Subversion Repositories nanoblaze

--##############################################################################

--

--  nanoblaze

--      Top view of the NanoBlaze processor

--

--      The processor is compatible with the Xilinx PicoBlaze

--      <http://www.picoblaze.info>, but different bit widths can be adapted

--      in order to have a larger processor.

--

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

--

--  Versions / Authors

--      1.0 Francois Corthay    first implementation

--

--  Provided under GNU LGPL licence: <http://www.gnu.org/copyleft/lesser.html>

--

--  by the electronics group of "HES-SO//Valais Wallis", in Switzerland:

--  <http://www.hevs.ch/en/rad-instituts/institut-systemes-industriels/>.

--

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--

--  Usage

--      Set the proper values for all generics.

--

--      Edit an assembler file and compile it as the architecture of "programRom".

--

--      The "reset" signal is active high.

--

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--

--  Synthesis results

--      A circuit compatible with the PicoBlaze sizes gives the following

--      synthesis result on a Xilinx Spartan3-1000:

--          Number of Slice Flip Flops:           157 out of  15,360    1%

--          Number of 4 input LUTs:               446 out of  15,360    2%

--          Number of BRAMs:                        1 out of      24    4%

--

--##############################################################################

LIBRARY ieee;

  USE ieee.std_logic_1164.all;

  USE ieee.numeric_std.all;

ENTITY nanoBlaze IS

  GENERIC(

    addressBitNb           : positive := 8;

    registerBitNb          : positive := 8;

    programCounterBitNb    : positive := 10;

    stackPointerBitNb      : positive := 5;

    registerAddressBitNb   : positive := 4;

    scratchpadAddressBitNb : natural  := 6

  );

  PORT(

    reset       : IN     std_ulogic;

    clock       : IN     std_ulogic;

    en          : IN     std_ulogic;

    dataAddress : OUT    unsigned(addressBitNb-1 DOWNTO 0);

    dataOut     : OUT    std_ulogic_vector(registerBitNb-1 DOWNTO 0);

    dataIn      : IN     std_ulogic_vector(registerBitNb-1 DOWNTO 0);

    readStrobe  : OUT    std_uLogic;

    writeStrobe : OUT    std_uLogic;

    int         : IN     std_uLogic;

    intAck      : OUT    std_ulogic

  );

END nanoBlaze ;

--==============================================================================

ARCHITECTURE struct OF nanoBlaze IS

  constant instructionBitNb: positive := 18;

  SIGNAL instruction    : std_ulogic_vector(instructionBitNb-1 DOWNTO 0);

  SIGNAL logic1         : std_ulogic;

  SIGNAL programCounter : unsigned(programCounterBitNb-1 DOWNTO 0);

  COMPONENT nanoProcessor

    GENERIC (

      addressBitNb           : positive := 8;

      registerBitNb          : positive := 8;

      registerAddressBitNb   : positive := 4;

      programCounterBitNb    : positive := 10;

      stackPointerBitNb      : positive := 5;

      instructionBitNb       : positive := 18;

      scratchpadAddressBitNb : natural  := 4

    );

    PORT (

      reset       : IN  std_uLogic;

      clock       : IN  std_uLogic;

      en          : IN  std_uLogic;

      progCounter : OUT unsigned(programCounterBitNb-1 DOWNTO 0);

      instruction : IN  std_ulogic_vector(instructionBitNb-1 DOWNTO 0);

      dataAddress : OUT unsigned(addressBitNb-1 DOWNTO 0);

      dataOut     : OUT std_ulogic_vector(registerBitNb-1 DOWNTO 0);

      dataIn      : IN  std_ulogic_vector(registerBitNb-1 DOWNTO 0);

      readStrobe  : OUT std_uLogic;

      writeStrobe : OUT std_uLogic;

      int         : IN  std_uLogic;

      intAck      : OUT std_ulogic

    );

  END COMPONENT;

  COMPONENT programRom

    GENERIC (

      addressBitNb : positive := 8;

      dataBitNb    : positive := 8

    );

    PORT (

      reset   : IN  std_uLogic;

      clock   : IN  std_uLogic;

      en      : IN  std_uLogic;

      address : IN  unsigned(addressBitNb-1 DOWNTO 0);

      dataOut : OUT std_ulogic_vector(dataBitNb-1 DOWNTO 0)

    );

  END COMPONENT;

BEGIN

  logic1 <= '1';

  I_up : nanoProcessor

    GENERIC MAP (

      addressBitNb           => addressBitNb,

      registerBitNb          => registerBitNb,

      registerAddressBitNb   => registerAddressBitNb,

      programCounterBitNb    => programCounterBitNb,

      stackPointerBitNb      => stackPointerBitNb,

      instructionBitNb       => instructionBitNb,

      scratchpadAddressBitNb => scratchpadAddressBitNb

    )

    PORT MAP (

      reset       => reset,

      clock       => clock,

      en          => en,

      progCounter => programCounter,

      instruction => instruction,

      dataAddress => dataAddress,

      dataOut     => dataOut,

      dataIn      => dataIn,

      readStrobe  => readStrobe,

      writeStrobe => writeStrobe,

      int         => int,

      intAck      => intAck

    );

  I_rom : programRom

    GENERIC MAP (

      addressBitNb => programCounterBitNb,

      dataBitNb    => instructionBitNb

    )

    PORT MAP (

      reset   => reset,

      clock   => clock,

      en      => logic1,

      address => programCounter,

      dataOut => instruction

    );

END ARCHITECTURE struct;