iverilog/ivtest/ivltests/xnor_test.v

70 lines
2.0 KiB
Verilog

/*
* Copyright (c) 2000 Guy Hutchison (ghutchis@pacbell.net)
*
* 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
*/
module xnor_test;
reg onebit1, onebit2;
reg [3:0] small1, small2;
reg [15:0] large1, large2, large3, large4;
reg fail;
initial
begin
fail = 0;
// single bit xnor testing
if ((1'b0 ~^ 1'b1) === 1'b1) fail = 1;
if ((1'b1 ^~ 1'b0) === 1'b1) fail = 1;
if ((1'b0 ^~ 1'b0) === 1'b0) fail = 1;
if ((1'b1 ~^ 1'b1) === 1'b0) fail = 1;
// different sized operands (equality)
for (small1=0; small1 < 15; small1=small1+1)
begin
large1 = { 12'b0, small1 };
large2 = small1 ~^ large1;
if (large2 !== {16{1'b1}}) fail = 1;
large2 = large1 ^~ small1;
if (large2 !== {16{1'b1}}) fail = 1;
end
// random test
// assumes +, &, |, and ~ work correctly
for (large1 = 0; large1 < 1000; large1=large1+1)
begin
large2 = large1 + 1511; // prime number
large3 = large1 ^~ large2;
large4 = (large1 & large2) | (~large1 & ~large2);
if (large3 !== large4)
begin
fail = 1;
$display ("Pattern failed: %h != %h", large3, large4);
end
end // for (large1 = 0; large1 < 1000; large1=large1+1)
if (fail)
$display ("FAILED");
else $display ("PASSED");
$finish;
end // initial begin
endmodule // xnor_test