Subversion Repositories rsa_512

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-- Company: 

-- Engineer: 

-- 

-- Create Date:    20:03:35 11/02/2009 

-- Design Name: 

-- Module Name:    etapas - Behavioral 

-- Project Name: 

-- Target Devices: 

-- Tool versions: 

-- Description: 

--

-- Dependencies: 

--

-- Revision: 

-- Revision 0.01 - File Created

-- Additional Comments: 

--

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library IEEE;

use IEEE.STD_LOGIC_1164.all;

use IEEE.STD_LOGIC_ARITH.all;

use IEEE.STD_LOGIC_UNSIGNED.all;

---- Uncomment the following library declaration if instantiating

---- any Xilinx primitives in this code.

--library UNISIM;

--use UNISIM.VComponents.all;

entity montgomery_mult is

  port(

    clk       : in  std_logic;

    reset     : in  std_logic;

    valid_in  : in  std_logic;

    a         : in  std_logic_vector(15 downto 0);

    b         : in  std_logic_vector(15 downto 0);

    n         : in  std_logic_vector(15 downto 0);

    s_prev    : in  std_logic_vector(15 downto 0);

    n_c       : in  std_logic_vector(15 downto 0);

    s         : out std_logic_vector( 15 downto 0);

    valid_out : out std_logic           -- es le valid out TODO : cambiar nombre

    );

end montgomery_mult;

architecture Behavioral of montgomery_mult is

  component montgomery_step is

                               port(

                                 clk       : in  std_logic;

                                 reset     : in  std_logic;

                                 valid_in  : in  std_logic;

                                 a         : in  std_logic_vector(15 downto 0);

                                 b         : in  std_logic_vector(15 downto 0);

                                 n         : in  std_logic_vector(15 downto 0);

                                 s_prev    : in  std_logic_vector(15 downto 0);

                                 n_c       : in  std_logic_vector(15 downto 0);

                                 s         : out std_logic_vector( 15 downto 0);

                                 valid_out : out std_logic;  -- es le valid out TODO : cambiar nombre

                                 busy      : out std_logic;

                                 b_req     : out std_logic;

                                 a_out     : out std_logic_vector(15 downto 0);

                                 n_out     : out std_logic_vector(15 downto 0);  --seńal que indica que el modulo está ocupado y no puede procesar nuevas peticiones

                                 c_step    : out std_logic;  --genera un pulso cuando termina su computo para avisar al modulo superior

                                 stop      : in  std_logic

                                 );

  end component;

  component fifo_512_bram

    port (

      clk   : in  std_logic;

      rst   : in  std_logic;

      din   : in  std_logic_vector(15 downto 0);

      wr_en : in  std_logic;

      rd_en : in  std_logic;

      dout  : out std_logic_vector(15 downto 0);

      full  : out std_logic;

      empty : out std_logic);

  end component;

  component fifo_256_feedback

    port (

      clk   : in  std_logic;

      rst   : in  std_logic;

      din   : in  std_logic_vector(48 downto 0);

      wr_en : in  std_logic;

      rd_en : in  std_logic;

      dout  : out std_logic_vector(48 downto 0);

      full  : out std_logic;

      empty : out std_logic);

  end component;

  type arr_dat_out is array(0 to 7) of std_logic_vector(15 downto 0);

  type arr_val is array(0 to 7) of std_logic;

  type arr_b is array(0 to 7) of std_logic_vector(15 downto 0);

  signal b_reg, next_b_reg                                              : arr_b;

  signal valid_mid, fifo_reqs, fifo_reqs_reg, next_fifo_reqs_reg, stops : arr_val;

  signal a_out_mid, n_out_mid, s_out_mid                                : arr_dat_out;  --std_logic_vector(15 downto 0);

  --Seńales a la fifo

  signal wr_en, rd_en, empty : std_logic;

  signal fifo_out            : std_logic_vector(15 downto 0);

  signal fifo_out_feedback, fifo_in_feedback : std_logic_vector(48 downto 0);

  signal read_fifo_feedback, empty_feedback  : std_logic;

