fredevider.vhd

十字路口交通信号灯试验,用max＋plusII编程。希望对大家有用

LIBRARY IEEE;
USE IEEE.Std_Logic_1164.ALL;
ENTITY FreDevider IS
PORT
  (Clkin:IN Std_Logic;
   Clkout:OUT Std_Logic);
END;
ARCHITECTURE Devider OF FreDevider IS
CONSTANT N:Integer:=499;
signal counter:Integer range 0 to N;
signal Clk:Std_Logic;
BEGIN 
 PROCESS(Clkin)
  begin 
    IF rising_edge(Clkin)THEN
      IF Counter=N then 
         counter<=0;
         Clk<=not clk;
        else
        counter<=counter+1;
      end if;
    end if;
  end process;
 clkout<=clk;
end;