library IEEE; use IEEE.std_logic_1164.all; entity V2to4dec is port ( G: in STD_LOGIC; A: in STD_LOGIC_VECTOR (1 downto 0); Y: out STD_LOGIC_VECTOR (0 to 3) ); end V2to4dec; architecture V2to4dec_a of V2to4dec is signal Y_s: STD_LOGIC_VECTOR (0 to 3); -- internal signal begin with A select Y_s <= "1000" when "00", "0100" when "01", "0010" when "10", "0001" when "11", "0000" when others; Y <= Y_s when G='1' else "0000"; end V2to4dec_a;