ha_tb2.v

`include "HA.v"
module ha_tb;
reg A,B;
`ifdef T2
reg clk;
`endif
wire Cout,Sum;

HA HA1(A,B,Cout,Sum);

initial 
begin
$dumpfile("ha.vcd");
$dumpvars(0,HA1);
end
`ifdef T1
initial
begin
#10  A=0; B=0;
#10 $display($time, " %b+%b=%b%b",A,B,Cout,Sum);
if (Sum==0 && Cout==0);
else $display("failed");
A=0; B=1; 
#10 $display($time, " %b+%b=%b%b",A,B,Cout,Sum);
if (Sum==1 && Cout==0);
else $display("failed");
A=1; B=0;
#10$display($time, " %b+%b=%b%b",A,B,Cout,Sum);
if (Sum==1 && Cout==0);
else $display("failed");
 A=1; B=1;
#10 $display($time, " %b+%b=%b%b",A,B,Cout,Sum);
if (Sum==0 && Cout==1);
else $display("failed. Expected '10' and got %b%b",Cout,Sum );
#10 $finish;
end

`elsif T2
initial
begin
A=0;
B=0;
clk=0;
forever #10 clk=~clk;
end

initial
begin
    repeat(10)@(posedge clk)
    begin
    A=$random;
    B=$random;   
    end
#200 $finish;
end
initial
begin
    $monitor("%b+%b = %b%b", A,B,Cout,Sum);
end
`else
initial
$display("NO COMPILER DIRECTIVE");

`endif
endmodule