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       = LC_ASSEMBLER --

--  version      = 1.0          --

--  last update  = 16/06/99     --

--  author       = Jose Nunez   --

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

-- FUNCTION

-- assembles literal characters into a left aligned format.

-- input match type determines which bytes are valid.

-- PIN LIST

-- MASK         = valid bytes

-- MATCH_TYPE   = input match type (active low), i.e a low indicates that the corresponding

--                byte in LITERAL_DATA is valid.

-- LITERAL_DATA = input literal data characters

-- CODE         = output bytes assembled in left justified format adding miss type if needed

-- LENGTH       = length of output code in bits

library ieee,dzx;

use ieee.std_logic_1164.all;

entity LC_ASSEMBLER is

port

(

    MASK : in bit_vector(4 downto 0);

        MATCH_TYPE : in bit_vector(3 downto 0);

    LITERAL_DATA : in bit_vector(31 downto 0);

        CODE : out bit_vector(33 downto 0);

        MISS : out bit;

        LENGTH : out bit_vector(5 downto 0)

);

end LC_ASSEMBLER;

architecture FIRST of LC_ASSEMBLER is

signal MISS_TYPE_CODE : bit_vector(33 downto 0);

signal MISS_TYPE_LENGTH : bit_vector(5 downto 0);

signal CODE_AUX : bit_vector(33 downto 0);

signal LENGTH_AUX : bit_vector(5 downto 0);

signal MISS_AUX : bit;

component MISS_TYPE_CODER

port

(

        MASK : in bit_vector(4 downto 0);

        LITERAL_DATA :in bit_vector(31 downto 0);

        CODE : out bit_vector(33 downto 0);

        LENGTH : out bit_vector(5 downto 0)

);

end component;

begin

MSS_CODER : MISS_TYPE_CODER

port map

(

        MASK => MASK,

        LITERAL_DATA => LITERAL_DATA,

        CODE => MISS_TYPE_CODE,

        LENGTH => MISS_TYPE_LENGTH

);

ASSEMBLE : process(MATCH_TYPE, LITERAL_DATA, MISS_TYPE_CODE, MISS_TYPE_LENGTH)

variable BYTE3 : bit_vector(7 downto 0);

variable BYTE2 : bit_vector(7 downto 0);

variable BYTE1 : bit_vector(7 downto 0);

variable BYTE0 : bit_vector(7 downto 0);

begin

BYTE3 := LITERAL_DATA(31 downto 24);

BYTE2 := LITERAL_DATA(23 downto 16);

BYTE1 := LITERAL_DATA(15 downto 8);

BYTE0 := LITERAL_DATA(7 downto 0);

case MATCH_TYPE is

    when "1111" => CODE_AUX <= MISS_TYPE_CODE;LENGTH_AUX <= MISS_TYPE_LENGTH;MISS_AUX <= '1';

    when "1110" => CODE_AUX <= MISS_TYPE_CODE;LENGTH_AUX <= MISS_TYPE_LENGTH;MISS_AUX <= '1';

    when "1101" => CODE_AUX <= MISS_TYPE_CODE;LENGTH_AUX <= MISS_TYPE_LENGTH;MISS_AUX <= '1';

    when "1100" => CODE_AUX <= BYTE3 & BYTE2 & "000000000000000000"; LENGTH_AUX <= "010000";MISS_AUX <= '0';

    when "1011" => CODE_AUX <= MISS_TYPE_CODE;LENGTH_AUX <= MISS_TYPE_LENGTH;MISS_AUX <= '1';

    when "1010" => CODE_AUX <= MISS_TYPE_CODE;LENGTH_AUX <= MISS_TYPE_LENGTH;MISS_AUX <= '1';

    when "1001" => CODE_AUX <= BYTE3 & BYTE0 & "000000000000000000"; LENGTH_AUX <= "010000";MISS_AUX <= '0';

    when "1000" => CODE_AUX <= BYTE3 & "00000000000000000000000000"; LENGTH_AUX <= "001000";MISS_AUX <= '0';

    when "0111" => CODE_AUX <= MISS_TYPE_CODE;LENGTH_AUX <= MISS_TYPE_LENGTH;MISS_AUX <= '1';

    when "0110" => CODE_AUX <= BYTE2 & BYTE1 & "000000000000000000"; LENGTH_AUX <= "010000";MISS_AUX <= '0';

    when "0101" => CODE_AUX <= MISS_TYPE_CODE;LENGTH_AUX <= MISS_TYPE_LENGTH;MISS_AUX <= '1';

    when "0100" => CODE_AUX <= BYTE2 & "00000000000000000000000000"; LENGTH_AUX <= "001000";MISS_AUX <= '0';

    when "0011" => CODE_AUX <= BYTE1 & BYTE0 & "000000000000000000"; LENGTH_AUX <= "010000";MISS_AUX <= '0';

    when "0010" => CODE_AUX <= BYTE1 & "00000000000000000000000000"; LENGTH_AUX <= "001000";MISS_AUX <= '0';

    when "0001" => CODE_AUX <= BYTE0 & "00000000000000000000000000"; LENGTH_AUX <= "001000";MISS_AUX <= '0';

    when "0000" => CODE_AUX <= "0000000000000000000000000000000000"; LENGTH_AUX <= "000000";MISS_AUX <= '0';

end case;

end process ASSEMBLE;

DECIDE : process ( CODE_AUX, LENGTH_AUX, MASK, MATCH_TYPE, MISS_AUX, MISS_TYPE_CODE, MISS_TYPE_LENGTH)

begin

if (MASK(1) = '1') then -- full word

        CODE <= CODE_AUX;

        LENGTH <= LENGTH_AUX;

        MISS <= MISS_AUX;

elsif (MATCH_TYPE = "0000") then -- partial word but full match

        CODE <= CODE_AUX;

        LENGTH <= LENGTH_AUX;

        MISS <= MISS_AUX;

else -- partial word and partial match

        CODE <= MISS_TYPE_CODE;

        LENGTH <= MISS_TYPE_LENGTH;

        MISS <= '1';

end if;

end process DECIDE;

end FIRST; -- end of architecture