-- Copyright (C) 1996 Morgan Kaufmann Publishers, Inc

-- This file is part of VESTs (Vhdl tESTs).

-- VESTs is free software; you can redistribute it and/or modify it
-- under the terms of the GNU General Public License as published by the
-- Free Software Foundation; either version 2 of the License, or (at
-- your option) any later version. 

-- VESTs 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 General Public License
-- for more details. 

-- You should have received a copy of the GNU General Public License
-- along with VESTs; if not, write to the Free Software Foundation,
-- Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 

-- ---------------------------------------------------------------------
--
-- $Id: ch_04_fg_04_01.vhd,v 1.3 2001-11-03 23:19:37 paw Exp $
-- $Revision: 1.3 $
--
-- ---------------------------------------------------------------------

-- not in book:
library ch4_pkgs;
use ch4_pkgs.pk_04_01.all;
-- end not in book


entity coeff_ram is
  port ( rd, wr : in bit;  addr : in coeff_ram_address;
  d_in : in real;  d_out : out real );
end entity coeff_ram;

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

architecture abstract of coeff_ram is
begin

  memory : process is
                     type coeff_array is array (coeff_ram_address) of real;
                   variable coeff : coeff_array;
  begin
    for index in coeff_ram_address loop
      coeff(index) := 0.0;
    end loop;
    loop
      wait on rd, wr, addr, d_in; 
      if rd = '1' then
        d_out <= coeff(addr);
      end if;
      if wr = '1' then
        coeff(addr) := d_in;
      end if;
    end loop;
  end process memory;

end architecture abstract;