,T3

---

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

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

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

Branches:

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

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

Branches:

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

---

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

	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	600234759	1605313	0	0
DstReqKnown_A	2417358	2327858	0	0
SrcAckBusyChk_A	600234759	1848	0	0
SrcBusyKnown_A	600234759	600046457	0	0

BusySrcReqChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	1605313	0	0
T1	10198	286	0	0
T2	10589	395	0	0
T3	43757	1417	0	0
T4	25373	708	0	0
T5	14574	370	0	0
T6	6357	186	0	0
T7	19759	685	0	0
T8	8960	394	0	0
T9	13461	434	0	0
T10	0	1413	0	0
T11	101207	0	0	0

DstReqKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	2417358	2327858	0	0
T1	96	28	0	0
T2	95	21	0	0
T3	90	23	0	0
T4	102	16	0	0
T5	115	18	0	0
T6	126	37	0	0
T7	81	23	0	0
T8	84	20	0	0
T9	121	21	0	0
T11	842	16	0	0

SrcAckBusyChk_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	1848	0	0
T1	10198	1	0	0
T2	10589	1	0	0
T3	43757	1	0	0
T4	25373	1	0	0
T5	14574	1	0	0
T6	6357	1	0	0
T7	19759	1	0	0
T8	8960	1	0	0
T9	13461	1	0	0
T10	0	1	0	0
T11	101207	0	0	0

SrcBusyKnown_A

Name	Attempts	Real Successes	Failures	Incomplete
Total	600234759	600046457	0	0
T1	10198	10115	0	0
T2	10589	10497	0	0
T3	43757	43700	0	0
T4	25373	25299	0	0
T5	14574	14506	0	0
T6	6357	6283	0	0
T7	19759	19669	0	0
T8	8960	8883	0	0
T9	13461	13371	0	0
T11	101207	100381	0	0