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--! @file RLshifter.vhd
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--! @file RLshifter.vhd
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--! @brief RayTrac Arithmetic Shifter
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--! @brief RayTrac Arithmetic Shifter
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--! @author Julián Andrés Guarín Reyes
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--! @author Julián Andrés Guarín Reyes
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--------------------------------------------------
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--------------------------------------------------
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-- RAYTRAC
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-- RAYTRAC
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-- Author Julian Andres Guarin
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-- Author Julian Andres Guarin
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-- RLshifter.vhd
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-- RLshifter.vhd
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-- This file is part of raytrac.
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-- This file is part of raytrac.
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--
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--
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-- raytrac is free software: you can redistribute it and/or modify
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-- raytrac is free software: you can redistribute it and/or modify
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-- it under the terms of the GNU General Public License as published by
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-- it under the terms of the GNU General Public License as published by
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-- the Free Software Foundation, either version 3 of the License, or
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-- the Free Software Foundation, either version 3 of the License, or
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-- (at your option) any later version.
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-- (at your option) any later version.
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--
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--
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-- raytrac is distributed in the hope that it will be useful,
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-- raytrac is distributed in the hope that it will be useful,
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-- but WITHOUT ANY WARRANTY; without even the implied warranty of
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-- but WITHOUT ANY WARRANTY; without even the implied warranty of
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-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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-- GNU General Public License for more details.
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-- GNU General Public License for more details.
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--
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--
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-- You should have received a copy of the GNU General Public License
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-- You should have received a copy of the GNU General Public License
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-- along with raytrac. If not, see <http://www.gnu.org/licenses/>
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-- along with raytrac. If not, see <http://www.gnu.org/licenses/>
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library ieee;
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library ieee;
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use ieee.std_logic_1164.all;
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use ieee.std_logic_1164.all;
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use ieee.std_logic_arith.all;
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use ieee.std_logic_arith.all;
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use ieee.std_logic_unsigned.all;
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use ieee.std_logic_unsigned.all;
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use ieee.math_real.all;
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use ieee.math_real.all;
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--use work.arithpack.all;
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entity RLshifter is
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entity RLshifter is
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generic (
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generic (
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shiftFunction : string := "SQUARE_ROOT";
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shiftFunction : string := "SQUARE_ROOT";
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mantissa_width : integer := 18;
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mantissa_width : integer := 18;
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width : integer := 32
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width : integer := 32
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);
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);
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port (
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port (
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exp : in std_logic_vector (integer(ceil(log(real(width),2.0)))-1 downto 0);
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exp : in std_logic_vector (integer(ceil(log(real(width),2.0)))-1 downto 0);
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mantis : in std_logic_vector (mantissa_width-1 downto 0);
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mantis : in std_logic_vector (mantissa_width-1 downto 0);
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result : out std_logic_vector (width-1 downto 0)
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result : out std_logic_vector (width-1 downto 0)
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);
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);
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end RLshifter;
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end RLshifter;
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architecture RLshifter_arch of RLshifter is
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architecture RLshifter_arch of RLshifter is
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begin
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begin
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inverse:
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inverse:
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process (mantis,exp)
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process (mantis,exp)
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variable expi : integer ;
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variable expi : integer ;
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begin
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begin
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expi:= conv_integer(exp);
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expi:= conv_integer(exp);
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for i in width-1 downto 0 loop
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for i in width-1 downto 0 loop
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result(i)<='0';
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result(i)<='0';
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if shiftFunction="INVERSION" then
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if shiftFunction="INVERSION" then
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if i<=width-1-expi and i>=width-expi-mantissa_width then
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if i<=width-1-expi and i>=width-expi-mantissa_width then
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result(i)<=mantis(mantissa_width-width+expi+i);
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result(i)<=mantis(mantissa_width-width+expi+i);
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end if;
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end if;
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end if;
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end if;
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if shiftFunction="SQUARE_ROOT" then
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if shiftFunction="SQUARE_ROOT" then
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if i<=expi then
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if i<=expi then
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result(i)<=mantis(mantissa_width-1-expi+i);
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result(i)<=mantis(mantissa_width-1-expi+i);
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end if;
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end if;
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end if;
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end if;
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end loop;
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end loop;
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end process inverse;
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end process inverse;
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end RLshifter_arch;
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end RLshifter_arch;
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