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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, 2003 by Wilson Snyder.
// SPDX-License-Identifier: CC0-1.0
// ======================================================================
module sub
(
input clk,
input fastclk,
input reset_l
);
// Example counter/flop
reg [31:0] count_f;
always_ff @(posedge fastclk) begin
if (!reset_l) begin
/*AUTORESET*/
// Beginning of autoreset for uninitialized flops
count_f <= 32'h0;
// End of automatics
end
else begin
count_f <= count_f + 1;
end
end
// Another example flop
reg [31:0] count_c;
always_ff @(posedge clk) begin
if (!reset_l) begin
/*AUTORESET*/
// Beginning of autoreset for uninitialized flops
count_c <= 32'h0;
// End of automatics
end
else begin
count_c <= count_c + 1;
if (count_c >= 3) begin
$display("[%0t] fastclk is %0d times faster than clk\n", $time, count_f / count_c);
// This write is a magic value the Makefile uses to make sure the
// test completes successfully.
$write("*-* All Finished *-*\n");
$finish;
end
end
end
// An example assertion
always_ff @(posedge clk) begin
AssertionExample : assert (!reset_l || count_c < 100);
end
// And example coverage analysis
cover property (@(posedge clk) count_c == 3);
endmodule
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