Subversion Repositories xmatchpro

--This library is free software; you can redistribute it and/or

--modify it under the terms of the GNU Lesser General Public

--License as published by the Free Software Foundation; either

--version 2.1 of the License, or (at your option) any later version.

--This library is distributed in the hope that it will be useful,

--but WITHOUT ANY WARRANTY; without even the implied warranty of

--MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

--Lesser General Public License for more details.

--You should have received a copy of the GNU Lesser General Public

--License along with this library; if not, write to the Free Software

--Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

-- e_mail : j.l.nunez-yanez@byacom.co.uk

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

--  ENTITY       = SHIFT_LITERAL  --

--  version      = 2.0            --

--  last update  = 04/08/99       --

--  author       = Jose Nunez     --

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

-- FUNCTION

-- barrel shifter to remove the match location and match type

-- codes from the decoded data, leaving just literal characters.

-- PIN LIST

-- DIN_LIT   = input data

-- CM_LENGTH = length of the match location and match type codes

-- DOUT_LIT  = output shifted data

library ieee,dzx;

use ieee.std_logic_1164.all;

use dzx.attributes.all;

entity SHIFT_LITERAL is

port

(

      DIN_LIT : in bit_vector(34 downto 0) ;

      CM_LENGTH : in bit_vector(3 downto 0) ;

    --  DECOMP : in bit ;

      DOUT_LIT : out bit_vector(31 downto 0)

);

end SHIFT_LITERAL;

architecture BARREL of SHIFT_LITERAL is

begin

BSHIFT : process(DIN_LIT , CM_LENGTH )

begin

-- if (DECOMP = '0') then

        case CM_LENGTH is

            when "0000" => DOUT_LIT <= DIN_LIT(34 downto 3);

            when "0001" => DOUT_LIT <= DIN_LIT(33 downto 2);

            when "0010" => DOUT_LIT <= DIN_LIT(32 downto 1);

            when "0011" => DOUT_LIT <= DIN_LIT(31 downto 0);

            when "0100" => DOUT_LIT <= DIN_LIT(30 downto 0) & '0';

            when "0101" => DOUT_LIT <= DIN_LIT(29 downto 0) & "00";

            when "0110" => DOUT_LIT <= DIN_LIT(28 downto 0) & "000";

            when "0111" => DOUT_LIT <= DIN_LIT(27 downto 0) & "0000";

            when "1000" => DOUT_LIT <= DIN_LIT(26 downto 0) & "00000";

            when "1001" => DOUT_LIT <= DIN_LIT(25 downto 0) & "000000";

            when "1010" => DOUT_LIT <= DIN_LIT(24 downto 0) & "0000000";

            when "1011" => DOUT_LIT <= DIN_LIT(23 downto 0) & "00000000";

            when "1100" => DOUT_LIT <= DIN_LIT(22 downto 0) & "000000000";

            when "1101" => DOUT_LIT <= DIN_LIT(21 downto 0) & "0000000000";

          when others => DOUT_LIT <= x"00000000";

        end case;

-- else

--      DOUT_LIT <= x"00000000";

-- end if;

end process BSHIFT;

end BARREL; -- end of architecture