按键防抖动模块.txt

这是一个交通灯控制的程序 基本上实现了功能

library ieee;
use ieee.std_logic_1164.all;
entity fangdou is
 port(clk100:in std_logic;
       keyin:in std_logic;
      keyout:out std_logic);
end fangdou;
architecture a of fangdou is
signal tmp1,tmp2:std_logic;
begin
 process(clk100)
  begin
   if(clk100'event and clk100='0') then
    tmp2<=tmp1;
    tmp1<=keyin;
   end if;
  end process;
keyout<=clk100 and tmp1 and (not tmp2);
end a;