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       = POINTER_FIRST    --

--  version      = 1.0              --

--  last update  = 9/05/00          --

--  author       = Jose Nunez       --

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

-- FUNCTION

-- pointer

--  PIN LIST

--  PREVIOUS = data from the previous location in the pointer array

--  CLEAR    = asynchronous clear of the data latches (active LOW)

--  CLK      = master clock

--  DOUT     = output of the data latches

library ieee;

use ieee.std_logic_1164.all;

entity POINTER_FIRST is

port

(

        PREVIOUS : in bit_vector(3 downto 0);

        MOVE_ENABLE : in bit;

        CLEAR : in bit ;

        RESET : in bit ;

        CLK : in bit ;

        DOUT : out bit_vector(3 downto 0)

);

end POINTER_FIRST;

architecture POINTER1 of POINTER_FIRST is

signal DOUT_AUX : bit_vector(3 downto 0);

begin

FLIP_FLOPS : process (CLK,CLEAR)

begin

     if (CLEAR = '0') then

            DOUT_AUX <= "0000";

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

        if (RESET = '0') then

                        DOUT_AUX <= "0000";

                elsif (MOVE_ENABLE = '0') then

                        DOUT_AUX <= PREVIOUS;

                else

                        DOUT_AUX <= DOUT_AUX;

                end if;

        end if;

end process FLIP_FLOPS;

DOUT <= DOUT_AUX;

end POINTER1;