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       = ASSEMBLER     --
--  version      = 2.0           --
--  last update  = 6/06/01       --
--  author       = Jose Nunez    --
-----------------------------------
 
 
-- FUNCTION
-- assembler for the uncompressed data.
 
 
-- PIN LIST
 
-- DATA_IN      = uncompressed data from the engine
-- MASK			= 4 bit indicating which bytes are valid
-- WRITE_OLD    = write operation done shift out used data
-- DATA_OLD		= 56 bits of old data
-- LENGTH_OLD   = length of old data
-- WRITE_NEW    = write data to buffer
-- DATA_NEW     = 56 bits of new data
-- LENGTH_NEW   = length of new data
 
 
 
 
library ieee,dzx;
use ieee.std_logic_1164.all;
use dzx.bit_arith.all;
use dzx.bit_utils.all; 
use dzx.attributes.all;
 
entity ASSEMBLER is
port
(
	ENABLE : in bit;
    DATA_IN : in bit_vector(31 downto 0);
	MASK_IN : in bit_vector(3 downto 0);
	DATA_OLD : in bit_vector(55 downto 0);
	LENGTH_OLD : in bit_vector(2 downto 0); --only 7 bytes
	DATA_NEW : out bit_vector(55 downto 0);
	LENGTH_NEW : out bit_vector(2 downto 0);
	WRITE : out bit
 
);
 
 
 
end ASSEMBLER;
 
 
architecture ASSEMBLE2 of ASSEMBLER is
 
begin
 
 
CALCULATE_LENGTH : process(ENABLE, MASK_IN, LENGTH_OLD)
variable TEMP_LENGTH : bit_vector(2 downto 0);
 
begin
 
TEMP_LENGTH := LENGTH_OLD;
 
if(TEMP_LENGTH(2) = '1') then
	 TEMP_LENGTH(2) := '0';
end if;
 
if (ENABLE = '0') then
 
	case MASK_IN is
 
	when "1000" =>
		TEMP_LENGTH := TEMP_LENGTH + "001";
	when "1100" =>
		TEMP_LENGTH := TEMP_LENGTH + "010";	
	when "1110" =>
		TEMP_LENGTH := TEMP_LENGTH + "011";	
	when "1111" =>
		TEMP_LENGTH := TEMP_LENGTH + "100";
	when others =>
		TEMP_LENGTH := TEMP_LENGTH;
 
	end case;
 
 
else
 
	TEMP_LENGTH := TEMP_LENGTH;	
 
end if;
 
 
WRITE <= TEMP_LENGTH(2);
LENGTH_NEW <= TEMP_LENGTH;
 
 
end process CALCULATE_LENGTH;
 
 
 
 
CONCATENATE_DATA : process(DATA_OLD, DATA_IN, LENGTH_OLD)
 
begin
 
	case LENGTH_OLD is
 
	when "000" => DATA_NEW <= DATA_IN & x"000000";
	when "001" => DATA_NEW <= DATA_OLD(55 downto 48) & DATA_IN & x"0000";
	when "010" => DATA_NEW <= DATA_OLD(55 downto 40) & DATA_IN & x"00";
	when "011" => DATA_NEW <= DATA_OLD(55 downto 32) & DATA_IN;
	when "100" => DATA_NEW <= DATA_IN & x"000000";
	when "101" => DATA_NEW <= DATA_OLD(23 downto 16) & DATA_IN & x"0000";
	when "110" => DATA_NEW <= DATA_OLD(23 downto 8) & DATA_IN & x"00";	
	when "111" => DATA_NEW <= DATA_OLD(23 downto 0) & DATA_IN;
 
	end case;
 
end process CONCATENATE_DATA;
 
 
 
end ASSEMBLE2; -- end of architecture