按键仿真的时分的模型

按键仿真模型

`timescale 1ns/1ns

//仿真模型的建立
module key_model(press,key);

output reg key;
input press;

initial begin
key = 1'b1;
end

always@(posedge press)
key_task;

reg [15:0] myrand; //16位
task key_task;
begin
repeat(50)begin
myrand = {$random}%65536;
#myrand;
key = ~ key;
end
key = 0;//按下按键
#13_000_000;

repeat(50)begin
myrand = {$random}%65536;
#myrand;
key = ~ key;
end
key = 1;//松开按键
#13_000_000;
end
endtask

endmodule