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       = DECOMP_ASSEM_5  --
--  version      = 1.0           --
--  last update  = 7/01/00      --
--  author       = Jose Nunez    --
-----------------------------------
 
 
-- FUNCTION
-- Assembles input data and remaining valid data into 33 bit elements
-- for application to the decoder.
 
 
-- PIN LIST
-- OLD_DATA     = previous data available to the decoder.
-- OLD_LENGTH   = length of previous data available to the decoder.
-- MATCH_LENGTH = length of data matched by the decoder.
-- DATA_IN      = input data from external RAM.
-- NEW_DATA     = next data to be made available to the decoder.
-- NEW_LENGTH   = length of next data to be made available to the decoder.
-- UNDERFLOW    = indicates that more data is required from the RAM,
--                 i.e data presently on DATA_IN must be read.
 
 
library ieee,dzx;
use ieee.std_logic_1164.all;
use dzx.bit_arith.all;
use dzx.attributes.all;
 
entity DECOMP_ASSEM_9 is
port
(
      OLD_DATA : in bit_vector(132 downto 0) ;
      OLD_LENGTH : in bit_vector(6 downto 0) ;
 	  DECODING_UNDERFLOW : in bit;     
      MATCH_LENGTH : in bit_vector(5 downto 0) ;
      DATA_IN : in bit_vector(63 downto 0) ;
      NEW_DATA : out bit_vector(132 downto 0) ;
      NEW_LENGTH : out bit_vector(6 downto 0) ;
      UNDERFLOW : out bit 
);
 
end DECOMP_ASSEM_9;
 
 
 
architecture DEC_ASS of DECOMP_ASSEM_9 is
 
signal INT_UNDERFLOW : bit;   -- temporary underflow signal
signal TEMP_NEW_DATA_OUT : bit_vector(132 downto 0);
 
 
begin
 
LENGTH_CALC : process(OLD_LENGTH, MATCH_LENGTH, DECODING_UNDERFLOW)
 
variable NEW_LENGTH_AUX : bit_vector(6 downto 0);
variable TEMP_LENGTH : bit_vector(6 downto 0); 
begin
 
   TEMP_LENGTH := OLD_LENGTH;
 
   if (OLD_LENGTH < "0100011") then -- at least 35 bits. The other 35 are always present for a total of 70
		if(DECODING_UNDERFLOW = '0') then -- data in buffer
      		TEMP_LENGTH(6) := '1';
			NEW_LENGTH_AUX := TEMP_LENGTH - MATCH_LENGTH; -- current decoding operation takes place
		else
			NEW_LENGTH_AUX := TEMP_LENGTH; --current decoding operation not done			
		end if;
	   	INT_UNDERFLOW <= '0';
    else
		NEW_LENGTH_AUX := TEMP_LENGTH - MATCH_LENGTH;
      	INT_UNDERFLOW <= '1';
    end if;
 
    NEW_LENGTH <= NEW_LENGTH_AUX;
 
end process LENGTH_CALC;
 
 
CODE_CALC : process(OLD_DATA , OLD_LENGTH , DATA_IN)
variable TEMP_NEW_DATA : bit_vector(132 downto 0); 
 
begin
 
TEMP_NEW_DATA(132 downto 98) := OLD_DATA(132 downto 98);
 
