1 //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。
2 //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。
3 源代码
4 module counter_led_4(
5 clk,
6 reset_n,
7 Time,
8 ctrl,
9 led
10 );
11 input clk;
12 input reset_n;
13 input [31:0] Time;
14 input [7:0] ctrl;
15 output reg led;
16 reg [31:0] counter;
17 always@(posedge clk or negedge reset_n)
18 if(!reset_n)
19 counter<=0;
20 else if(counter==Time-1)
21 counter<=0;
22 else
23 counter=counter+1'b1;
24 reg [2:0] counter2;
25 always@(posedge clk or negedge reset_n)
26 if(!reset_n)
27 counter2<=0;
28 else if(counter==Time-1)
29 counter2<=counter2+1'b1;
30
31 always@(posedge clk or negedge reset_n)
32 if(!reset_n)
33 led<=0;
34 else case(counter2)
35 0:led<=ctrl[0];
36 1:led<=ctrl[1];
37 2:led<=ctrl[2];
38 3:led<=ctrl[3];
39 4:led<=ctrl[4];
40 5:led<=ctrl[5];
41 6:led<=ctrl[6];
42 7:led<=ctrl[7];
43 default：led<=led;
44 endcase
45 endmodule
46 仿真代码
47 `timescale 1ns/1ns
48 module counter_led_4_tb();
49 reg clk;
50 reg reset_n;
51 reg [31:0] Time;
52 reg [7:0] ctrl;
53 wire led;
54
55 counter_led_4 counter_led_4_inst0(
56 .clk(clk),
57 .reset_n(reset_n),
58 .ctrl(ctrl),
59 .Time(Time),
60 .led(led)
61 );
62 initial clk=1;
63 always #10 clk=!clk;
64
65 initial begin
66 reset_n=0;
67 ctrl=0;
68 Time=0;
69
70 #201;
71 reset_n=1;
72 #2000
73 Time=2500;
74 ctrl=8'b1000_0110;
75 Time=2499;
76
77 #2000000000;
78 $stop;
79 end
80
81 endmodule
82
