Subversion Repositories raytrac

--! @file raytrac.vhd

--! @brief Sistema de Procesamiento Vectorial. La interface es compatible con el bus Avalon de Altera.  

--! @author Julián Andrés Guarín Reyes

--------------------------------------------------------------

-- RAYTRAC

-- Author Julian Andres Guarin

-- raytrac.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;

library altera_mf;

use altera_mf.altera_mf_components.all;

library lpm;

use lpm.lpm_components.all;

entity raytrac is

        generic (

                wd      :       integer := 32;

                fd      :       integer := 8;   --! Result Fifo Depth = 2**fd =256

                mb      :       integer := 4    --! Max Burst Length = 2**mb            

        );

        port (

                clk:    in std_logic;

                rst:    in std_logic;

                --! Avalon MM Slave

                slave_address                   :       in      std_logic_vector(3 downto 0);

                slave_read                              :       in      std_logic;

                slave_write                             :       in      std_logic;

                slave_readdata                  :       out std_logic_vector(31 downto 0);

                slave_writedata                 :       in      std_logic_vector(31 downto 0);

                --! Avalon MM Master (Read & Write common signals)      

                master_address                  :       out std_logic_vector(31 downto 0);

                master_burstcount               :       out std_logic_vector(4 downto 0);

                master_waitrequest              :       in      std_logic;

                --! Avalon MM Master (Read Stage)

                master_read                             :       out     std_logic;

                master_readdata                 :       in      std_logic_vector(31 downto 0);

                master_readdatavalid    :       in      std_logic;

                --! Avalon MM Master (Write Stage)

                master_write                    :       out     std_logic;

                master_writedata                :       out std_logic_vector(31 downto 0);

                --! Avalon IRQ

                irq                                             :       out std_logic

        );

end entity;

architecture raytrac_arch of raytrac 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 raytrac_arch : architecture is "-name AUTO_SHIFT_REGISTER_RECOGNITION OFF";

        type    registerblock   is array (15 downto 0) of xfloat32;

        type    transferState   is (IDLE,SINK,SOURCE);

        type    upload_chain    is (UPVX,UPVY,UPVZ,SC,DMA);

        type    download_chain  is (DWAX,DWAY,DWAZ,DWBX,DWBY,DWBZ,DWAXBX,DWAYBY,DWAZBZ);

        constant reg_ctrl                               :       integer:=00;

        constant reg_vz                                 :       integer:=01;

        constant reg_vy                                 :       integer:=02;

        constant reg_vx                                 :       integer:=03;

        constant reg_scalar                             :       integer:=04;

        constant reg_scratch00                  :       integer:=05;

        constant reg_outputcounter              :       integer:=06;

        constant reg_inputcounter               :       integer:=07;

        constant reg_fetchstart                 :       integer:=08;

        constant reg_sinkstart                  :       integer:=09;

        constant reg_ax                                 :       integer:=10;

        constant reg_ay                                 :       integer:=11;

        constant reg_az                                 :       integer:=12;

        constant reg_bx                                 :       integer:=13;

        constant reg_by                                 :       integer:=14;

        constant reg_bz                                 :       integer:=15;

        constant reg_ctrl_cmb                   :       integer:=00;    --! CMB bit : Combinatorial Instruction.

        constant reg_ctrl_s                             :       integer:=01;    --! S bit of the DCS field.

        constant reg_ctrl_c                             :       integer:=02;    --! C bit of the DCS field.

        constant reg_ctrl_d                             :       integer:=03;    --! D bit of the DCS field.

        constant reg_ctrl_sc                    :       integer:=04;    --! SC bit of the VTSC field.

        constant reg_ctrl_vt                    :       integer:=05;    --! VT bit of the VTSC field.

        constant reg_ctrl_dma                   :       integer:=06;    --! DMA bit.

        constant reg_ctrl_flags_fc              :       integer:=07;    --! Flood Condition Flag.

        constant reg_ctrl_flags_dc              :       integer:=08;    --! Drain Condition Flag.       

        constant reg_ctrl_flags_wp              :       integer:=09;    --! Write on Memory Pending Flag.

        constant reg_ctrl_flags_pp              :       integer:=10;    --! Pipeline Pending Flag.

        constant reg_ctrl_flags_pl              :       integer:=11;    --! Load Parameter Pending Flag.

        constant reg_ctrl_flags_dp              :       integer:=12;    --! Data Pending flag.

