sys_tb.v

verilog hdl经典例程

`timescale 1ns/100ps
module Top;
reg D_out,SEND,ESC,DSC,TAKE,ADD_100,ADD_101;
reg [7:0] data_buf;
wire [7:0] data;
wire clk2;
//wire clk2;
assign data=(ADD_101)?data_buf:8'bz;
assign clk2=DSC&&TAKE;
initial
begin
SEND=0;
ESC=0;
DSC=1;
TAKE=1;
ADD_100=1;
ADD_101=1;
end
initial
begin
data_buf=8'b10000001;
#90 ADD_100=0;
#100 ADD_100=1;
end
always
begin
#50;
SEND=~SEND;
ESC=~ESC;
end
initial
begin
#1500;
SEND=0;
ESC=0;
DSC=1;
TAKE=1;
ADD_100=1;
ADD_101=1;
D_out=0;
#1150 ADD_101=0;
#100 ADD_101=1;
#100 $stop;
end
always
begin
#50;
DSC=~DSC;
TAKE=~TAKE;
end
always @(negedge clk2) D_out=~D_out;
sys sys(.D_in(D_in),.T0(T0),.data(data),.D_out(D_out),.ADD_101(ADD_101),.SEND(SEND),.ESC(ESC),.DSC(DSC),.TAKE(TAKE),.ADD_100(ADD_100));
endmodule