|
------------------------------------------------
|
|
--! @file fadd32.vhd
|
|
--! @brief RayTrac Floating Point Adder
|
|
--! @author Julián Andrés Guarín Reyes
|
|
--------------------------------------------------
|
|
|
|
|
|
-- RAYTRAC (FP BRANCH)
|
|
-- Author Julian Andres Guarin
|
|
-- fadd32.vhd
|
|
-- This file is part of raytrac.
|
|
--
|
|
-- raytrac 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.
|
|
--
|
|
-- raytrac 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 raytrac. If not, see <http://www.gnu.org/licenses/>
|
|
library ieee;
|
|
use ieee.std_logic_1164.all;
|
|
use ieee.std_logic_unsigned.all;
|
|
|
|
use work.arithpack.all;
|
|
|
|
--! Esta entidad recibe dos números en formato punto flotante IEEE 754, de precision simple y devuelve las mantissas signadas y corridas, y el exponente correspondiente al resultado antes de normalizarlo al formato float.
|
|
--!\nLas 2 mantissas y el exponente entran despues a la entidad add2 que suma las mantissas y entrega el resultado en formato IEEE 754.
|
|
entity fadd32 is
|
|
|
|
port (
|
|
clk,dpc : in std_logic;
|
|
a32,b32 : in xfloat32;
|
|
c32 : out xfloat32
|
|
);
|
|
end entity;
|
|
architecture fadd32_arch of fadd32 is
|
|
|
|
--! Altera Compiler Directive, to avoid m9k autoinferring thanks to the guys at http://www.alteraforum.com/forum/archive/index.php/t-30784.html ....
|
|
attribute altera_attribute : string;
|
|
attribute altera_attribute of fadd32_arch : architecture is "-name AUTO_SHIFT_REGISTER_RECOGNITION OFF";
|
|
|
|
|
|
--!TBXSTART:STAGE0
|
|
signal s0delta : std_logic_vector(7 downto 0);
|
|
signal s0a,s0b : std_logic_vector(31 downto 0); -- Float 32 bit
|
|
|
|
--!TBXEND
|
|
--!TBXSTART:STAGE1
|
|
signal s1zero : std_logic;
|
|
signal s1delta : std_logic_vector(5 downto 0);
|
|
signal s1exp : std_logic_vector(7 downto 0);
|
|
signal s1shifter,s1datab_8x : std_logic_vector(8 downto 0);
|
|
signal s1pl,s1datab : std_logic_vector(17 downto 0);
|
|
signal s1umantshift,s1umantfixed,s1postshift,s1xorslab : std_logic_vector(23 downto 0);
|
|
signal s1ph : std_logic_vector(26 downto 0);
|
|
--!TBXEND
|
|
--!TBXSTART:STAGE2
|
|
signal s2exp : std_logic_vector(7 downto 0);
|
|
signal s2xorslab : std_logic_vector(23 downto 0);
|
|
signal s2umantshift, s2mantfixed : std_logic_vector(24 downto 0);
|
|
--!TBXEND
|
|
--!TBXSTART:STAGE3
|
|
signal s3exp : std_logic_vector(7 downto 0);
|
|
signal s3mantfixed,s3mantshift : std_logic_vector (24 downto 0);
|
|
--!TBXEND
|
|
--!TBXSTART:STAGE4
|
|
signal s4exp : std_logic_vector (7 downto 0);
|
|
signal s4xorslab : std_logic_vector (24 downto 0);
|
|
signal s4sresult : std_logic_vector (25 downto 0);
|
|
--!TBXEND
|
|
--!TBXSTART:STAGE5
|
|
signal s5exp : std_logic_vector (7 downto 0);
|
|
signal s5result : std_logic_vector (25 downto 0);
|
|
--!TBXEND
|
|
|
|
--! LPM_MULTIPLIER
|
|
component lpm_mult
|
|
generic (
|
|
lpm_hint : string;
|
|
lpm_pipeline : natural;
|
|
lpm_representation : string;
|
|
lpm_type : string;
|
|
lpm_widtha : natural;
|
|
lpm_widthb : natural;
|
|
lpm_widthp : natural
|
|
);
|
|
port (
|
|
dataa : in std_logic_vector ( lpm_widtha-1 downto 0 );
|
|
datab : in std_logic_vector ( lpm_widthb-1 downto 0 );
|
|
result : out std_logic_vector( lpm_widthp-1 downto 0 )
|
|
);
|
|
end component;
|
|
|
|
|
|
|
|
|
|
|
|
begin
|
|
|
|
process (clk)
|
|
begin
|
|
if clk'event and clk='1' then
|
|
|
|
--!Registro de entrada
|
|
s0a <= a32;
|
|
s0b(31) <= dpc xor b32(31); --! Importante: Integrar el signo en el operando B
|
|
s0b(30 downto 0) <= b32(30 downto 0);
|
|
|
|
--!Etapa 0,Escoger el mayor exponente que sera el resultado desnormalizado, calcula cuanto debe ser el corrimiento de la mantissa con menor exponente y reorganiza los operandos, si el mayor es b, intercambia las posición si el mayor es a las posiciones la mantiene. Zero check.