        constant reg_ctrl_flags_ap              :       integer:=13;    --! Address Pending Flag.

        constant reg_ctrl_rlsc                  :       integer:=14;    --! RLSC bit : Reload Load Sync Chain.

        constant reg_ctrl_rom                   :       integer:=15;    --! ROM bit : Read Only Mode bit.

        constant reg_ctrl_alb                   :       integer:=16;    --! Conditional Writing. A<B.

        constant reg_ctrl_aeb                   :       integer:=17;    --! A==B.

        constant reg_ctrl_ageb                  :       integer:=18;    --! A>=B.

        constant reg_ctrl_nfetch_low    :       integer:=19;    --! NFETCH_LOW : Lower bit to program the number of addresses to load in the interconnection.

        constant reg_ctrl_nfetch_high   :       integer:=30;    --! NFETCH_HIGH : Higher bit to program the number of addresses to load in the interconnection. 

        constant reg_ctrl_irq                   :       integer:=31;    --! IRQ bit : Interrupt Request Signal.

        --! Avalon MM Slave

        signal  sreg_block                      :       registerblock;

        signal  sslave_read                     :       std_logic;

        signal  sslave_write            :       std_logic;

        signal  sslave_writedata        :       std_logic_vector (wd-1 downto 0);

        signal  sslave_address          :       std_logic_vector (3 downto 0);

        signal  sslave_waitrequest      :       std_logic;

        --! Avalon MM Master

        signal  smaster_write           :       std_logic;

        signal  smaster_read            :       std_logic;

        --! State Machine and event signaling

        signal sm                                       :       transferState;

        signal sr_e                                     :       std_logic;

        signal sr_ack                           :       std_logic;

        signal soutb_ack                        :       std_logic;

        signal soutb_d                          :       std_logic_vector(wd-1 downto 0);

        signal soutb_w                          :       std_logic;

        signal soutb_e                          :       std_logic;

        signal soutb_ae                         :       std_logic;

        signal soutb_af                         :       std_logic;

        signal soutb_usedw                      :       std_logic_vector(fd-1 downto 0);

        signal ssync_chain_1            :       std_logic;

        signal ssync_chain_pending      :       std_logic;

        signal sfetch_data_pending      :       std_logic;

        signal sload_add_pending        :       std_logic;

        signal spipeline_pending        :       std_logic;

        signal swrite_pending           :   std_logic;

        signal sparamload_pending       :       std_logic;

        signal sZeroTransit                     :       std_logic;

        --!Unload Control

        signal supload_chain    : upload_chain;

        signal supload_start    : upload_chain;

        --!Señales de apoyo:

        signal zero : std_logic_vector(31 downto 0);

        --!High Register Bank Control Signals or AKA Load Sync Chain Control

        signal sdownload_chain  : download_chain;

        signal sdownload_start  : download_chain;

        signal srestart_chain   : std_logic;

        --!State Machine Hysteresis Control Signals

        signal sdrain_condition         : std_logic;

        signal sdrain_burstcount        : std_logic_vector(mb downto 0);

        signal sdata_fetch_counter      : std_logic_vector(reg_ctrl_nfetch_high downto reg_ctrl_nfetch_low);

        signal sburstcount_sink         : std_logic_vector(mb downto 0);

        signal sflood_condition         : std_logic;

        signal sflood_burstcount        : std_logic_vector(mb downto 0);

        --! Arithmetic Pipeline and Data Path Control

        component ap_n_dpc

        port (

                clk                                             : in    std_logic;

                rst                                             : in    std_logic;

                ax                                              : in    std_logic_vector(31 downto 0);

                ay                                              : in    std_logic_vector(31 downto 0);

                az                                              : in    std_logic_vector(31 downto 0);

                bx                                              : in    std_logic_vector(31 downto 0);

                by                                              : in    std_logic_vector(31 downto 0);

                bz                                              : in    std_logic_vector(31 downto 0);

                vx                                              : out   std_logic_vector(31 downto 0);

                vy                                              : out   std_logic_vector(31 downto 0);

                vz                                              : out   std_logic_vector(31 downto 0);

                sc                                              : out   std_logic_vector(31 downto 0);

                ack                                             : in    std_logic;

                empty                                   : out   std_logic;

                dcs                                             : in    std_logic_vector(2 downto 0);            --! Bit con el identificador del bloque AB vs CD e identificador del sub bloque (A/B) o (C/D). 

                sync_chain_1                    : in    std_logic;              --! Señal de dato valido que se va por toda la cadena de sincronizacion.

                pipeline_pending                : out   std_logic               --! Señal para indicar si hay datos en el pipeline aritmético.    

