systemverilog操作符

Posted 2021-06-17 薛定谔的猫冫

== / != / === / !===

 1 program main ;
 2 reg a_1,a_0,a_x,a_z;
 3 reg b_1,b_0,b_x,b_z;
 4 initial
 5 begin
 6 a_1 = \'b1;a_0 = \'b0;a_x = \'bx;a_z = \'bz;
 7 b_1 = \'b1;b_0 = \'b0;b_x = \'bx;b_z = \'bz;
 8 $display("--------------------------");
 9 $display (" == 0 1 x z ");
10 $display("--------------------------");
11 $display (" 0 %b %b %b %b ",a_0 == b_0,a_0 == b_1,a_0 == b_x,a_0 == b_z);
12 $display (" 1 %b %b %b %b ",a_1 == b_0,a_1 == b_1,a_1 == b_x,a_1 == b_z);
13 $display (" x %b %b %b %b ",a_x == b_0,a_x == b_1,a_x == b_x,a_x == b_z);
14 $display (" z %b %b %b %b ",a_z == b_0,a_z == b_1,a_z == b_x,a_z == b_z);
15 $display("--------------------------");
16 $display("--------------------------");
17 $display (" === 0 1 x z ");
18 $display("--------------------------");
19 $display (" 0 %b %b %b %b ",a_0 === b_0,a_0 === b_1,a_0 === b_x,a_0 === b_z);
20 $display (" 1 %b %b %b %b ",a_1 === b_0,a_1 === b_1,a_1 === b_x,a_1 === b_z);
21 $display (" x %b %b %b %b ",a_x === b_0,a_x === b_1,a_x === b_x,a_x === b_z);
22 $display (" z %b %b %b %b ",a_z === b_0,a_z === b_1,a_z === b_x,a_z === b_z);
23 $display("--------------------------");
24 $display("--------------------------");
25 $display (" =?= 0 1 x z ");
26 $display("--------------------------");
27 $display (" 0 %b %b %b %b ",a_0 =?= b_0,a_0 =?= b_1,a_0 =?= b_x,a_0 =?= b_z);
28 $display (" 1 %b %b %b %b ",a_1 =?= b_0,a_1 =?= b_1,a_1 =?= b_x,a_1 =?= b_z);
29 $display (" x %b %b %b %b ",a_x =?= b_0,a_x =?= b_1,a_x =?= b_x,a_x =?= b_z);
30 $display (" z %b %b %b %b ",a_z =?= b_0,a_z =?= b_1,a_z =?= b_x,a_z =?= b_z);
31 $display("--------------------------");
32 $display("--------------------------");
33 $display (" != 0 1 x z ");
34 $display("--------------------------");
35 $display (" 0 %b %b %b %b ",a_0 != b_0,a_0 != b_1,a_0 != b_x,a_0 != b_z);
36 $display (" 1 %b %b %b %b ",a_1 != b_0,a_1 != b_1,a_1 != b_x,a_1 != b_z);
37 $display (" x %b %b %b %b ",a_x != b_0,a_x != b_1,a_x != b_x,a_x != b_z);
38 $display (" z %b %b %b %b ",a_z != b_0,a_z != b_1,a_z != b_x,a_z != b_z);
39 $display("--------------------------");
40 $display("--------------------------");
41 $display (" !== 0 1 x z ");
42 $display("--------------------------");
43 $display (" 0 %b %b %b %b ",a_0 !== b_0,a_0 !== b_1,a_0 !== b_x,a_0 !== b_z);
44 $display (" 1 %b %b %b %b ",a_1 !== b_0,a_1 !== b_1,a_1 !== b_x,a_1 !== b_z);
45 $display (" x %b %b %b %b ",a_x !== b_0,a_x !== b_1,a_x !== b_x,a_x !== b_z);
46 $display (" z %b %b %b %b ",a_z !== b_0,a_z !== b_1,a_z !== b_x,a_z !== b_z);
47 $display("--------------------------");
48 $display("--------------------------");
49 $display (" !?= 0 1 x z ");
50 $display("--------------------------");
51 $display (" 0 %b %b %b %b ",a_0 !?= b_0,a_0 !?= b_1,a_0 !?= b_x,a_0 !?= b_z);
52 $display (" 1 %b %b %b %b ",a_1 !?= b_0,a_1 !?= b_1,a_1 !?= b_x,a_1 !?= b_z);
53 $display (" x %b %b %b %b ",a_x !?= b_0,a_x !?= b_1,a_x !?= b_x,a_x !?= b_z);
54 $display (" z %b %b %b %b ",a_z !?= b_0,a_z !?= b_1,a_z !?= b_x,a_z !?= b_z);
55 $display("--------------------------");
56 end
57 endprogram

Result:

--------------------------
== 0 1 x z
--------------------------
0 1 0 x x
1 0 1 x x
x x x x x
z x x x x
--------------------------
--------------------------
=== 0 1 x z
--------------------------
0 1 0 0 0
1 0 1 0 0
x 0 0 1 0
z 0 0 0 1
--------------------------
--------------------------
=?= 0 1 x z
--------------------------
0 1 0 1 1
1 0 1 1 1
x 1 1 1 1
z 1 1 1 1
--------------------------
--------------------------
!= 0 1 x z
--------------------------
0 0 1 x x
1 1 0 x x
x x x x x
z x x x x
--------------------------
--------------------------
!== 0 1 x z
--------------------------
0 0 1 1 1
1 1 0 1 1
x 1 1 0 1
z 1 1 1 0
--------------------------
--------------------------
!?= 0 1 x z
--------------------------
0 0 1 0 0
1 1 0 0 0
x 0 0 0 0
z 0 0 0 0
--------------------------