1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
|
/*
* Exhaustive check of all the subtract results.
*/
module main;
wire [7:0] out;
reg [7:0] A, B;
sub8 dut(.out(out), .A(A), .B(B));
reg error = 0;
integer adx, bdx;
initial begin
A = 0;
B = 0;
for (adx = 0 ; adx < 256 ; adx = adx + 1) begin
A = adx;
for (bdx = 0 ; bdx < 256 ; bdx = bdx + 1) begin
B = bdx;
#1 $write("%b - %b: %b", A, B, out);
if (out !== (A - B)) begin
$display(" ERROR");
error = 1;
end else begin
$display(" OK");
end
end // for (bdx = 0 ; bdx < 256 ; bdx += 1)
end // for (adx = 0 ; adx < 256 ; adx = adx + 1)
if (error == 0)
$display("PASSED");
else
$display("FAILED");
end // initial begin
endmodule // main
|
