f_adder.vhd

全加器

LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
ENTITY f_adder IS
	PORT
	(
		ain,bin,cin		: IN	STD_LOGIC;
		cout,sum    	: OUT	STD_LOGIC
	);
END f_adder;
ARCHITECTURE fd1 OF f_adder IS
	COMPONENT h_adder
	PORT
	(
		a,b		: IN	STD_LOGIC;
		co,so	: OUT	STD_LOGIC
	);
	END COMPONENT;
	COMPONENT or2a
	PORT
	(
		a,b		: IN	STD_LOGIC;
		c   	: OUT	STD_LOGIC
	);
	END COMPONENT;
	SIGNAL d,e,f:STD_LOGIC;
BEGIN
	u1:h_adder PORT MAP(a=>ain, b=>bin,co=>d,so=>e);
	u2:h_adder PORT MAP(a=>e,   b=>cin,co=>f,so=>sum);
	u3:or2a    PORT MAP(a=>d,b=>f,c=>cout);
END ;