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       = CAM_WORD    --

--  version      = 1.0         --

--  last update  = 29/04/98    --

--  author       = Jose Nunez  --

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

-- FUNCTION

-- 32 bit word element of the CAM array.

--  PIN LIST

--  SEARCH    = input search data word

--  PREVIOUS  = data word from the previous location in the array

--  MOVE      = movement control

--  CLEAR     = asynchronous clear of the data latch (active LOW)

--  CLK       = master clock

--  DOUT      = output of the data latch

--  MATCH     = indicates a match between search bytes and data bytes (active LOW)

library ieee;

use ieee.std_logic_1164.all;

entity CAM_WORD_ZERO is

port

(

        SEARCH : in bit_vector(31 downto 0);

        PREVIOUS : in bit_vector(31 downto 0);

        MOVE : in bit;

        CLEAR : in bit ;

        RESET : in bit;

        CLK : in bit ;

        DOUT : out bit_vector(31 downto 0);

        MATCH : out bit_vector(3 downto 0)

);

end CAM_WORD_ZERO;

architecture WORD1 of CAM_WORD_ZERO is

component CAM_BYTE

port

(

        SEARCH : in bit_vector(7 downto 0);

        PREVIOUS : in bit_vector(7 downto 0);

        MOVE : in bit;

        CLEAR : in bit ;

    RESET : in bit;

        CLK : in bit ;

        DOUT : out bit_vector(7 downto 0);

        MATCH : out bit

);

end component;

begin

BYTE1 : CAM_BYTE port map ( SEARCH => SEARCH(7 downto 0),

                                PREVIOUS => PREVIOUS(7 downto 0),

                              MOVE => MOVE,

                              CLEAR => CLEAR,

                                          RESET => RESET,

                                CLK => CLK,

                                DOUT => DOUT(7 downto 0),

                                MATCH => MATCH(0));

BYTE2 : CAM_BYTE port map ( SEARCH => SEARCH(15 downto 8),

                                PREVIOUS => PREVIOUS(15 downto 8),

                                MOVE => MOVE,

                                CLEAR => CLEAR,

                                        RESET => RESET,

                                CLK => CLK,

                                DOUT => DOUT(15 downto 8),

                                MATCH => MATCH(1));

BYTE3 : CAM_BYTE port map ( SEARCH => SEARCH(23 downto 16),

                                PREVIOUS => PREVIOUS(23 downto 16),

                                MOVE => MOVE,

                                CLEAR => CLEAR,

                                        RESET => RESET,

                                CLK => CLK,

                                DOUT => DOUT(23 downto 16),

                                MATCH => MATCH(2));

BYTE4 : CAM_BYTE port map ( SEARCH => SEARCH(31 downto 24),

                                PREVIOUS => PREVIOUS(31 downto 24),

                                MOVE => MOVE,

                                CLEAR => CLEAR,

                                        RESET=> RESET,

                                CLK => CLK,

                                DOUT => DOUT(31 downto 24),

                                MATCH => MATCH(3));

-- No logic for validate the word. All the words valid because the dictionary does not grow

end WORD1;