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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, 2004 by Wilson Snyder.
// SPDX-License-Identifier: CC0-1.0
module t (/*AUTOARG*/
// Inputs
clk
);
input clk;
integer cyc; initial cyc=1;
reg [31:0] wr_data;
reg wr_en;
wire [31:0] rd_data;
wire [1:0] rd_guards;
wire [1:0] rd_guardsok;
regfile regfile (/*AUTOINST*/
// Outputs
.rd_data (rd_data[31:0]),
.rd_guards (rd_guards[1:0]),
.rd_guardsok (rd_guardsok[1:0]),
// Inputs
.wr_data (wr_data[31:0]),
.wr_en (wr_en),
.clk (clk));
initial wr_en = 0;
always @ (posedge clk) begin
if (cyc!=0) begin
cyc <= cyc + 1;
if (cyc==1) begin
if (!rd_guards[0]) $stop;
if (!rd_guardsok[0]) $stop;
wr_en <= 1'b1;
wr_data <= 32'hfeedf;
end
if (cyc==2) begin
wr_en <= 0;
end
if (cyc==3) begin
wr_en <= 0;
if (rd_data != 32'hfeedf) $stop;
if (rd_guards != 2'b11) $stop;
if (rd_guardsok != 2'b11) $stop;
end
if (cyc==4) begin
$write("*-* All Finished *-*\n");
$finish;
end
end
end
endmodule
module regfile (
input [31:0] wr_data,
input wr_en,
output reg [31:0] rd_data,
output [1:0] rd_guards /*verilator public*/,
output [1:0] rd_guardsok /*verilator public*/,
input clk
);
always @(posedge clk) begin
if (wr_en)
begin
rd_data <= wr_data;
end
end
// this initial statement will induce correct initialize behavior
// initial rd_guards= { 2'b11 };
assign rd_guards= {
rd_data[0],
1'b1
};
assign rd_guardsok[0] = 1'b1;
assign rd_guardsok[1] = rd_data[0];
endmodule // regfile
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