LIBRARY ieee ;
USE ieee.std_logic_1164.all ;
ENTITY Lab4 IS
    PORT (  bcd     : IN    STD_LOGIC_VECTOR(3 DOWNTO 0) ;
        leds    : OUT   STD_LOGIC_VECTOR(1 TO 7) ) ;
END Lab4 ;
ARCHITECTURE Behavior OF Lab4 IS
BEGIN
    PROCESS ( bcd )
    BEGIN
        CASE bcd IS                      ------    abcdefg
            WHEN "0000"     => leds     <=        "0000001" ;
            WHEN "0001"     => leds     <=        "1001111" ;
            WHEN "0010"     => leds     <=        "0010010" ;
            WHEN "0011"     => leds     <=        "0000110" ;
            WHEN "0100"     => leds     <=        "1001100" ;
            WHEN "0101"     => leds     <=        "0100100" ;
            WHEN "0110"     => leds     <=        "0100000" ;
            WHEN "0111"     => leds     <=        "0001111" ;
            WHEN "1000"     => leds     <=        "0000000" ;
            WHEN "1001"     => leds     <=        "0001100" ;
                                         ------    abcdefg
            WHEN "1010"     =>-- ten.
                                  leds <=        "0001000" ;

            WHEN "1011"     => -- elleven
                                  leds <=        "1100000" ;

            WHEN "1100"     => -- twelve
                                  leds <=        "0110001" ; -- none.

            WHEN "1101"     => -- thirteen
                                  leds <=        "1000010" ; -- none.

            WHEN "1110"     => -- fourteen.
                                  leds <=        "0110000" ; -- none.

            WHEN "1111"     => -- fifteen.
                                  leds <=        "0111000" ;

            WHEN OTHERS     => -- none.
                                  leds <=        "1111111" ; -- none.
        END CASE ;
    END PROCESS ;
END Behavior ;