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_07_fg_07_13.vhd,v 1.2 2001-10-26 16:29:34 paw Exp $

-- $Revision: 1.2 $

--

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

entity fg_07_13 is

end entity fg_07_13;

architecture test of fg_07_13 is

  -- code from book

  procedure bv_lt ( bv1, bv2 : in bit_vector;  result : out boolean ) is

    variable tmp1 : bit_vector(bv1'range) := bv1;

    variable tmp2 : bit_vector(bv2'range) := bv2;

  begin

    tmp1(tmp1'left) := not tmp1(tmp1'left);

    tmp2(tmp2'left) := not tmp2(tmp2'left);

    result :=  tmp1 < tmp2;

  end procedure bv_lt;

  -- end code from book

begin

  stimulus : process is

                       subtype byte is bit_vector(0 to 7);

                     variable result : boolean;

  begin

    bv_lt( byte'(X"02"), byte'(X"04"), result );

    assert result;

    bv_lt( byte'(X"02"), byte'(X"02"), result );

    assert not result;

    bv_lt( byte'(X"02"), byte'(X"02"), result );

    assert not result;

    bv_lt( byte'(X"FC"), byte'(X"04"), result );

    assert result;

    bv_lt( byte'(X"04"), byte'(X"FC"), result );

    assert not result;

    bv_lt( byte'(X"FC"), byte'(X"FC"), result );

    assert not result;

    bv_lt( byte'(X"FC"), byte'(X"FE"), result );

    assert result;

    bv_lt( byte'(X"FE"), byte'(X"FC"), result );

    assert not result;

    wait;

  end process stimulus;

end architecture test;