Subversion Repositories potato

-- The Potato Processor - A simple processor for FPGAs

-- (c) Kristian Klomsten Skordal 2014 <kristian.skordal@wafflemail.net>

-- Report bugs and issues on <http://opencores.org/project,potato,bugtracker>

library ieee;

use ieee.std_logic_1164.all;

use ieee.numeric_std.all;

use work.pp_utilities.all;

--! @brief Component for comparing two registers in the ID stage whens branching.

entity pp_comparator is

        port(

                funct3   : in  std_logic_vector(14 downto 12);

                rs1, rs2 : in  std_logic_vector(31 downto 0);

                result   : out std_logic --! Result of the comparison.

        );

end entity pp_comparator;

architecture behaviour of pp_comparator is

begin

        compare: process(funct3, rs1, rs2)

        begin

                case funct3 is

                        when b"000" => -- EQ

                                result <= to_std_logic(rs1 = rs2);

                        when b"001" => -- NE

                                result <= to_std_logic(rs1 /= rs2);

                        when b"100" => -- LT

                                result <= to_std_logic(signed(rs1) < signed(rs2));

                        when b"101" => -- GE

                                result <= to_std_logic(signed(rs1) >= signed(rs2));

                        when b"110" => -- LTU

                                result <= to_std_logic(unsigned(rs1) < unsigned(rs2));

                        when b"111" => -- GEU

                                result <= to_std_logic(unsigned(rs1) >= unsigned(rs2));

                        when others =>

                                result <= '0';

                end case;

        end process compare;

end architecture behaviour;