-- dec3to8.vhd 

            LIBRARY ieee; 
            USE ieee.std_logic_1164.all; 
            USE ieee.std_logic_arith.all; 

            ENTITY dec3to8 IS 
            PORT (  a : in std_logic_vector(2 downto 0); 
                         o : out std_logic_vector(7 downto 0)); 
            END dec3to8 ; 

            ARCHITECTURE maxpld OF dec3to8 IS 
            BEGIN  
               PROCESS 
               begin 
                   case a is 
                                when "000" => o <= "00000001"; 
                                when "001" => o <= "00000010"; 
                                when "010" => o <= "00000100"; 
                                when "011" => o <= "00001000";
                                when "100" => o <= "00010000";
                                when "101" => o <= "00100000";
                                when "110" => o <= "01000000";
                                when others => o <= "10000000"; 
                   end case; 
                END  PROCESS; 
             END maxpld;