小梅哥课程学习——LED花式玩法（从计数器器到线性序列机）——实验四

//让LED灯按照指定的亮灭模式亮灭，亮灭模式未知，由用户随即指定。
//8个变换状态为一个循环，每个变换状态的时间可根据不同场景选择。
源代码
module counter_led_4(
    clk,
    reset_n,
    Time,
    ctrl,
    led
);
    input clk;
    input reset_n;
    input [31:0] Time;
    input [7:0] ctrl;
    output reg led;
    reg [31:0] counter;
    always@(posedge clk or negedge reset_n)
        if(!reset_n)
            counter<=0;
        else if(counter==Time-1)
            counter<=0;
        else
            counter=counter+1'b1;
    reg [2:0] counter2;
    always@(posedge clk or negedge reset_n)
        if(!reset_n)
            counter2<=0;
        else if(counter==Time-1)
            counter2<=counter2+1'b1;
     
        always@(posedge clk or negedge reset_n)
        if(!reset_n)
            led<=0;
        else case(counter2)
            0:led<=ctrl[0];
            1:led<=ctrl[1];
            2:led<=ctrl[2];
            3:led<=ctrl[3];
            4:led<=ctrl[4];
            5:led<=ctrl[5];
            6:led<=ctrl[6];
            7:led<=ctrl[7];
            default led<=led;
        endcase
endmodule
仿真代码
`timescale 1ns/1ns
module counter_led_4_tb();
    reg clk;
    reg reset_n;
    reg [31:0] Time;
    reg [7:0] ctrl;
    wire led;
    
    counter_led_4 counter_led_4_inst0(
    .clk(clk),
    .reset_n(reset_n),
    .ctrl(ctrl),
    .Time(Time),
    .led(led)
    );
    initial clk=1;
    always #10 clk=!clk;
    
    initial begin
    reset_n=0;
    ctrl=0;
    Time=0;
    
    #200
    reset_n=1;
    #2000
    Time=2500;
    ctrl=8'b1000_0110;
    Time=2499;
    
    #2000000000;
    $stop;
    end

endmodule