library IEEE; use IEEE.STD_LOGIC_1164.all; entity oneBitAdder is port( a : in STD_LOGIC; b : in STD_LOGIC; cin : in STD_LOGIC; cout : out STD_LOGIC; s : out STD_LOGIC ); end oneBitAdder; --}} End of automatically maintained section architecture oneBitAdder of oneBitAdder is begin cout <= (a AND b) OR (cin AND (a XOR b)); s <= cin XOR (a XOR b); end oneBitAdder;