key.vhd

设计一个五路呼叫器,具体设计要求如下: 1．五个按键模拟五个呼叫源 2．当有一个按键按下时

LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
USE IEEE.STD_LOGIC_UNSIGNED.ALL;

ENTITY KEY IS
	PORT( iRES: IN STD_LOGIC;
		  iKEY: IN STD_LOGIC_VECTOR(4 DOWNTO 0);
		  oKEY: OUT STD_LOGIC_VECTOR(4 DOWNTO 0)
		);
END KEY;

ARCHITECTURE FUN OF KEY IS
SIGNAL BKEY: STD_LOGIC_VECTOR(4 DOWNTO 0);
BEGIN
	PROCESS(iRES, iKEY)
	BEGIN
	IF iRES='0'
	THEN BKEY <= "11111";
	ELSE BKEY <= BKEY AND iKEY;
	END IF;
	END PROCESS;
	oKEY <=BKEY;
END FUN;