iverilog/ivtest/ivltests/land2.v

98 lines
2.3 KiB
Verilog

/*
* land2 - a verilog test for logical and operator && in boolean context
*
*
* Copyright (C) 1999 Stephen G. Tell
* Portions inspired by qmark.v by Steven Wilson (stevew@home.com)
* Modified by SDW to self test.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, 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 software; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307 USA
*/
module land2;
reg Clk;
reg a;
reg b;
reg c;
reg error;
wire q;
wire q_calc;
tand tand_m(q, q_calc, a, b, c);
initial Clk = 0;
always #10 Clk = ~Clk;
always @(posedge Clk)
begin
#1;
if(q != q_calc)
begin
$display("FAILED - expr && using %b%b%b is %b s/b %b",
a, b, c, q,q_calc);
error = 1;
end
end
reg [3:0] bvec;
integer xa;
integer xb;
integer xc;
initial begin
bvec = 4'bzx10 ;
error = 0;
for(xa = 0; xa <= 3; xa = xa + 1)
for(xb = 0; xb <= 3; xb = xb + 1)
for(xc = 0; xc <= 3; xc = xc + 1)
begin
@(posedge Clk)
a = bvec[xa];
b = bvec[xb];
c = bvec[xc];
end // for (var3 = 0; var3 <= 3; var3 = var3 + 1)
if(error == 0 ) $display("PASSED");
$finish;
end
endmodule
module tand(q, q_calc, a, b, c);
output q;
output q_calc;
input a;
input b;
input c;
wire q = ( (a===b) && (b===c) );
reg q_calc;
always @(a or b or c)
begin
if(a === b)
begin
if( b === c)
q_calc = 1'b1;
else
q_calc = 1'b0;
end
else
q_calc = 1'b0;
end
endmodule // foo