---------------------------------------------------------------------------------                                                                           ----          X       X   XXXXXX    XXXXXX    XXXXXX    XXXXXX      X          ----          XX     XX  X      X  X      X  X      X  X           XX          ----          X X   X X  X         X      X  X      X  X          X X          ----          X  X X  X  X         X      X  X      X  X         X  X          ----          X   X   X  X          XXXXXX   X      X   XXXXXX      X          ----          X       X  X         X      X  X      X         X     X          ----          X       X  X         X      X  X      X         X     X          ----          X       X  X      X  X      X  X      X         X     X          ----          X       X   XXXXXX    XXXXXX    XXXXXX    XXXXXX      X          ----                                                                           ----                                                                           ----                       O R E G A N O   S Y S T E M S                       ----                                                                           ----                            Design & Consulting                            ----                                                                           -----------------------------------------------------------------------------------                                                                           ----         Web:           http://www.oregano.at/                             ----                                                                           ----         Contact:       mc8051@oregano.at                                  ----                                                                           -----------------------------------------------------------------------------------                                                                           ----  MC8051 - VHDL 8051 Microcontroller IP Core                               ----  Copyright (C) 2001 OREGANO SYSTEMS                                       ----                                                                           ----  This library is free software; you can redistribute it and/or            ----  modify it under the terms of the GNU Lesser General Public               ----  License as published by the Free Software Foundation; either             ----  version 2.1 of the License, or (at your option) any later version.       ----                                                                           ----  This library 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        ----  Lesser General Public License for more details.                          ----                                                                           ----  Full details of the license can be found in the file LGPL.TXT.           ----                                                                           ----  You should have received a copy of the GNU Lesser General Public         ----  License along with this library; if not, write to the Free Software      ----  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA  ----                                                                           ---------------------------------------------------------------------------------------         Author:                 Roland H鰈ler----         Filename:               addsub_cy_.vhd----         Date of Creation:       Mon Aug  9 12:14:48 1999----         Version:                $Revision: 1.4 $----         Date of Latest Version: $Date: 2002/01/07 12:17:44 $------         Description: Adder/Subtractor with carry/borrow and arbitrary--                      data width.---------------------------------------------------------------------------------------library IEEE; use IEEE.std_logic_1164.all; use IEEE.std_logic_arith.all;   -----------------------------ENTITY DECLARATION--------------------------------entity addsub_cy is  generic (DWIDTH : integer := 4);    port (opa_i    : in  std_logic_vector(DWIDTH-1 downto 0);   -- Operand A        opb_i    : in  std_logic_vector(DWIDTH-1 downto 0);   -- Operand B        addsub_i : in  std_logic;       -- Add or subtract command        cy_i     : in  std_logic;       -- Carry input        cy_o     : out std_logic;       -- Carry/borrow bit           rslt_o   : out std_logic_vector(DWIDTH-1 downto 0));  -- Result  end addsub_cy;