2位元比較器之compare_2_str

module top;
reg A1,A0,B1,B0;
wire A_lt_B,A_gt_B,A_eq_B;
compare_2_str m1(A_lt_B,A_gt_B,A_eq_B,A1,A0,B1,B0);
initial
begin
A1=0;
A0=0;
B1=0;
B0=0;

#2000 $finish;
end
always
#30 A1=~A1;
always
#40 A0=~A0;
always
#50 B1=~B1;
always
#60 B0=~B0;

endmodule

module compare_2_str(A_lt_B,A_gt_B,A_eq_B,A0,A1,B0,B1);
input A0,A1,B0,B1;
output A_lt_B,A_gt_B,A_eq_B;
wire w1,w2,w3,w4,w5,w6,w7;

or (A_lt_B,w1,w2,w3);
nor (A_gt_B,A_lt_B,A_eq_B);
and (A_eq_B,w4,w5);
and (w1,w6,B1);
and (w2,w6,w7,B0);
and (w3,w7,B0,B1);
not (w6,A1);
not (w7,A0);
xnor (w4,A1,B0);
xnor (w5,A0,B0);
endmodule