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       =  LOCATION_EQUAL    --

--  version      = 4.0         --

--  last update  = 11/02/98    --

--  author       = Jose Nunez  --

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

-- FUNCTION

-- Movement control multiplexor.

-- Selects either a compressed (A inputs) or decompressed

-- (B inputs) match location and full hit indicator and

-- makes them available on the Y outputs under the control

-- of SELB. If SELB=0 then B inputs are selected.

--  PIN LIST

-- A   = match location for compression

-- B   = match location for decompression

-- SELB = select 

-- ENABLEC = enable compression

-- ENABLED = enable decompression

-- Y   = match location output

library ieee,dzx;

use ieee.std_logic_1164.all;

use dzx.attributes.all;

entity LOCATION_EQUAL is

        port (

                  WRITE_ADDRESS_IN : in bit_vector(3 downto 0);

                  READ_ADDRESS_IN : in bit_vector(3 downto 0);

                  CLK : in bit;

                  CLEAR : in bit;

                  RESET : in bit;

                  ENABLE : in bit;

                  WRITE_ADDRESS_OUT : out bit_vector(3 downto 0);

                  READ_ADDRESS_OUT  : out bit_vector(7 downto 0);

              EQUAL : out bit);

end LOCATION_EQUAL;

architecture EQUALITY of LOCATION_EQUAL is

signal EQUAL_INT : bit;

signal EQUAL_AUX : bit;

begin

COMP : process (WRITE_ADDRESS_IN , READ_ADDRESS_IN, ENABLE)

begin

        if (WRITE_ADDRESS_IN = READ_ADDRESS_IN and ENABLE = '0')then

                EQUAL_INT <= '1';

                READ_ADDRESS_OUT <= "11111111";

        else

            EQUAL_INT <= '0';

         READ_ADDRESS_OUT <= "0000" & READ_ADDRESS_IN;

    end if;

end process COMP;

WRITE_ADDRESS_OUT <= WRITE_ADDRESS_IN;

FLIP_FLOP : process(CLK, CLEAR)

begin

        if(CLEAR = '0') then

                EQUAL_AUX <= '0';

        elsif ((CLK'event) and (CLK = '1')) then

                if(RESET = '0') then

                        EQUAL_AUX <= '0';

                elsif (ENABLE = '0') then

                        EQUAL_AUX <= EQUAL_INT;

                else

                        EQUAL_AUX <= EQUAL_AUX;

                end if;

        end if;

end process FLIP_FLOP;

EQUAL <= EQUAL_AUX;

end EQUALITY;