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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_03_ch_03_08.vhd,v 1.3 2001-10-26 16:29:33 paw Exp $
-- $Revision: 1.3 $
--
-- ---------------------------------------------------------------------
entity ch_03_08 is
end entity ch_03_08;
architecture test of ch_03_08 is
begin
process_03_2_c : process is
-- code from book:
type opcodes is
(nop, add, subtract, load, store, jump, jumpsub, branch, halt);
subtype control_transfer_opcodes is opcodes range jump to branch;
-- end of code from book
variable opcode : opcodes;
variable operand : integer;
constant memory_operand : integer := 1;
constant address_operand : integer := 2;
begin
for i in opcodes loop
opcode := i;
-- code from book:
case opcode is
when load | add | subtract =>
operand := memory_operand;
when store | jump | jumpsub | branch =>
operand := address_operand;
when others =>
operand := 0;
end case;
--
case opcode is
when add to load =>
operand := memory_operand;
when branch downto store =>
operand := address_operand;
when others =>
operand := 0;
end case;
-- end of code from book
case opcode is
when add to load =>
operand := memory_operand;
-- code from book: (MTI bug mt011)
-- when control_transfer_opcodes | store =>
-- operand := address_operand;
-- end of code from book
when others =>
operand := 0;
end case;
end loop;
wait;
end process process_03_2_c;
end architecture test;
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