CristalCaveGem » LustreC » Lustrec-Tests

-- 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_03_fg_03_04.vhd,v 1.3 2001-10-26 16:29:33 paw Exp $

-- $Revision: 1.3 $

--

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

entity counter is

  port ( clk, reset : in bit;  count : out natural );

end entity counter;

architecture behavior of counter is

begin

  incrementer : process is

                          variable count_value : natural := 0;

  begin

    count <= count_value;

    loop

      loop

        wait until clk = '1' or reset = '1';

        exit when reset = '1';

        count_value := (count_value + 1) mod 16;

        count <= count_value;

      end loop;

      -- at this point, reset = '1'

      count_value := 0;

      count <= count_value;

      wait until reset = '0';

    end loop;

  end process incrementer;

end architecture behavior;