一位二进制全加/减器设计

library ieee; use ieee.std_logic_1164.all; entity addt is port (ain,bin,cin :in std_logic; cout,sum :out std_logic); end entity addt; architecture fd1 of addt 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 architecture fd1;