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       = REG_FILE             --

--  version      = 1.0                      --

--  last update  = 11/09/00         --

--  author       = Jose Nunez           --

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

-- FUNCTION

-- 16 bit wide treshold register

--  PIN LIST

--  DIN   = 16 bit input data

--  ADDRESS = 2 bit to address 

--  RW = read and write

--  ENABLE = enable the load

--  CLEAR = asynchronous clear of register

--  CLK   = clock

--  DOUT  = 16 bit output of flip-flops

--  C_BS_OUT = compressed block size 

--  U_BS_OUT = uncompressed block size

--  START_C = start the compression engine

--  START_D = start the decompression engine

--  STOP = stop the process

--  THRESHOLD_LEVEL = the threshold level of the buffers

library ieee,dzx;

use ieee.std_logic_1164.all;

use dzx.attributes.all;

entity REG_FILE_D is

port

(

      DIN : in bit_vector(31 downto 0);

          ADDRESS : in bit_vector(1 downto 0);

          CRC_IN : in bit_vector(31 downto 0);

          LOAD_CRC : in bit;

      RW : in bit;

      CLEAR_CR : in bit;

      ENABLE : in bit;

      CLEAR : in bit;

        CLK : in bit;

        DOUT : out std_logic_vector(31 downto 0);

        C_BS_OUT : out bit_vector(31 downto 0);

        U_BS_OUT : out bit_vector(31 downto 0);

        CRC_OUT : out bit_vector(31 downto 0);

        START_D : out bit;

        STOP :out bit;

        THRESHOLD_LEVEL : out bit_vector(7 downto 0)

);

end REG_FILE_D;

architecture LATCH of REG_FILE_D is

component CONTROL_REG

port

(

      DIN : in bit_vector(31 downto 0);

      ENABLE : in bit;

      CLEAR : in bit;

        CLK : in bit;

      DOUT : out bit_vector(31 downto 0)

);

end component;

type TYPE_ARRAY is array(3 downto 0) of bit_vector(31 downto 0);

signal ARRAY_OUT : TYPE_ARRAY;

signal ENABLE_INT : bit_vector(3 downto 0);

signal ENABLE_CODE : bit_vector(3 downto 0);

signal ENABLE_REG_CBS : bit;

signal DIN_REG_CBS: bit_vector(31 downto 0);

signal ENABLE_REG_CR : bit;

signal DIN_REG_CR: bit_vector(31 downto 0);

signal ENABLE_REG_CRC : bit;

signal DIN_REG_CRC: bit_vector(31 downto 0);

begin

ENABLE_CODE <= ADDRESS & RW & ENABLE;

-- RW write =0

-- ENABLE active =0

WRITE : process(ENABLE_CODE)

begin

case ENABLE_CODE is

    when "0000" => ENABLE_INT <= "0001";

    when "0100" => ENABLE_INT <= "0010";

    when "1000" => ENABLE_INT <= "0100";

        when "1100" => ENABLE_INT <= "1000";

    when others => ENABLE_INT <= "0000";

end case;

end process WRITE;

READ : process(ENABLE_CODE, ARRAY_OUT)

begin

case ENABLE_CODE is

    when "0010" => DOUT <= To_X01Z(ARRAY_OUT(0));

    when "0110" => DOUT <= To_X01Z(ARRAY_OUT(1));

    when "1010" => DOUT <= To_X01Z(ARRAY_OUT(2));

        when "1110" => DOUT <= To_X01Z(ARRAY_OUT(3));

    when others => DOUT  <= X"00000000";

end case;

end process READ;

REG_CR : CONTROL_REG

port map ( DIN => DIN_REG_CR,

      ENABLE => ENABLE_REG_CR,

      CLEAR => CLEAR,

      CLK => CLK,

      DOUT => ARRAY_OUT(0));

REG_UBS : CONTROL_REG

port map ( DIN => DIN,

      ENABLE => ENABLE_INT(1),

      CLEAR => CLEAR,

      CLK => CLK,

      DOUT => ARRAY_OUT(1));

REG_CBS : CONTROL_REG

port map ( DIN => DIN_REG_CBS,

      ENABLE => ENABLE_REG_CBS,

      CLEAR => CLEAR,

      CLK => CLK,

      DOUT => ARRAY_OUT(2));

REG_CRC : CONTROL_REG

port map ( DIN => DIN_REG_CRC,

      ENABLE => ENABLE_REG_CRC,

      CLEAR => CLEAR,

      CLK => CLK,

      DOUT => ARRAY_OUT(3));

ENABLE_REG_CRC <= ENABLE_INT(3) when LOAD_CRC = '1' else '1';

DIN_REG_CRC <= DIN when LOAD_CRC = '1' else CRC_IN;

ENABLE_REG_CBS <= ENABLE_INT(2);

DIN_REG_CBS <= DIN;

ENABLE_REG_CR <= ENABLE_INT(0) when CLEAR_CR = '1' else '1'; -- clear the CR at the end of the decompression phase

DIN_REG_CR <= DIN when CLEAR_CR = '1' else "11111111111111111111111111111111";  -- clear the CR

CRC_OUT <= ARRAY_OUT(3);

C_BS_OUT <= ARRAY_OUT(2);

U_BS_OUT <= ARRAY_OUT(1);

START_D <= ARRAY_OUT(0)(12) or ARRAY_OUT(0)(15);  -- if both zeros engage decompression engine

STOP <= ARRAY_OUT(0)(14);

THRESHOLD_LEVEL <= ARRAY_OUT(0)(11 downto 4);

--THRESHOLD_LEVEL <= "00001000"; 

end LATCH;