Subversion Repositories cowgirl

-- ALU

-- 10/24/05

-- Everything here works except for division

library ieee;

use ieee.std_logic_1164.all;

use ieee.std_logic_arith.all;

entity arithmetic is port(

  a:    in signed(15 downto 0);

  b:    in signed(15 downto 0);

  fcn:  in std_logic_vector(2 downto 0);

  o:    out signed(15 downto 0);

  m_o:  out signed(31 downto 0)

  );

end arithmetic;

architecture arith_arch of arithmetic is

  signal temp: signed(31 downto 0);

begin

  arith_logic: process(fcn, a, b)

  begin

    case fcn is

      when "000" =>                     -- add

        o <= a + b;

      when "001" =>                     -- subtract

        o <= a - b;

      when "010" =>                     -- multiply

        m_o <= a * b;

      when "011" =>                     -- divide

        --o <= a / b;

      when "100" =>                     -- 2's complement inverse

        o <= signed((not std_logic_vector(a))) + '1';

      when others =>

        o <= x"0000";

    end case;

  end process arith_logic;

end arith_arch;