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------------------------------------------------
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--! @file shift.vhd
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--! @brief RayTrac TestBench
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--! @author Julián Andrés Guarín Reyes
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--------------------------------------------------
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-- RAYTRAC
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-- Author Julian Andres Guarin
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-- shift.vhd
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-- This file is part of raytrac.
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--
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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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-- 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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--
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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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-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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-- GNU General Public License for more details.
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--
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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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library ieee;
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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_signed.all;
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use ieee.math_real.all;
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entity shifter is
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generic (
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address_width : integer := 9;
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width : integer := 32;
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even_shifter : string := "YES"
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);
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port (
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data : in std_logic_vector(width - 1 downto 0);
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exp : out std_logic_vector(integer(ceil(log(real(width),2.0)))-1 downto 0);
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address : out std_logic_vector (address_width-1 downto 0);
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zero : out std_logic
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);
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end shifter;
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architecture shifter_arch of shifter is
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-- signal datamask : std_logic_vector(width+address_width-1 downto 0);
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begin
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-- datamask (width+address_width-1 downto address_width) <= data(width-1 downto 0);
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-- datamask (address_width-1 downto 0) <= (others=>'0');
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sanityLost:
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process (data)
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variable index: integer range-1 to width+address_width-1:=width+address_width-1;
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begin
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address<=(others=>'0');
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exp<=(others=>'0');
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zero<=data(0);
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if even_shifter="YES" then
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index:=width-1;
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else
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index:=width-2;
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end if;
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while index>=1 loop
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if data(index)='1' then
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zero<='0';
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exp<=CONV_STD_LOGIC_VECTOR(index, exp'high+1);
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if index>=address_width then
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address <= data (index-1 downto index-address_width);
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else
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address(address_width-1 downto address_width-index) <= data (index-1 downto 0);
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address(address_width-index-1 downto 0) <= (others =>'0');
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end if;
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exit;
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end if;
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index:=index-2; --Boost
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end loop;
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end process sanityLost;
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-- process (data)
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-- begin
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-- if data=0 then
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-- zero<='1';
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-- else
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-- zero<='0';
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-- end if;
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-- end process;
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end shifter_arch;
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