        );

        end component;

        --! Nets para la salida de la cola de resultados y entrada del multiplexor del upload state machine.

        signal svx,svy,svz,ssc          : std_logic_vector(31 downto 0);

begin

        --!Zero agreggate

        zero    <= (others => '0');

--! *************************************************************************************************************************************************************************************************************************************************************

--! ARITHMETIC PIPELINE AND DATA PATH INSTANTIATION  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  =>  => 

--! *************************************************************************************************************************************************************************************************************************************************************

        --! Arithpipeline and Datapath Control Instance

        arithmetic_pipeline_and_datapath_controller : ap_n_dpc

        port map (

                clk                             => clk,

                rst                             => rst,

                ax                                      => sreg_block(reg_ax),

                ay                                      => sreg_block(reg_ay),

                az                                      => sreg_block(reg_az),

                bx                                      => sreg_block(reg_bx),

                by                                      => sreg_block(reg_by),

                bz                                      => sreg_block(reg_bz),

                vx                                      => svx,

                vy                                      => svy,

                vz                                      => svz,

                sc                                      => ssc,

                ack                                     => sr_ack,

                empty                           => sr_e,

                dcs                                     => sreg_block(reg_ctrl)(reg_ctrl_d downto reg_ctrl_s),

                sync_chain_1            => ssync_chain_1,

                pipeline_pending        => spipeline_pending

        );

--! ******************************************************************************************************************************************************                                              

--! TRANSFER CONTROL RTL CODE

--! ******************************************************************************************************************************************************                                              

        TRANSFER_CONTROL:

        process(clk,rst,master_waitrequest,sm,soutb_ae,soutb_usedw,spipeline_pending,soutb_e,zero,soutb_af,sfetch_data_pending,sreg_block,sslave_write,sslave_address,sslave_writedata,ssync_chain_pending,smaster_read,smaster_write,sdata_fetch_counter,sload_add_pending,swrite_pending,sdownload_chain)

        begin

                --! Conexi&oacuteln a señales externas. 

                irq <= sreg_block(reg_ctrl)(reg_ctrl_irq);

                master_read <= smaster_read;

                master_write <= smaster_write;

                --! Direct Memory Access Selector.

                --! ZERO_TRANSIT: Cuando todos los elementos de sincronización están en cero menos la cola de sincronización de carga de parametros.

                sZeroTransit <= not(sload_add_pending or sfetch_data_pending or spipeline_pending or swrite_pending);

                --! ELEMENTO DE SINCRONIZACION OUT QUEUE: Datos pendientes por cargar a la memoria a través de la interconexión

                swrite_pending <= not(soutb_e);

                --! ELEMENTO DE SINCRONIZACION DESCARGA DE DATOS: Hay datos pendientes por descargar desde la memoria a través de la interconexión.

                if sdata_fetch_counter=zero(reg_ctrl_nfetch_high downto reg_ctrl_nfetch_low) then

                        sfetch_data_pending <= '0';

                else

                        sfetch_data_pending <= '1';

                end if;

                --! ELEMENTO DE SINCRONIZACION CARGA DE DIRECCIONES: Hay direcciones pendientes por cargar a la interconexión?

                if sreg_block(reg_ctrl)(reg_ctrl_nfetch_high downto reg_ctrl_nfetch_low)=zero(reg_ctrl_nfetch_high downto reg_ctrl_nfetch_low) then

                        sload_add_pending <= '0';

                else

                        sload_add_pending <= '1';

                end if;

                --! ELEMENTO DE SINCRONIZACION CARGA DE OPERANDOS: Se están cargando los operandos que serán operados en el pipeline aritmético.

                if sdownload_chain /= DWAX and sdownload_chain /= DWAXBX then

                        sparamload_pending <= '1';

                else

                        sparamload_pending <= '0';

                end if;

                --! Se debe iniciar una transacción de descarga de datos desde la memoria externa?

                if soutb_af='0' and sload_add_pending='1' then

                        --! Flow Control : La saturación de la cola de resultados continuará si no está tan llena y además hay pendientes datos por ser descargados.

                        sflood_condition <= '1';

                else

                        --! Flow Control : La saturación de la cola de resultados debe parar porque está casí llena.       

