分频.txt

来自「设计制作一个用于十字路口的交通灯控制器 有一组绿、黄、红灯用于指挥交通」· 文本 代码 · 共 50 行

library ieee;
use ieee.std_logic_1164.all;
use ieee.std_logic_unsigned.all;
entity fenpin is
 port(clk:in std_logic;
      clk1k,clk100,clk1:out std_logic);
end fenpin;
architecture a of fenpin is
signal count:integer range 0 to 999;
signal count1:integer range 0 to 9;
signal count2:integer range 0 to 99;
signal m,n:std_logic;
begin
p1: process(clk) 
  begin
   if(clk'event and clk='1')then
     if(count=999) then count<=0;
     else count<=count+1;
     end if;
     if(count<500) then m<='1';
     else m<='0';
     end if;
   end if;
  end process;
p2:process(m)
 begin
  if(m'event and m='1') then
    if(count1=9)then count1<=0;
    else count1<=count1+1;
    end if;    
    if(count1<5)then n<='1';
    else n<='0';
    end if;
  end if;
 end process;
p3:process(n) 
 begin
  if(n'event and n='1')then
    if(count2=99)then count2<=0;
    else count2<=count2+1;
    end if;
    if(count2<50)then clk1<='1';
    else clk1<='0';
    end if;
  end if;
end process;
clk1k<=m;
clk100<=n;
end;