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       = SREG        --

--  version      = 1.0         --

--  last update  = 5/05/01    --

--  author       = Jose Nunez  --

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

-- FUNCTION

-- 32 bit wide search register

--  PIN LIST

--  DIN   = 32 bit input data

--  MIN  = 5 bit mask data

--  CLEAR = asynchronous clear of register

--  CLK   = clock

--  QOUT  = 32 bit output of flip-flops

--  QMOUT  = 5 bit mask out

library ieee,dzx;

use ieee.std_logic_1164.all;

entity SREG is

port

(

      DIN : in bit_vector(31 downto 0) ;

        MASK_IN : in bit_vector(4 downto 0);

      CLEAR : in bit ;

      CLK : in bit ;

        MASK_OUT : out bit_vector(4 downto 0);

      QOUT : out bit_vector(31 downto 0)

);

end SREG;

architecture LATCH of SREG is

begin

FLIP_FLOPS : process (CLK,CLEAR)

begin

        -- asynchronous RESET signal forces all outputs LOW

        if (CLEAR = '0') then

            QOUT <= x"00000000";

                MASK_OUT <= "00000";

            -- check for +ve clock edge

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

            -- check for synchronous clear signal

                    QOUT <= DIN;

                        MASK_OUT <= MASK_IN;

        end if;

end process FLIP_FLOPS;

end LATCH;