                        sflood_condition <= '0';

                end if;

                if sreg_block(reg_ctrl)(reg_ctrl_nfetch_high downto reg_ctrl_nfetch_low+mb)/=zero(reg_ctrl_nfetch_high downto reg_ctrl_nfetch_low+mb) then

                        --! Flow Control: Si el número de descargas pendientes es mayor o igual al max burst length, entonces cargar max burst en el contador.

                        sflood_burstcount <= '1'&zero(mb-1 downto 0);

                else

                        --! Flow Control: Si le número de descargas pendientes es inferior a Max Burst Count entonces cargar los bits menos significativos del registro de descargas pendientes.

                        sflood_burstcount <= '0'&sreg_block(reg_ctrl)(reg_ctrl_nfetch_low+mb-1 downto reg_ctrl_nfetch_low);

                end if;

                --! Se debe iniciar una transacción de carga de datos hacia la memoria externa?

                if soutb_ae='1' then

                        --! Flow Control : Cuando se esté drenando la cola de resultados, si la cola está casí vac&iaute;a, la longitud del burst serán los bits menos significativos del contador de la cola.  

                        sdrain_burstcount <= soutb_usedw(mb downto 0);

                        --! Flow Control: El drenado de datos continuará si el número de datos en la cola bajo y no hay datos transitando por el pipeline, ni datos pendientes por cargar desde la memoria.   

                        sdrain_condition <= not(sload_add_pending) and not(sfetch_data_pending) and not(spipeline_pending) and swrite_pending;

                else

                        --! Flow Control: Cuando se esté drenando la cola de resultados, si la cola de tiene una cantidad de datos mayor al burst count entonces se hará una transacción de longitud equivalente al burst count.

                        sdrain_burstcount <= '1'&zero(mb-1 downto 0);

                        --! Flow Control: El drenado de datos continuará si el número de datos en la cola es mayor o igual a 2**mb O si hay muy pocos datos y no hay datos transitando por el pipeline.   

                        sdrain_condition <= '1';

                end if;

                --! Restart param load chain

                srestart_chain <= sreg_block(reg_ctrl)(reg_ctrl_irq) and sreg_block(reg_ctrl)(reg_ctrl_rlsc);

                --! Data dumpster: Descaratar dato de upload una vez la interconexión haya enganchado el dato.

                if sm=SINK and master_waitrequest='0' and smaster_write='1' then

                        soutb_ack <= '1';

                else

                        soutb_ack <= '0';

                end if;

                --! Flow Control State Machine.

                if rst=rstMasterValue then

                        --! State Machine 

                        sm <= IDLE;

                        --! Master Write & Read Common Signals Reset Value

                        master_burstcount       <= (others => '0');

                        master_address          <= (others => '0');

                        sdata_fetch_counter     <= (others => '0');

                        sburstcount_sink        <= (others => '0');

                        --! Master Read Only Signals Reset Value

                        smaster_read            <= '0';

                        --! Master Write Only Signals

                        smaster_write           <= '0';

                        --! Reg Ctrl & Fetch address and writeaddress

                        --! Sinking address

                        sreg_block(reg_sinkstart) <= (others => '0');

                        --! Sourcing address

                        sreg_block(reg_fetchstart) <= (others => '0');

                        --! Control and Status Register

                        sreg_block(reg_ctrl) <= (others => '0');

                        --! Contador Overall

                        sreg_block(reg_inputcounter) <= (others => '0');

                        sreg_block(reg_outputcounter) <= (others => '0');

                elsif clk'event and clk='1' then

                        --! Nevermind the State, discount the incoming valid data counter.

                        sdata_fetch_counter <= sdata_fetch_counter-master_readdatavalid;

                        --! Debug Counter.

                        sreg_block(reg_inputcounter) <= sreg_block(reg_inputcounter) + master_readdatavalid;

                        sreg_block(reg_outputcounter) <= sreg_block(reg_outputcounter) + soutb_ack;

                        --! Flags

                        case sm is

                                when SOURCE =>

                                        --! ******************************************************************************************************************************************************                                              

                                        --! Flooding the pipeline ........

