iverilog/ivtest/ivltests/cprop.v

62 lines
1.6 KiB
Verilog

/*
* Copyright (c) 2000 Stephen Williams (steve@icarus.com)
*
* This source code is free software; you can redistribute it
* and/or modify it in source code form under the terms of the GNU
* General Public License as published by the Free Software
* Foundation; either version 2 of the License, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
/*
* This test triggers constant propagation through AND gates.
*/
module main;
wire a = 1'b0;
wire b = 1'b1;
wire c = 1'b1;
wire d = 1'bx;
wire out0, out1, out2, out3;
and (out0, a, b); // Should be 0
and (out1, b, c); // Should be 1
and (out2, a, d); // Should be 0 because of a
and (out3, b, d); // Should be x
initial begin
#0 if (out0 !== 1'b0) begin
$display("FAILED -- out0 = %b", out0);
$finish;
end
if (out1 !== 1'b1) begin
$display("FAILED -- out1 = %b", out1);
$finish;
end
if (out2 !== 1'b0) begin
$display("FAILED -- out2 = %b", out2);
$finish;
end
if (out3 !== 1'bx) begin
$display("FAILED -- outx = %b", out3);
$finish;
end
$display("PASSED");
end
endmodule // main