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-- This file is part of the project  avs_aes

-- see: http://opencores.org/project,avs_aes

--

-- description: Mux2, 2-Port-N-Bit Bit Mulitplexer

--

-------------------------------------------------------------------------------

--

-- Author(s):

--         Thomas Ruschival -- ruschi@opencores.org (www.ruschival.de)

--

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-- Copyright (c) 2009, Authors and opencores.org

-- All rights reserved.

--

-- Redistribution and use in source and binary forms, with or without modification,

-- are permitted provided that the following conditions are met:

--    * Redistributions of source code must retain the above copyright notice,

--    this list of conditions and the following disclaimer.

--    * Redistributions in binary form must reproduce the above copyright notice,

--    this list of conditions and the following disclaimer in the documentation

--    and/or other materials provided with the distribution.

--    * Neither the name of the organization nor the names of its contributors

--    may be used to endorse or promote products derived from this software without

--    specific prior written permission.

-- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

-- AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

-- IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

-- ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE

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-- OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

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-- THE POSSIBILITY OF SUCH DAMAGE

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-- version management:

-- $Author::                                         $

-- $Date::                                           $

-- $Revision::                                       $

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library ieee;

use ieee.std_logic_1164.all;

entity mux2 is

        generic (

                IOwidth : POSITIVE := 32                        -- width of I/O ports

                );

        port (

                inport_a : in  STD_LOGIC_VECTOR (IOwidth-1 downto 0);  -- port 1

                inport_b : in  STD_LOGIC_VECTOR (IOwidth-1 downto 0);  -- port 2

                selector : in  STD_LOGIC;               -- switch to select ports

                outport  : out STD_LOGIC_VECTOR (IOwidth-1 downto 0)   -- output

                );

end mux2;

architecture arch1 of mux2 is

begin  -- arch1

        -- purpose: switch the ports

        -- type   : combinational

        -- inputs : selector,inport_a,inport_b

        -- outputs: outport

        muxing : process (inport_a, inport_b, selector)

        begin  -- PROCESS selector

                -- default behaviour to avoid latch

                outport <= inport_a;

                case selector is

                        when '0' =>

                                outport <= inport_a;

                        when '1' =>

                                outport <= inport_b;

                        when others =>

                                --pragma synthesis_off

                                report "!! selector in arch1 of mux2 has strange value !!" severity warning;

                                --pragma synthesis_on

                end case;

        end process muxing;

end arch1;