counter.vhd.bak

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 COUNTER IS
	PORT(iclk : IN STD_LOGIC;
		 iNUM:  IN STD_LOGIC_VECTOR(2 DOWNTO 0);
		 oIS :  OUT STD_LOGIC_VECTOR(4 DOWNTO 0)
		);
END COUNTER;

ARCHITECTURE FUN OF COUNTER IS
BEGIN
	PROCESS(iCLK)
	BEGIN
	IF iCLK'EVENT AND iCLK = '1' THEN
	CASE iNUM IS
	WHEN "001" => oIS <="00001";
	WHEN "010" => oIS <="00010";
	WHEN "011" => oIS <="00100";
	WHEN "100" => oIS <="01000";
	WHEN "101" => oIS <="10000";
	WHEN OTHERS => oIS <="00000";
	END CASE;
	END IF;
	END PROCESS;
END ARCHITECTURE;