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-- 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_16_fg_16_02.vhd,v 1.2 2001-10-26 16:29:36 paw Exp $
-- $Revision: 1.2 $
--
-- ---------------------------------------------------------------------
entity processor is
end entity processor;
-- code from book
architecture rtl of processor is
subtype word is bit_vector(0 to 31);
type word_vector is array (natural range <>) of word;
function resolve_unique ( drivers : word_vector ) return word is
begin
return drivers(drivers'left);
end function resolve_unique;
signal source1, source2 : resolve_unique word register;
-- . . .
-- not in book
type alu_op_type is (pass1, pass2, add, subtract);
procedure perform_alu_op ( signal alu_opcode : in alu_op_type;
signal source1, source2 : in word;
signal destination : out word;
constant ignored : in integer := 0 ) is
begin
null;
end procedure perform_alu_op;
signal phase1, source1_reg_out_en,other_signal : bit;
signal alu_opcode : alu_op_type;
signal destination : word;
-- end not in book
begin
source1_reg : process (phase1, source1_reg_out_en, -- . . .) is
-- not in book
other_signal) is
-- end not in book
variable stored_value : word;
begin
-- . . .
if source1_reg_out_en = '1' and phase1 = '1' then
source1 <= stored_value;
-- not in book
stored_value := not stored_value;
-- end not in book
else
source1 <= null;
end if;
end process source1_reg;
alu : perform_alu_op ( alu_opcode, source1, source2, destination, -- . . . );
-- not in book
open );
-- end not in book
-- . . .
-- not in book
process is
begin
wait for 10 ns;
source1_reg_out_en <= '1';
phase1 <= '1', '0' after 10 ns;
wait for 20 ns;
source1_reg_out_en <= '1';
phase1 <= '1', '0' after 10 ns;
wait;
end process;
-- end not in book
end architecture rtl;
-- end code from book
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