  --Seńales de entrada al primer PE

  signal a_in, s_in, n_in : std_logic_vector(15 downto 0);

  signal f_valid, busy_pe : std_logic;

  --salida c_step del primer PE para ir contando y saber cuando sacar el valor correcto.

  signal c_step, reg_c_step : std_logic;

  --contador para saber cuando cońo acabamos :)

  signal count, next_count : std_logic_vector(7 downto 0);

  --seńal para escribir el loopback en la fifo de entrada de feedback

  signal wr_fifofeed : std_logic;

  type state_type is (wait_start, process_data, dump_feed);

  signal state, next_state                   : state_type;

  signal reg_busy                            : std_logic;

  signal reset_fifos                         : std_logic;

  signal count_feedback, next_count_feedback : std_logic_vector(15 downto 0);

begin

--Fifo para almacenar b

  fifo_b : fifo_512_bram port map (

    clk   => clk,

    rst   => reset_fifos,

    din   => b,

    wr_en => wr_en,

    rd_en => rd_en,

    dout  => fifo_out,

    empty => empty

    );

--Fifo para el feedback al primer PE

  fifo_feed : fifo_256_feedback port map (

    clk   => clk,

    rst   => reset_fifos,

    din   => fifo_in_feedback,

    wr_en => wr_fifofeed,

    rd_en => read_fifo_feedback,

    dout  => fifo_out_feedback,

    empty => empty_feedback

    );

--Primer PE

  et_first : montgomery_step port map(

    clk       => clk,

    reset     => reset,

    valid_in  => f_valid,

    a         => a_in,

    b         => b_reg(0),

    n         => n_in,

    s_prev    => s_in,

    n_c       => n_c,

    s         => s_out_mid(0),

    valid_out => valid_mid(0),

    busy      => busy_pe,

    b_req     => fifo_reqs(0),

    a_out     => a_out_mid(0),

    n_out     => n_out_mid(0),

    c_step    => c_step,

    stop      => stops(0)

    );

--Ultimo PE

  et_last : montgomery_step port map(

    clk       => clk,

    reset     => reset,

    valid_in  => valid_mid(6),

    a         => a_out_mid(6),

    b         => b_reg(7),

    n         => n_out_mid(6),

    s_prev    => s_out_mid(6),

    n_c       => n_c,

    s         => s_out_mid(7),

    valid_out => valid_mid(7),

    b_req     => fifo_reqs(7),

    a_out     => a_out_mid(7),

    n_out     => n_out_mid(7),

    stop      => stops(7)

    );

  g1     : for i in 1 to 6 generate

    et_i : montgomery_step port map(

      clk       => clk,

      reset     => reset,

      valid_in  => valid_mid(i-1),

      a         => a_out_mid(i-1),

      b         => b_reg(i),

      n         => n_out_mid(i-1),

      s_prev    => s_out_mid(i-1),

      n_c       => n_c,

      s         => s_out_mid(i),

      valid_out => valid_mid(i),

      b_req     => fifo_reqs(i),

      a_out     => a_out_mid(i),

      n_out     => n_out_mid(i),

      stop      => stops(i)

      );

  end generate g1;

  process(clk, reset)

  begin

    if(clk = '1' and clk'event) then

      if(reset = '1')then

        state               <= wait_start;

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

        reg_busy            <= '0';

        for i in 0 to 7 loop

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

          fifo_reqs_reg (i) <= '0';

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

          reg_c_step        <= '0';

        end loop;

      else

        state               <= next_state;

        reg_busy            <= busy_pe;

        count_feedback      <= next_count_feedback;

        for i in 0 to 7 loop

          b_reg(i)          <= next_b_reg(i);

          fifo_reqs_reg (i) <= next_fifo_reqs_reg(i);

          count             <= next_count;

          reg_c_step        <= c_step;

        end loop;

      end if;

    end if;

  end process;