                                        --! ******************************************************************************************************************************************************                                              

                                        if smaster_read='0' then

                                                if sflood_condition = '1' then

                                                        --! Flow Control: Hay suficiente espacio en el buffer de salida y hay descargas pendientes por hacer

                                                        smaster_read <= '1';

                                                        master_address <= sreg_block(reg_fetchstart);

                                                        master_burstcount <= sflood_burstcount;

                                                        sdata_fetch_counter <= sdata_fetch_counter+sflood_burstcount-master_readdatavalid;

                                                        --! Context Saving:

                                                        sreg_block(reg_fetchstart) <= sreg_block(reg_fetchstart) + (sflood_burstcount&"00");

                                                        sreg_block(reg_ctrl)(reg_ctrl_nfetch_high downto reg_ctrl_nfetch_low) <= sreg_block(reg_ctrl)(reg_ctrl_nfetch_high downto reg_ctrl_nfetch_low) - sflood_burstcount;

                                                else

                                                        --! Flow Control : Cambiar al estado SINK, porque o está muy llena la cola de salida o no hay descargas pendientes por realizar.

                                                        sm <= SINK;

                                                end if;

                                        else --master_read=1;

                                                if master_waitrequest='0' then

                                                        --! Las direcciones de lectura están cargadas. Terminar la transferencia.

                                                        smaster_read <= '0';

                                                end if;

                                        end if;

                                when SINK =>

                                        --! ******************************************************************************************************************************************************                                              

                                        --! Draining the pipeline ........

                                        --! ******************************************************************************************************************************************************                                              

                                        if smaster_write='0' then

                                                if sdrain_condition='1' then

                                                        --! Flow Control : Hay muchos datos aun en la cola de resultados Ó la cola de resultados está casí vacía y no hay datos transitando en el pipeline aritm&eetico.

                                                        smaster_write <= '1';

                                                        master_address <= sreg_block(reg_sinkstart);

                                                        master_burstcount <= sdrain_burstcount;

                                                        --!Context Saving

                                                        sreg_block(reg_sinkstart) <= sreg_block(reg_sinkstart) + (sdrain_burstcount&"00");

                                                        sburstcount_sink <= sdrain_burstcount-1;

                                                else

                                                        --! Flow Control: Son muy pocos los datos que hay en el buffer de salida y existen aun datos transitando en el resto del pipe ir al estado SOURCE.

                                                        if sZeroTransit='1' then

                                                                --! Flow Control: Finalizada la instrucción, generar una interrupción e ir al estado IDLE.

                                                                sm <= IDLE;

                                                                sreg_block(reg_ctrl)(reg_ctrl_irq) <= '1';

                                                                sreg_block(reg_ctrl)(reg_ctrl_rom) <= '0';

                                                                sreg_block(reg_ctrl)(reg_ctrl_flags_dc downto reg_ctrl_flags_fc) <= sdrain_condition & sflood_condition;

                                                                sreg_block(reg_ctrl)(reg_ctrl_flags_ap downto reg_ctrl_flags_wp) <= sload_add_pending & sfetch_data_pending & sparamload_pending & spipeline_pending & swrite_pending;

                                                        else

                                                                --! Flow Control: Cambiar a Source porque aun hay elementos transitando.

                                                                sm <= SOURCE;

                                                        end if;

                                                end if;

                                        else --!smaster_write=1 

                                                if master_waitrequest = '0' then

                                                        --! Descartar datos : revisar antes de este proceso secuencial la parte combinatoria (Data Dumpster).

                                                        if sburstcount_sink/=zero(mb downto 0) then

                                                                --! Datos pendientes por transmitir aun en el burst. Restar uno 

                                                                sburstcount_sink <= sburstcount_sink-1;

                                                        else

                                                                --! No escribir mas. Finalizar la transmisión

                                                                smaster_write <= '0';

                                                                --! Si no hay transito de dato se con terminada la instrucción siempre que el estado de control de flujo esté sidera  

                                                                if sZeroTransit='1' then

                                                                        --! Flow Control: Finalizada la instrucción, generar una interrupción e ir al estado IDLE.

                                                                        sm <= IDLE;

                                                                        sreg_block(reg_ctrl)(reg_ctrl_irq) <= '1';

                                                                        sreg_block(reg_ctrl)(reg_ctrl_rom) <= '0';

                                                                        sreg_block(reg_ctrl)(reg_ctrl_flags_dc downto reg_ctrl_flags_fc) <= sdrain_condition & sflood_condition;

                                                                        sreg_block(reg_ctrl)(reg_ctrl_flags_ap downto reg_ctrl_flags_wp) <= sload_add_pending & sfetch_data_pending & sparamload_pending & spipeline_pending & swrite_pending;

                                                                end if;

                                                        end if;

                                                end if;

                                        end if;

                                when IDLE =>

                                        --! ******************************************************************************************************************************************************                                              

                                        --! Programming the pipeline

                                        --! ******************************************************************************************************************************************************                                              

                                        --! El registro de control en sus campos fetch e irq, es escribile solo cuando estamos en estado IDLE.           

