74x138 Using when – else statement in data flow model

74x138     Using when – else statement in data flow model

library IEEE;

use IEEE.std_logic_1164.all;

entity dec74x138 is

port ( G1, G2A_L, G2B_L : in  STD_LOGIC;

                    A, B, C : in   STD_LOGIC;

                    Y0_L, Y1_L, Y2_L, Y3_L, Y4_L, Y5_L, Y6_L, Y7_L:  out  STD_LOGIC);

end dec74x138;

architecture arch2 of dec74x138 is

begin

                Y0_L <= ‘0’ when G1 & G2A_L & G2B_L & A & B & C = “100000” else

                       ‘1’;

          Y1_L <= ‘0’ when G1 & G2A_L & G2B_L & A & B & C = “100001” else

                       ‘1’;

          Y2_L <= ‘0’ when G1 & G2A_L & G2B_L & A & B & C = “100010” else

                       ‘1’;

          Y3_L <= ‘0’ when G1 & G2A_L & G2B_L & A & B & C = “100011” else

                       ‘1’;

                Y4_L <= ‘0’ when G1 & G2A_L & G2B_L & A & B & C = “100100” else

                       ‘1’;

          Y5_L <= ‘0’ when G1 & G2A_L & G2B_L & A & B & C = “100101” else

                       ‘1’;

          Y6_L <= ‘0’ when G1 & G2A_L & G2B_L & A & B & C = “100110” else

                       ‘1’;

          Y7_L <= ‘0’ when G1 & G2A_L & G2B_L & A & B & C = “100111” else

                       ‘1’;

end arch2;