case OLD_LENGTH is
    when "0000000" => TEMP_NEW_DATA(97 downto 0)  := DATA_IN & "0000000000000000000000000000000000";
    when "0000001" => TEMP_NEW_DATA(97 downto 0)  := OLD_DATA(97) & DATA_IN &  "000000000000000000000000000000000";
    when "0000010" => TEMP_NEW_DATA(97 downto 0)  := OLD_DATA(97 downto 96) & DATA_IN & "00000000000000000000000000000000";
    when "0000011" => TEMP_NEW_DATA(97 downto 0)  := OLD_DATA(97 downto 95) & DATA_IN & "0000000000000000000000000000000";
    when "0000100" => TEMP_NEW_DATA(97 downto 0)  := OLD_DATA(97 downto 94) & DATA_IN & "000000000000000000000000000000";
    when "0000101" => TEMP_NEW_DATA(97 downto 0)  := OLD_DATA(97 downto 93) & DATA_IN & "00000000000000000000000000000";
    when "0000110" => TEMP_NEW_DATA(97 downto 0)  := OLD_DATA(97 downto 92) & DATA_IN & "0000000000000000000000000000";
    when "0000111" => TEMP_NEW_DATA(97 downto 0)  := OLD_DATA(97 downto 91) & DATA_IN & "000000000000000000000000000";
    when "0001000" => TEMP_NEW_DATA(97 downto 0)  := OLD_DATA(97 downto 90) & DATA_IN & "00000000000000000000000000";
    when "0001001" => TEMP_NEW_DATA(97 downto 0)  := OLD_DATA(97 downto 89) & DATA_IN & "0000000000000000000000000";
    when "0001010" => TEMP_NEW_DATA(97 downto 0) := OLD_DATA(97 downto 88) & DATA_IN & "000000000000000000000000";
    when "0001011" => TEMP_NEW_DATA(97 downto 0) := OLD_DATA(97 downto 87) & DATA_IN & "00000000000000000000000";
    when "0001100" => TEMP_NEW_DATA(97 downto 0) := OLD_DATA(97 downto 86) & DATA_IN & "0000000000000000000000";
    when "0001101" => TEMP_NEW_DATA(97 downto 0) := OLD_DATA(97 downto 85) & DATA_IN & "000000000000000000000";
    when "0001110" => TEMP_NEW_DATA(97 downto 0) := OLD_DATA(97 downto 84) & DATA_IN & "00000000000000000000";
    when "0001111" => TEMP_NEW_DATA(97 downto 0) := OLD_DATA(97 downto 83) & DATA_IN & "0000000000000000000";
    when "0010000" => TEMP_NEW_DATA(97 downto 0) := OLD_DATA(97 downto 82) & DATA_IN & "000000000000000000";
    when "0010001" => TEMP_NEW_DATA(97 downto 0) := OLD_DATA(97 downto 81) & DATA_IN & "00000000000000000";
    when "0010010" => TEMP_NEW_DATA(97 downto 0) := OLD_DATA(97 downto 80) & DATA_IN & "0000000000000000";
    when "0010011" => TEMP_NEW_DATA(97 downto 0) := OLD_DATA(97 downto 79) & DATA_IN & "000000000000000";
    when "0010100" => TEMP_NEW_DATA(97 downto 0) := OLD_DATA(97 downto 78) & DATA_IN & "00000000000000";
    when "0010101" => TEMP_NEW_DATA(97 downto 0) := OLD_DATA(97 downto 77) & DATA_IN & "0000000000000";
    when "0010110" => TEMP_NEW_DATA(97 downto 0) := OLD_DATA(97 downto 76) & DATA_IN & "000000000000";
    when "0010111" => TEMP_NEW_DATA(97 downto 0) := OLD_DATA(97 downto 75) & DATA_IN & "00000000000";
    when "0011000" => TEMP_NEW_DATA(97 downto 0) := OLD_DATA(97 downto 74) & DATA_IN & "0000000000";
    when "0011001" => TEMP_NEW_DATA(97 downto 0) := OLD_DATA(97 downto 73) & DATA_IN & "000000000";
    when "0011010" => TEMP_NEW_DATA(97 downto 0) := OLD_DATA(97 downto 72) & DATA_IN & "00000000";
    when "0011011" => TEMP_NEW_DATA(97 downto 0) := OLD_DATA(97 downto 71) & DATA_IN & "0000000";
    when "0011100" => TEMP_NEW_DATA(97 downto 0) := OLD_DATA(97 downto 70) & DATA_IN & "000000";
    when "0011101" => TEMP_NEW_DATA(97 downto 0) := OLD_DATA(97 downto 69) & DATA_IN & "00000";
    when "0011110" => TEMP_NEW_DATA(97 downto 0) := OLD_DATA(97 downto 68) & DATA_IN & "0000";
    when "0011111" => TEMP_NEW_DATA(97 downto 0) := OLD_DATA(97 downto 67) & DATA_IN & "000";
    when "0100000" => TEMP_NEW_DATA(97 downto 0) := OLD_DATA(97 downto 66) & DATA_IN & "00";
	when "0100001" => TEMP_NEW_DATA(97 downto 0) := OLD_DATA(97 downto 65) & DATA_IN & "0";
	when "0100010" => TEMP_NEW_DATA(97 downto 0) := OLD_DATA(97 downto 64) & DATA_IN;
    when others   => TEMP_NEW_DATA(97 downto 0) := OLD_DATA(97 downto 0);
end case;
 
TEMP_NEW_DATA_OUT <= TEMP_NEW_DATA;
 
end process CODE_CALC;
 