                                        if sslave_write='1' then

                                                case sslave_address is

                                                        when x"0" =>

                                                                --! Solo se permitira escribir en el registro de control si no hay una interrupción activa o si la hay solamente si se esta intentando desactivar la interrupci´n 

                                                                if sreg_block(reg_ctrl)(reg_ctrl_irq)='0' or sslave_writedata(reg_ctrl_irq)='0' then

                                                                        sreg_block(reg_ctrl)(reg_ctrl_irq downto reg_ctrl_nfetch_low) <= sslave_writedata(reg_ctrl_irq downto reg_ctrl_nfetch_low);

                                                                        sreg_block(reg_ctrl)(reg_ctrl_flags_wp-1 downto reg_ctrl_cmb) <= sslave_writedata(reg_ctrl_flags_wp-1 downto reg_ctrl_cmb);

                                                                        sreg_block(reg_ctrl)(reg_ctrl_rlsc) <= sslave_writedata(reg_ctrl_rlsc);

                                                                        sreg_block(reg_ctrl)(reg_ctrl_ageb downto reg_ctrl_alb) <=sslave_writedata(reg_ctrl_ageb downto reg_ctrl_alb);

                                                                end if;

                                                        when x"6" => sreg_block(reg_outputcounter) <= sslave_writedata;

                                                        when x"7" => sreg_block(reg_inputcounter) <= sslave_writedata;

                                                        when x"8" => sreg_block(reg_fetchstart) <= sslave_writedata;

                                                        when x"9" => sreg_block(reg_sinkstart) <= sslave_writedata;

                                                        when others => null;

                                                end case;

                                        else

                                                if sZeroTransit='0' then

                                                        --! Flow Control: Existe un número de descargas programadas por el sistema, comenzar a realizarlas.

                                                        --! Ir al estado Source.

                                                        sm <= SOURCE;

                                                        sreg_block(reg_ctrl)(reg_ctrl_rom) <= '1';

                                                else

                                                        sreg_block(reg_ctrl)(reg_ctrl_rom) <= '0';

                                                end if;

                                        end if;

                        end case;

                end if;

        end process;

--! ******************************************************************************************************************************************************                                              

--! FLOW CONTROL RTL CODE

--! ******************************************************************************************************************************************************                                              

--! buffer de salida

--! ******************************************************************************************************************************************************                                              

        output_buffer:scfifo

        generic map (almost_empty_value => 2**mb,almost_full_value => (2**fd)-52, lpm_widthu => fd, lpm_numwords => 2**fd, lpm_showahead => "ON", lpm_width => 32, overflow_checking => "ON", underflow_checking => "ON", use_eab => "ON")

        port map        (empty => soutb_e, aclr => '0', clock => clk, rdreq      => soutb_ack, wrreq     => soutb_w,     q => master_writedata, usedw    => soutb_usedw, almost_full => soutb_af, almost_empty => soutb_ae, data => soutb_d);

--! ******************************************************************************************************************************************************                                              

--! PROCESO DE CONTROL DE FLUJO ENTRE EL BUFFER DE RESULTADOS Y EL BUFFER DE SALIDA

--! ******************************************************************************************************************************************************                                              

        FLOW_CONTROL_OUTPUT_STAGE:

        process (clk,rst,master_readdata, master_readdatavalid,sr_e,sreg_block(reg_ctrl)(reg_ctrl_vt downto reg_ctrl_sc),sm,supload_chain,zero,ssync_chain_pending,supload_start)

        begin

                --! Compute initial State.

                --! Escribir en el output buffer.

                if supload_chain=DMA then

                        --! Modo DMA escribir los datos de entrada directamente en el buffer.

                        soutb_w <= master_readdatavalid;

                else

                        --!Modo Arithmetic Pipeline 

                        soutb_w <= not(sr_e);

                end if;

                --! Control de lectura de la cola de resultados.

                if sr_e='0' then

                        --!Hay datos en la cola de resultados.