  --Proceso combinacional que controla las lecturas a la fifo

  process(fifo_reqs_reg, fifo_out, b, fifo_reqs, b_reg, state, empty)

  begin

    for i in 0 to 7 loop

      next_b_reg(i)         <= b_reg(i);

      next_fifo_reqs_reg(i) <= fifo_reqs(i);

    end loop;

    if(state = wait_start) then

      next_b_reg(0)           <= b;

      next_fifo_reqs_reg(0)   <= '0';   --anulamos la peticion de b

      for i in 1 to 7 loop

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

        next_fifo_reqs_reg(i) <= '0';

      end loop;

    else

      for i in 0 to 7 loop

        if(fifo_reqs_reg(i) = '1' and empty = '0') then

          next_b_reg(i)       <= fifo_out;

        end if;

      end loop;

    end if;

  end process;

  --Proceso combinacional fsm principal

  process( valid_in, b, state, fifo_reqs, a_out_mid, n_out_mid, s_out_mid, valid_mid, a, s_prev, n, busy_pe, empty_feedback, fifo_out_feedback, count, reg_c_step, reset, reg_busy, count_feedback )

  begin

    --las peticiones a la fifo son las or de los modulos

    rd_en              <= fifo_reqs(0) or fifo_reqs(1) or fifo_reqs(2) or fifo_reqs(3) or fifo_reqs(4) or fifo_reqs(5) or fifo_reqs(6) or fifo_reqs(7);

    next_state         <= state;

    wr_en              <= '0';

    fifo_in_feedback   <= a_out_mid(7)&n_out_mid(7)&s_out_mid(7)&valid_mid(7);

    read_fifo_feedback <= '0';

    wr_fifofeed        <= '0';

    --Controlamos el primer PE

    a_in               <= a;

    s_in               <= s_prev;

    n_in               <= n;

    f_valid            <= valid_in;

    reset_fifos        <= reset;

    --ponemos las salidas

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

    valid_out          <= '0';

    --Incrementamos el contador solo cuando el primer PE termina su cuenta

    next_count          <= count;

    next_count_feedback <= count_feedback;

    --El contador solo se incrementa una vez por ciclo de la pipeline, así me evito que cada PE lo incremente

    if(reg_c_step = '1') then

      next_count        <= count + 8;

    end if;

    --durante el ciclo de la pipeline que sea considerado el ultimo, sacamos los datos

    if( count = x"20") then

      s                 <= s_out_mid(0);

      valid_out         <= valid_mid(0);

    end if;

    for i in 0 to 7 loop

      stops(i) <= '0';

    end loop;

    case state is

      --Esperamos a que tengamos un input y vamos cargando las b's

      when wait_start =>

        reset_fifos   <= '1';

        if(valid_in = '1') then

          reset_fifos <= '0';

          --next_b_reg(0) <= b;

          next_state  <= process_data;

                                        --wr_en <= '1';

        end if;

      when process_data =>

        wr_fifofeed <= valid_mid(7);

        if(valid_in = '1') then

          wr_en     <= '1';

        end if;

        --Miramos si hay que volver a meter datos a la b

        if(empty_feedback = '0' and reg_busy = '0') then

          read_fifo_feedback <= '1';

          next_state <= dump_feed;

          next_count_feedback <= x"0000";

        end if;

        --Si ya hemos sobrepasado el limite paramos y volvemos a la espera

        if( count >  x"23") then

          next_state <= wait_start;

                                        --y

          for i in 0 to 7 loop

            stops(i) <= '1';

          end loop;

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

        end if;

        --Vacia la fifo de feedback

      when dump_feed =>

        if(empty_feedback='0')

        then

          next_count_feedback <= count_feedback+1;

        end if;

        wr_fifofeed <= valid_mid(7);

        read_fifo_feedback <= '1';

        a_in <= fifo_out_feedback(48 downto 33);

        n_in <= fifo_out_feedback(32 downto 17);

        s_in <= fifo_out_feedback(16 downto 1);

        f_valid <= fifo_out_feedback(0);

        if(empty_feedback='1') then

          next_state <= process_data;

        end if;

        if(count_feedback = x"22") then

          read_fifo_feedback <= '0';

          next_state <= process_data;

        end if;

    end case;

  end process;

end Behavioral;