div5.vhd

时钟分配和分路传输功能的VHDL语言程序

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.STD_LOGIC_ARITH.ALL;
use IEEE.STD_LOGIC_UNSIGNED.ALL;

--  Uncomment the following lines to use the declarations that are
--  provided for instantiating Xilinx primitive components.
--library UNISIM;
--use UNISIM.VComponents.all;

LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
USE IEEE.STD_LOGIC_UNSIGNED.ALL;
ENTITY DIV5 IS
	PORT(
		CLK, CLR: IN	STD_LOGIC;
		Q5 : OUT	STD_LOGIC);
END DIV5;

ARCHITECTURE a OF DIV5 IS
	SIGNAL COUNTA: STD_LOGIC_VECTOR(2 DOWNTO 0);
BEGIN
Q5<= COUNTA(1);
P1:PROCESS (CLK,CLR)
	BEGIN
	IF (CLR='1') THEN
		COUNTA<="000";
	ELSIF FALLING_EDGE(CLK) THEN
		IF(COUNTA<="011") THEN
			COUNTA<= COUNTA+1;
		ELSE 
			COUNTA<="000";
		END IF;
	END IF;
END PROCESS P1;
end a;