1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
|
// DESCRIPTION: Verilator: Verilog Test module
//
// This file ONLY is placed under the Creative Commons Public Domain, for
// any use, without warranty, 2007 by Wilson Snyder.
// SPDX-License-Identifier: CC0-1.0
module t (/*AUTOARG*/
// Inputs
clk
);
input clk;
reg toggle;
integer cyc; initial cyc=1;
Test test (/*AUTOINST*/
// Inputs
.clk (clk),
.toggle (toggle),
.cyc (cyc[31:0]));
always @ (posedge clk) begin
if (cyc!=0) begin
cyc <= cyc + 1;
toggle <= !cyc[0];
if (cyc==9) begin
end
if (cyc==10) begin
$write("*-* All Finished *-*\n");
$finish;
end
end
end
endmodule
module Test
(
input clk,
input toggle,
input [31:0] cyc
);
// Simple cover
cover property (@(posedge clk) cyc==3);
// With statement, in generate
generate if (1) begin
cover property (@(posedge clk) cyc==4) $display("*COVER: Cyc==4");
end
endgenerate
// Labeled cover
cyc_eq_5:
cover property (@(posedge clk) cyc==5) $display("*COVER: Cyc==5");
// Using default clock
default clocking @(posedge clk); endclocking
cover property (cyc==6) $display("*COVER: Cyc==6");
// Disable statement
// Note () after disable are required
cover property (@(posedge clk) disable iff (toggle) cyc==8)
$display("*COVER: Cyc==8");
cover property (@(posedge clk) disable iff (!toggle) cyc==8)
$stop;
always_ff @ (posedge clk) begin
labeled_icov: cover (cyc==3 || cyc==4);
end
// Immediate cover
labeled_imm0: cover #0 (cyc == 0);
labeled_immf: cover final (cyc == 0);
// Immediate assert
labeled_imas: assert #0 (1);
assert final (1);
//============================================================
// Using a macro and generate
wire reset = (cyc < 2);
`define covclk(eqn) cover property (@(posedge clk) disable iff (reset) (eqn))
genvar i;
generate
for (i=0; i<32; i=i+1)
begin: cycval
CycCover_i: `covclk( cyc[i] );
end
endgenerate
`ifndef verilator // Unsupported
//============================================================
// Using a more complicated property
property C1;
@(posedge clk)
disable iff (!toggle)
cyc==5;
endproperty
cover property (C1) $display("*COVER: Cyc==5");
// Using covergroup
// Note a covergroup is really inheritance of a special system "covergroup" class.
covergroup counter1 @ (posedge cyc);
// Automatic methods: stop(), start(), sample(), set_inst_name()
// Each bin value must be <= 32 bits. Strange.
cyc_value : coverpoint cyc {
}
cyc_bined : coverpoint cyc {
bins zero = {0};
bins low = {1,5};
// Note 5 is also in the bin above. Only the first bin matching is counted.
bins mid = {[5:$]};
// illegal_bins // Has precidence over "first matching bin", creates assertion
// ignore_bins // Not counted, and not part of total
}
toggle : coverpoint (toggle) {
bins off = {0};
bins on = {1};
}
cyc5 : coverpoint (cyc==5) {
bins five = {1};
}
// option.at_least = {number}; // Default 1 - Hits to be considered covered
// option.auto_bin_max = {number}; // Default 64
// option.comment = {string}
// option.goal = {number}; // Default 90%
// option.name = {string}
// option.per_instance = 1; // Default 0 - each instance separately counted (cadence default is 1)
// option.weight = {number}; // Default 1
// CROSS
value_and_toggle: // else default is __<firstlabel>_X_<secondlabel>_<n>
cross cyc_value, toggle;
endgroup
counter1 c1 = new();
`endif
endmodule
|
