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       = PARSING_UNIT            --

--  version      = 1.0                     --

--  last update  = 30/05/00                --

--  author       = Jose Nunez              --

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

-- FUNCTION

-- The parsing unit parses the input data in words using the space as the parser

--  PIN LIST

--  ENABLE = parsing unit active

--  DATA_IN_32  = data to be parse from the buffer

--  MASK = 4 bit indicatin how many bytes of the 32 are valid

--  DATA_OUT_32  = output data to the search register

--  CLEAR    = asynchronous clear

--  CLK      = master clock

library ieee;

use ieee.std_logic_1164.all;

entity PARSING_UNIT is

port

(

        ENABLE: in bit; -- buffer ready

        FINISH : in bit; -- all the data has been processed

        DATA_IN_32 : in bit_vector(31 downto 0);

        CLEAR : in bit ;

        CLK : in bit ;

        MASK : out bit_vector(4 downto 0);

    READ : out bit;

        START_ENGINE : out bit;

        FINISH_PARSING : out bit;

        DATA_OUT_32: out bit_vector(31 downto 0)

);

end PARSING_UNIT;

architecture STRUCTURAL of PARSING_UNIT is

component PARSER_REGISTER

port (

          ENABLE_IN : in bit;

          DATA_IN : in bit_vector(55 downto 0);

          LENGTH_IN : in bit_vector(2 downto 0);

          CLK : in bit;

          CLEAR : in bit;

          RESET : in bit;

          ENABLE_OUT : out bit;

          DATA_OUT : out bit_vector(55 downto 0);

          LENGTH_OUT: out bit_vector(2 downto 0)

         );

end component;

component PARSER

port (

          DATA_IN : in bit_vector(55 downto 0);

          LENGTH_IN : in bit_vector(2 downto 0);

          ENABLE : in bit; -- hold the state when the buffer is empty but still more data in the block

          FINISH : in bit; -- last block is over

          DATA_SEARCH : out bit_vector(31 downto 0);

          DATA_OUT : out bit_vector(55 downto 0);

          MASK : out bit_vector(4 downto 0);

          LENGTH_OUT : out bit_vector(2 downto 0)

         );

end component;

component PARSER_CONCATENATOR

port

        (

        DATA_IN_BUFFER : in bit_vector(31 downto 0);

        ENABLE : in bit;

        READ : in bit;

        DATA_OLD : in bit_vector(55 downto 0);

        LENGTH_OLD : in bit_vector(2 downto 0);

        DATA_NEW : out bit_vector(55 downto 0);

        LENGTH_NEW : out bit_vector(2 downto 0)

        );

end component;

signal DATA_NEW, DATA_REG, DATA_PARSER : bit_vector(55 downto 0);

signal LENGTH_NEW, LENGTH_REG, LENGTH_PARSER: bit_vector(2 downto 0);

signal ENABLE_INT : bit;

signal READ_NOW : bit;

signal READ_INT : bit;

begin

PARSER_REGISTER_1 : PARSER_REGISTER

port map (

          ENABLE_IN => READ_INT,

          DATA_IN =>DATA_NEW,

          LENGTH_IN =>LENGTH_NEW,

          CLK =>CLK,

          CLEAR =>CLEAR,

          RESET =>CLEAR,

          ENABLE_OUT => READ_NOW,

          DATA_OUT =>DATA_REG,

          LENGTH_OUT =>LENGTH_REG

         );

PARSER_1 : PARSER

port map(

          DATA_IN => DATA_PARSER,

          LENGTH_IN => LENGTH_PARSER,

          ENABLE => ENABLE,  -- hold the state when the buffer is empty but still more data in the block

          FINISH => FINISH, -- last block is over

          DATA_SEARCH => DATA_OUT_32,

          DATA_OUT => DATA_NEW,

          MASK => MASK,

          LENGTH_OUT => LENGTH_NEW

         );

PARSER_CONCATENATOR_1 : PARSER_CONCATENATOR

port map

        (

        DATA_IN_BUFFER =>DATA_IN_32,

        ENABLE => ENABLE,

        READ => READ_NOW,

        DATA_OLD => DATA_REG,

        LENGTH_OLD =>LENGTH_REG,

        DATA_NEW =>DATA_PARSER,

        LENGTH_NEW=> LENGTH_PARSER

        );

READ_INT <= not(LENGTH_NEW(2)); -- and ENABLE;

READ <= READ_INT;

START_ENGINE <= '1' when (ENABLE = '1' or (LENGTH_PARSER > "000" and FINISH = '1')) else '0';

FINISH_PARSING <= '1' when (LENGTH_PARSER= "000" and FINISH = '1') else '0';

end STRUCTURAL;