library ieee;
use ieee.std_logic_1164.all;

entity flygplats is

        port(r:in std_logic_vector(3 downto 0);
                 y:out std_logic_vector(2 downto 0));

end flygplats;

architecture beteende of flygplats is
begin

        flyg_d: process (r, y)
        begin

                if r(0) = '1' then y<= "001";
                elsif r(1) = '1' then y<= "010";
                elsif r(2) = '1' then y<= "011";
                elsif r(3) = '1' then y<= "100";
                else y<= "000";

                end if;
        end process flyg_d;
end beteende;