Subversion Repositories cowgirl

-- 10/25/2005

-- Logical Unit

library ieee;

use ieee.std_logic_1164.all;

entity logical is port(

        a:      in std_logic_vector(15 downto 0);

        b:      in std_logic_vector(15 downto 0);

        fcn:    in std_logic_vector(2 downto 0);

        o:      out std_logic_vector(15 downto 0)

);

end logical;

architecture logic_arch of logical is

begin

        logical_logic: process(fcn)

        begin

                case fcn is

                        when "000" =>                   -- not

                                o <= not(a);

                        when "001" =>                   -- and

                                o <= a and b;

                        when "010" =>                   -- or

                                o <= a or b;

                        when "011" =>                   -- xor

                                o <= a xor b;

                        when "100" =>                   -- nand

                                o <= a nand b;

                        when "101" =>                   -- nor

                                o <= a nor b;

                        when others =>

                                o <= x"0000";

                end case;

        end process logical_logic;

end logic_arch;