|
|
--!signo,exponente,mantissa
|
|
if (s0b(30 downto 23)&s0a(30 downto 23))=x"0000" then
|
|
s1zero <= '0';
|
|
else
|
|
s1zero <= '1';
|
|
end if;
|
|
s1delta <= s0delta(7) & (s0delta(7) xor s0delta(4))&(s0delta(7) xor s0delta(3)) & s0delta(2 downto 0);
|
|
case s0delta(7) is
|
|
when '1' =>
|
|
s1exp <= s0b(30 downto 23);
|
|
s1umantshift <= s0a(31)&s0a(22 downto 0);
|
|
s1umantfixed <= s0b(31)&s0b(22 downto 0);
|
|
when others =>
|
|
s1exp <= s0a(30 downto 23);
|
|
s1umantshift <= s0b(31)&s0b(22 downto 0);
|
|
s1umantfixed <= s0a(31)&s0a(22 downto 0);
|
|
end case;
|
|
|
|
--! Etapa 1: Denormalización de la mantissas.
|
|
case s1delta(4 downto 3) is
|
|
when "00" => s2umantshift <= s1umantshift(23)&s1postshift(23 downto 0);
|
|
when "01" => s2umantshift <= s1umantshift(23)&x"00"&s1postshift(23 downto 8);
|
|
when "10" => s2umantshift <= s1umantshift(23)&x"0000"&s1postshift(23 downto 16);
|
|
when others => s2umantshift <= (others => '0');
|
|
end case;
|
|
|
|
s2mantfixed <= s1umantfixed(23) & ( ( ('1'&s1umantfixed(22 downto 0)) xor s1xorslab) + ( x"00000"&"000"&s1umantfixed(23) ) );
|
|
s2exp <= s1exp;
|
|
|
|
--! Etapa2: Signar la mantissa denormalizada.
|
|
s3mantfixed <= s2mantfixed;
|
|
s3mantshift <= s2umantshift(24)& ( ( s2umantshift(23 downto 0) xor s2xorslab) + ( x"00000"&"000"&s2umantshift(24) ) );
|
|
s3exp <= s2exp;
|
|
|
|
--! Etapa 3: Etapa 3 Realizar la suma, entre la mantissa corrida y la fija.
|
|
s4sresult <= (s3mantshift(24)&s3mantshift)+(s3mantfixed(24)&s3mantfixed);
|
|
s4exp <= s3exp;
|
|
|
|
--! Etapa 4: Quitar el signo a la mantissa resultante.
|
|
s5result <= s4sresult(25)&((s4sresult(24 downto 0) xor s4xorslab) +(x"000000"&s4sresult(25)));
|
|
s5exp <= s4exp;
|
|
|
|
|
|
|
|
|
|
|
|
|
|
end if;
|
|
end process;
|
|
--! Etapa 5: Codificar el corrimiento para la normalizacion de la mantissa resultante y entregar el resultado.