                        if (supload_chain=UPVZ and sreg_block(reg_ctrl)(reg_ctrl_sc)='0') or supload_chain=SC then

                                --!Se transfiere el ultimo componente vectorial y no se estan cargando resultados escalares.

                                sr_ack <= '1';

                        else

                                sr_ack <= '0';

                        end if;

                else

                        sr_ack <= '0';

                end if;

                --! Decodificar que salida de la cola de resultados se conecta a la entrada del otput buffer

                --! DMA Path Control: Si se encuentra habilitado el modo dma entonces conectar la entrada del buffer de salida a la interconexión

                case supload_chain is

                        when UPVX =>

                                soutb_d <= svx;

                        when UPVY =>

                                soutb_d <= svy;

                        when UPVZ =>

                                soutb_d <= svz;

                        when SC =>

                                soutb_d <= ssc;

                        when DMA =>

                                soutb_d <= master_readdata;

                end case;

                case sreg_block(reg_ctrl)(reg_ctrl_vt downto reg_ctrl_sc) is

                        when "01" =>

                                supload_start <= SC;

                        when others =>

                                supload_start <= UPVX;

                end case;

                --! Máquina de estados para el width adaptation RES(128) -> OUTPUTBUFFER(32).    

                if rst=rstMasterValue then

                        supload_chain <= UPVX;

                elsif clk'event and clk='1' and sreg_block(reg_ctrl)(reg_ctrl_dma)='0' then

                        --! Modo de operación normal.

                        case supload_chain is

                                when UPVX =>

                                        if sr_e='1' then

                                                supload_chain <= supload_start;

                                        else

                                                supload_chain <= UPVY;

                                        end if;

                                when UPVY =>

                                        supload_chain <= UPVZ;

                                when UPVZ =>

                                        if sreg_block(reg_ctrl)(reg_ctrl_sc)='0' then

                                                supload_chain <= UPVX;

                                        else

                                                supload_chain <= SC;

                                        end if;

                                when SC|DMA =>

                                        supload_chain <= supload_start;

                        end case;

                elsif clk'event and clk='1' then

                        --! Modo DMA

                        supload_chain <= DMA;

                end if;

        end process;

--! ******************************************************************************************************************************************************                                              

--! PROCESO DE CONTROL DE FLUJO ENTRE LA ENTRADA DESDE LA INTERCONEXIÓN Y LOS PARAMETROS DE ENTRADA EN EL PIPELINE ARITMETICO

--! ******************************************************************************************************************************************************                                              

        FLOW_CONTROL_INPUT_STAGE:

        process(clk,rst,master_readdatavalid,master_readdata,sreg_block(reg_ctrl)(reg_ctrl_dma downto reg_ctrl_s),sslave_write,sslave_address,supload_chain)

        begin

                --! Está ocurriendo un evento de transición del estado TX al estado FETCH: Programar el enganche de parámetros que vienen de la interconexión.

                --! Mirar como es la carga inicial. Si es Normalizacion o Magnitud (dcs=110) entonces cargar DWAXBX de lo contrario solo DWAX.

                case sreg_block(reg_ctrl)(reg_ctrl_d downto reg_ctrl_s) is

                        when "110"      =>      sdownload_start <= DWAXBX;

                        when others     =>      sdownload_start <= DWAX;

                end case;

                if rst=rstMasterValue then

                        ssync_chain_1 <= '0';

                        sdownload_chain <= DWAX;

                        for i in reg_bz downto reg_ax loop

                                sreg_block(i) <= (others => '0');

                        end loop;

                elsif clk'event and clk='1' then

                        ssync_chain_1   <= '0';

                        if master_readdatavalid='1' and sreg_block(reg_ctrl)(reg_ctrl_dma)='0' then

                                --! El dato en la interconexión es valido, se debe enganchar. 

                                case sdownload_chain is

                                        when DWAX | DWAXBX  =>

                                                --! Cargar el operando correspondiente al componente "X" del vector "A" 

                                                ssync_chain_1 <= '0';

                                                sreg_block(reg_ax) <= master_readdata;

                                                if sdownload_start = DWAXBX then

                                                        --! Operación Unaria por ejemplo magnitud de un vector

                                                        --! Escribir en el registro bx adicionalmente. 

                                                        sreg_block(reg_bx) <= master_readdata;

                                                        --! El siguiente estado es cargar el componente "Y" de del operando a ejecutar.