aa.vhd

大家一定要看 哦 程序在与多看多练 我找了好久才找到呢

LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
ENTITY aa IS
PORT(d0,d1,sel: IN	BIT;
          q: OUT	BIT);
END aa;
ARCHITECTURE connect OF aa IS
	SIGNAL tmp: BIT;
BEGIN
	cale:  Process (d0,d1,sel)
	VARIABLE tmp1,tmp2,tmp3: BIT;
		BEGIN
		  tmp1:=d0 AND sel;
		  tmp2:=d1 AND (NOT sel);	
		  tmp3:=tmp1 OR tmp2;	
		  tmp<=tmp3;
            q<=tmp;	
			 END PROCESS;
	END connect;