|
|
c32(31) <= s5result(25);
|
|
process (s5result(24 downto 0),s5exp)
|
|
begin
|
|
case s5result(24) is
|
|
when '1' =>
|
|
c32 (22 downto 00) <= s5result(23 downto 1);
|
|
c32 (30 downto 23) <= s5exp+1;
|
|
when others =>
|
|
c32 (22 downto 00) <= s5result(22 downto 0);
|
|
c32 (30 downto 23) <= s5exp;
|
|
end case;
|
|
end process;
|
|
|
|
|
|
--! Combinatorial gremlin, Etapa 0 el corrimiento de la mantissa con menor exponente y reorganiza los operandos,\n
|
|
--! si el mayor es b, intercambia las posición si el mayor es a las posiciones la mantiene.
|
|
s0delta <= s0a(30 downto 23)-s0b(30 downto 23);
|
|
--! Combinatorial Gremlin, Etapa 1 Codificar el factor de corrimiento de denormalizacion y denormalizar la mantissa no fija. Signar la mantissa que se queda fija.
|
|
decodeshiftfactor:
|
|
process (s1delta(2 downto 0))
|
|
begin
|
|
case s1delta(2 downto 0) is
|
|
when "111" => s1shifter(8 downto 0) <= '0'&s1delta(5)&"00000"¬(s1delta(5))&'0';
|
|
when "110" => s1shifter(8 downto 0) <= "00"&s1delta(5)&"000"¬(s1delta(5))&"00";
|
|
when "101" => s1shifter(8 downto 0) <= "000"&s1delta(5)&'0'¬(s1delta(5))&"000";
|
|
when "100" => s1shifter(8 downto 0) <= '0'&x"10";
|
|
when "011" => s1shifter(8 downto 0) <= "000"¬(s1delta(5))&'0'&s1delta(5)&"000";
|
|
when "010" => s1shifter(8 downto 0) <= "00"¬(s1delta(5))&"000"&s1delta(5)&"00";
|
|
when "001" => s1shifter(8 downto 0) <= '0'¬(s1delta(5))&"00000"&s1delta(5)&'0';
|
|
when others => s1shifter(8 downto 0) <= not(s1delta(5))&"0000000"&s1delta(5);
|
|
end case;
|
|
end process;
|
|
s1datab <= s1zero&s1umantshift(22 downto 06);
|
|
denormhighshiftermult:lpm_mult
|
|
generic map (
|
|
lpm_hint => "DEDICATED_MULTIPLIER_CIRCUITRY=YES,MAXIMIZE_SPEED=9",
|
|
lpm_pipeline => 0,
|
|
lpm_representation => "UNSIGNED",
|
|
lpm_type => "LPM_MULT",
|
|
lpm_widtha => 9,
|
|
lpm_widthb => 18,
|
|
lpm_widthp => 27
|
|
)
|
|
port map (
|
|
dataa => s1shifter,
|
|
datab => s1datab,
|
|
result => s1ph
|
|
);
|
|
s1datab_8x <= s1umantshift(5 downto 0)&"000";
|
|
denormlowshiftermult:lpm_mult
|
|
generic map (
|
|
lpm_hint => "DEDICATED_MULTIPLIER_CIRCUITRY=YES,MAXIMIZE_SPEED=9",
|
|
lpm_pipeline => 0,
|
|
lpm_representation => "UNSIGNED",
|
|
lpm_type => "LPM_MULT",
|
|
lpm_widtha => 9,
|
|
lpm_widthb => 9,
|
|
lpm_widthp => 18
|
|
)
|
|
port map (
|
|
dataa => s1shifter,
|
|
datab(8 downto 0) => s1datab_8x,
|
|
result => s1pl
|
|
);
|
|
|
|
s1postshift(23 downto 7) <= s1ph(25 downto 9);
|
|
s1postshift(06 downto 0) <= s1ph(08 downto 2) or s1pl(17 downto 11);
|
|
s1xorslab(23 downto 0) <= (others => s1umantfixed(23));
|
|
|
|
--! Combinatorial Gremlin, Etapa 2: Signar la mantissa denormalizada.
|
|
s2xorslab <= (others => s2umantshift(24));
|
|
|
|
--! Combinatorial Gremlin, Etapa 4: Quitar el signo de la mantissa resultante.
|
|
s4xorslab <= (others => s4sresult(25));
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
end architecture;
|
|
|
|
|
No newline at end of file
|
No newline at end of file
|