干货 | STM32单片机按键消抖和FPGA按键消抖大全

if(GPIO_ReadInputDataBit(GPIOA, GPIO_Pin_14)==1)  {  delay_ms(20);//延时20ms再去检测按键值 if(GPIO_ReadInputDataBit(GPIOA, GPIO_Pin_14)==0) // 相当于下降沿{KEY1 = 1; //表示KEY1被按下}}

typedef struct _Key_t  {  u32 last_time;  enum  {  May_Press,  Release,  }private_state;  enum  {  No_Press,  Short_Press,  Long_Press,  }state; }Key_t;
#define Is_ShortPress_Threshold 1500

if(key_state.private_state==Release) {  if(KEY==0)  {  key_state.private_state=May_Press;  key_state.last_time=course_ms();  } } else if(key_state.private_state==May_Press) {  if(KEY==1)  {  if((course_ms()-key_state.last_time>10)&&(course_ms()-key_state.last_time {  key_state.state=Short_Press;  key_state.private_state=Release;  }  else if(course_ms()-key_state.last_time>Is_ShortPress_Threshold)  {  key_state.state=Long_Press;  key_state.private_state=Release;  }  else  key_state.private_state=Release;  } }

module debounce(    input wire clk, nrst,    input wire key_in,    output reg key_out); // 20ms parameter// localparam TIME_20MS = 1_000_000; localparam TIME_20MS = 1_000; // just for test // variable reg [20:0] cnt; reg key_cnt;  // debounce time passed, refresh key state always @(posedge clk or negedge nrst) begin if(nrst == 0) key_out <= 0; else if(cnt == TIME_20MS - 1) key_out <= key_in; end
 // while in debounce state, count, otherwise 0 always @(posedge clk or negedge nrst) begin if(nrst == 0) cnt <= 0; else if(key_cnt) cnt <= cnt + 1'b1; else cnt <= 0;  end
 //  always @(posedge clk or negedge nrst) begin if(nrst == 0) key_cnt <= 0; else if(key_cnt == 0 && key_in != key_out) key_cnt <= 1; else if(cnt == TIME_20MS - 1) key_cnt <= 0; endendmodule

module debounce( input wire clk, nrst, input wire key_in, output reg key_out );// localparam TIME_20MS = 1_000_000; localparam TIME_20MS = 1_000; reg key_cnt; reg [20:0] cnt; always @(posedge clk or negedge nrst) begin if(nrst == 0) key_cnt <= 0; else if(cnt == TIME_20MS - 1) key_cnt <= 0; else if(key_cnt == 0 && key_out != key_in) key_cnt <= 1; end
 always @(posedge clk or negedge nrst) begin if(nrst == 0) cnt <= 0; else if(key_cnt) begin if(key_out == key_in) cnt <= 0; else cnt <= cnt + 1'b1; end else cnt <= 0; end
 always @(posedge clk or negedge nrst) begin if(nrst == 0) key_out <= 0; else if(cnt == TIME_20MS - 1) key_out <= key_in; endendmodule

module debounce( input wire clk, nrst, input wire key_in, output reg key_out );// localparam TIME_20MS = 1_000_000; localparam TIME_20MS = 1_000; // just for test
 reg key_cnt; reg [20:0] cnt; always @(posedge clk or negedge nrst) begin if(nrst == 0) key_cnt <= 0; else if(key_cnt == 0 && key_out != key_in) key_cnt <= 1; else if(cnt == TIME_20MS - 1) key_cnt <= 0; end
 always @(posedge clk or negedge nrst) begin if(nrst == 0) cnt <= 0; else if(key_cnt) cnt <= cnt + 1'b1; else cnt <= 0; end
 always @(posedge clk or negedge nrst) begin if(nrst == 0) key_out <= 0; else if(key_cnt == 0 && key_out != key_in) key_out <= key_in; endendmodule

// 按键消抖测试电路// 时间单位`timescale 1ns/10ps// modulemodule debounce_tb; // time period parameter localparam T = 20; // variable reg clk, nrst; reg key_in; wire key_out; // instantiate debounce uut( .clk (clk ), .nrst (nrst ), .key_in (key_in ), .key_out(key_out) ); // clock initial begin clk = 1; forever #(T/2) clk = ~clk; end
 // reset initial begin nrst = 1; @(negedge clk) nrst = 0; @(negedge clk) nrst = 1; end
 // key_in initial begin // initial value key_in = 0;  // wait reset repeat(3) @(negedge clk);  // no bounce // key down key_in = 1; // last 60ms repeat(3000) @(negedge clk); // key up key_in = 0; // wait 50ms repeat(2500) @(negedge clk); // down 5ms, up 15ms // key down, bounce 5ms repeat(251) @(negedge clk) key_in = ~key_in; // last 60ms repeat(3000) @(negedge clk); // key up, bounce 15ms repeat(751) @(negedge clk) key_in = ~key_in; // wait 50ms repeat(2500) @(negedge clk); // down 19ms, up 19ms // key down, bounce 19ms repeat(951) @(negedge clk) key_in = ~key_in; // last 60ms repeat(3000) @(negedge clk); // key up, bounce 19ms repeat(951) @(negedge clk) key_in = ~key_in; // wait 50ms repeat(2500) @(negedge clk);  // additional, this situation shoud not ever happen // down 25ms, up 25ms // key down, bounce 25ms repeat(1251) @(negedge clk) key_in = ~key_in; // last 60ms repeat(3000) @(negedge clk); // key up, bounce 25ms repeat(1251) @(negedge clk) key_in = ~key_in; // wait 50ms repeat(2500) @(negedge clk); // stop $stop; endendmodule