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;