Flash code
module flash (clk,rst,led);
input clk,rst;
output [7:0] led;
reg [2:0] cnt;
wire clk1h;
counter U1(
.clk(clk),
.rst_n(rst),
.clk_1hz(clk1h)
);
decode38 U2(
.sw(cnt),
.led(led)
);
always @(posedge clk or negedge rst)
if(!rst)
cnt <= 1'b0;
else
cnt <= cnt + 1'b1;
endmodule
Counter代码
module counter
(
input clk,
input rst_n,
output reg clk_1hz
);
parameter NUM = 12_000_000;
reg [23:0] cnt;
always @(posedge clk or negedge rst_n)
if(!rst_n) cnt <= 1'b0;
else if(cnt >= (NUM-1)) cnt <= 1'b0;
else cnt <= cnt + 1'b1;
always @(posedge clk or negedge rst_n)
if(!rst_n) clk_1hz <=1'b0;
else if(cnt <= (NUM>>1))
clk_1hz <= 1'b0;
else
clk_1hz <= 1'b1;
endmodule
PWMPulse代码
//********************************************************
// Copyright(c)2016, STEP FPGA
// All rights reserved
// File name : pwmpulse.v
// Module name : pwmpulse
// Author : STEP
// Email : info@stepfpga.com
// Data : 2019/08/01
// Version : V1.0
// Description :
//
// Modification history
// ----------------------------------------------------------------------------
// Version
// Description
//
//********************************************************
//*******************
//DEFINE MODULE PORT
//*******************
module pwmpulse
(
//INPUT
clk ,
rst ,
pwmin,
//OUTPUT
pwmout
);
//*******************
//DEFINE PARAMETER
//*******************
parameter CYCLE = 64;//cycle，产生PWM波形周期的计数器值
//*******************
//DEFINE INPUT
//*******************
input clk,rst; //时钟，复位输入 小脚丫上时钟是12MHz
input [7:0] pwmin; //PWM波形占空比
//*******************
//DEFINE OUTPUT
//*******************
output reg pwmout; //PWM输出
//*********************
//INNER SIGNAL DECLARATION
//*********************
reg [7:0] count;
//产生波形周期的计数器
always@(posedge clk)
if (!rst)
count<=0;
else if(count==CYCLE-1)
count<=0;
else
count<=count+1;
//比较后输出PWM值
always@(*)
if(pwmin>count[7:0])
pwmout<=1;
else
pwmout<=0;
endmodule
PWM代码
module pwm
(
//INPUT
clk ,
rst ,
pwmout
);
input clk,rst;
output pwmout;
wire [7:0] pwmin;
//reg [7:0]pwmin;
pwmpulse u1
(
.clk(clk) ,
.rst(rst) ,
.pwmin(pwmin),
.pwmout(pwmout)
);
assign pwmin = 8'd10;
endmodule