 
MOVE: process(TEMP_NEW_DATA_OUT ,  MATCH_LENGTH)
 
begin
 
case MATCH_LENGTH is 
    when "000000" => NEW_DATA <= TEMP_NEW_DATA_OUT(132 downto 0); 
	when "000001" => NEW_DATA <= TEMP_NEW_DATA_OUT(131 downto 0)&'0';
	when "000010" => NEW_DATA <= TEMP_NEW_DATA_OUT(130 downto 0)&"00";
	when "000011" => NEW_DATA <= TEMP_NEW_DATA_OUT(129 downto 0)&"000";
	when "000100" => NEW_DATA <= TEMP_NEW_DATA_OUT(128 downto 0)&"0000";
	when "000101" => NEW_DATA <= TEMP_NEW_DATA_OUT(127 downto 0)&"00000";
	when "000110" => NEW_DATA <= TEMP_NEW_DATA_OUT(126 downto 0)&"000000";
	when "000111" => NEW_DATA <= TEMP_NEW_DATA_OUT(125 downto 0)&"0000000";
	when "001000" => NEW_DATA <= TEMP_NEW_DATA_OUT(124 downto 0)&"00000000";
	when "001001" => NEW_DATA <= TEMP_NEW_DATA_OUT(123 downto 0)&"000000000";
	when "001010" => NEW_DATA <= TEMP_NEW_DATA_OUT(122 downto 0)&"0000000000";
	when "001011" => NEW_DATA <= TEMP_NEW_DATA_OUT(121 downto 0)&"00000000000";
	when "001100" => NEW_DATA <= TEMP_NEW_DATA_OUT(120 downto 0)&"000000000000";
	when "001101" => NEW_DATA <= TEMP_NEW_DATA_OUT(119 downto 0)&"0000000000000";
	when "001110" => NEW_DATA <= TEMP_NEW_DATA_OUT(118 downto 0)&"00000000000000";
	when "001111" => NEW_DATA <= TEMP_NEW_DATA_OUT(117 downto 0)&"000000000000000";
	when "010000" => NEW_DATA <= TEMP_NEW_DATA_OUT(116 downto 0)&"0000000000000000";
	when "010001" => NEW_DATA <= TEMP_NEW_DATA_OUT(115 downto 0)&"00000000000000000";
	when "010010" => NEW_DATA <= TEMP_NEW_DATA_OUT(114 downto 0)&"000000000000000000";
	when "010011" => NEW_DATA <= TEMP_NEW_DATA_OUT(113 downto 0)&"0000000000000000000";
	when "010100" => NEW_DATA <= TEMP_NEW_DATA_OUT(112 downto 0)&"00000000000000000000";
	when "010101" => NEW_DATA <= TEMP_NEW_DATA_OUT(111 downto 0)&"000000000000000000000";
	when "010110" => NEW_DATA <= TEMP_NEW_DATA_OUT(110 downto 0)&"0000000000000000000000";
	when "010111" => NEW_DATA <= TEMP_NEW_DATA_OUT(109 downto 0)&"00000000000000000000000";
	when "011000" => NEW_DATA <= TEMP_NEW_DATA_OUT(108 downto 0)&"000000000000000000000000";
	when "011001" => NEW_DATA <= TEMP_NEW_DATA_OUT(107 downto 0)&"0000000000000000000000000";
	when "011010" => NEW_DATA <= TEMP_NEW_DATA_OUT(106 downto 0)&"00000000000000000000000000";
	when "011011" => NEW_DATA <= TEMP_NEW_DATA_OUT(105 downto 0)&"000000000000000000000000000";
	when "011100" => NEW_DATA <= TEMP_NEW_DATA_OUT(104 downto 0)&"0000000000000000000000000000";
	when "011101" => NEW_DATA <= TEMP_NEW_DATA_OUT(103 downto 0)&"00000000000000000000000000000";
	when "011110" => NEW_DATA <= TEMP_NEW_DATA_OUT(102 downto 0)&"000000000000000000000000000000";
	when "011111" => NEW_DATA <= TEMP_NEW_DATA_OUT(101 downto 0)&"0000000000000000000000000000000";
	when "100000" => NEW_DATA <= TEMP_NEW_DATA_OUT(100 downto 0)&"00000000000000000000000000000000";
	when "100001" => NEW_DATA <= TEMP_NEW_DATA_OUT(99 downto 0) &"000000000000000000000000000000000";
	when "100010" => NEW_DATA <= TEMP_NEW_DATA_OUT(98 downto 0) &"0000000000000000000000000000000000";
	when "100011" => NEW_DATA <= TEMP_NEW_DATA_OUT(97 downto 0) &"00000000000000000000000000000000000";
	when others => NEW_DATA <= TEMP_NEW_DATA_OUT;
	end case;
 
end process MOVE;
 
 
UNDERFLOW <= INT_UNDERFLOW;
 
 
 
end DEC_ASS;  -- end of architecture