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// 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]));
Sub sub1 (.*);
Sub sub2 (.*);
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
//============================================================
// Using a more complicated property
property C1;
@(posedge clk)
disable iff (!toggle)
cyc==5;
endproperty
cover property (C1) $display("*COVER: Cyc==5");
`ifndef verilator // Unsupported
//============================================================
// Using covergroup
// Note a covergroup is really inheritance of a special system "covergroup" class.
covergroup counter1 @ (posedge cyc);
// Automatic methods: stop(), start(), sample(), set_inst_name()
// Each bin value must be <= 32 bits. Strange.
cyc_value : coverpoint cyc {
}
cyc_bined : coverpoint cyc {
bins zero = {0};
bins low = {1,5};
// Note 5 is also in the bin above. Only the first bin matching is counted.
bins mid = {[5:$]};
// 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}; // Default ""
// option.goal = {number}; // Default 90%
// option.name = {string}; // Default ""
// 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
module Sub
(
input clk,
input integer cyc
);
// Simple cover, per-instance
pi_sub:
cover property (@(posedge clk) cyc == 3);
endmodule
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