TwoComplementer.vhd
71 lines
| 2.8 KiB
| text/x-vhdl
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VhdlLexer
martin
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r147 | ------------------------------------------------------------------------------ | |
| -- This file is a part of the LPP VHDL IP LIBRARY | |||
| -- Copyright (C) 2009 - 2010, Laboratory of Plasmas Physic - CNRS | |||
| -- | |||
| -- This program 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 3 of the License, or | |||
| -- (at your option) any later version. | |||
| -- | |||
| -- This program 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 this program; if not, write to the Free Software | |||
| -- Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |||
| ------------------------------------------------------------------------------- | |||
| -- Author : Martin Morlot | |||
| -- Mail : martin.morlot@lpp.polytechnique.fr | |||
| ------------------------------------------------------------------------------- | |||
| library IEEE; | |||
| use IEEE.numeric_std.all; | |||
| use IEEE.std_logic_1164.all; | |||
| --! Programme permetant de compl�menter ou non les entr�es de l'ALU, et ainsi de travailler avec des nombres n�gatifs | |||
| entity TwoComplementer is | |||
| generic( | |||
| Input_SZ : integer := 16); | |||
| port( | |||
| clk : in std_logic; --! Horloge du composant | |||
| reset : in std_logic; --! Reset general du composant | |||
| clr : in std_logic; --! Un reset sp�cifique au programme | |||
| TwoComp : in std_logic; --! Autorise l'utilisation du compl�ment | |||
| OP : in std_logic_vector(Input_SZ-1 downto 0); --! Op�rande d'entr�e | |||
| RES : out std_logic_vector(Input_SZ-1 downto 0) --! R�sultat, op�rande compl�ment� ou non | |||
| ); | |||
| end TwoComplementer; | |||
| architecture ar_TwoComplementer of TwoComplementer is | |||
| signal REG : std_logic_vector(Input_SZ-1 downto 0); | |||
| signal OPinteger : integer; | |||
| signal RESCOMP : std_logic_vector(Input_SZ-1 downto 0); | |||
| begin | |||
| RES <= REG; | |||
| OPinteger <= to_integer(signed(OP)); | |||
| RESCOMP <= std_logic_vector(to_signed(-OPinteger,Input_SZ)); | |||
| process(clk,reset) | |||
| begin | |||
| if(reset='0')then | |||
| REG <= (others => '0'); | |||
| elsif(clk'event and clk='1')then | |||
| if(clr='1')then | |||
| REG <= (others => '0'); | |||
| elsif(TwoComp='1')then | |||
| REG <= RESCOMP; | |||
| else | |||
| REG <= OP; | |||
| end if; | |||
| end if; | |||
| end process; | |||
| end ar_TwoComplementer; |