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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, 2005 by Wilson Snyder.
// SPDX-License-Identifier: CC0-1.0
module t (/*AUTOARG*/
// Inputs
clk
);
input clk;
reg [11:0] in_a;
reg [31:0] sel;
wire [2:0] out_x;
extractor #(4,3) extractor (
// Outputs
.out (out_x),
// Inputs
.in (in_a),
.sel (sel));
integer cyc; initial cyc=1;
always @ (posedge clk) begin
if (cyc!=0) begin
cyc <= cyc + 1;
//$write("%d %x %x %x\n", cyc, in_a, sel, out_x);
if (cyc==1) begin
in_a <= 12'b001_101_111_010;
sel <= 32'd0;
end
if (cyc==2) begin
sel <= 32'd1;
if (out_x != 3'b010) $stop;
end
if (cyc==3) begin
sel <= 32'd2;
if (out_x != 3'b111) $stop;
end
if (cyc==4) begin
sel <= 32'd3;
if (out_x != 3'b101) $stop;
end
if (cyc==9) begin
$write("*-* All Finished *-*\n");
$finish;
end
end
end
endmodule
module extractor (/*AUTOARG*/
// Outputs
out,
// Inputs
in, sel
);
parameter IN_WIDTH=8;
parameter OUT_WIDTH=2;
input [IN_WIDTH*OUT_WIDTH-1:0] in;
output [OUT_WIDTH-1:0] out;
input [31:0] sel;
wire [OUT_WIDTH-1:0] out = selector(in,sel);
function [OUT_WIDTH-1:0] selector;
input [IN_WIDTH*OUT_WIDTH-1:0] inv;
input [31:0] selv;
integer i;
begin
selector = 0;
for (i=0; i<OUT_WIDTH; i=i+1) begin
selector[i] = inv[selv*OUT_WIDTH+i];
end
end
endfunction
endmodule
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