Subversion Repositories openfpu64

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

-- Project    : openFPU64 - Testbench for Avalon Bus

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

-- File       : openfpu64_tb.vhd

-- Author     : Peter Huewe  <peterhuewe@gmx.de>

-- Created    : 2010-04-19

-- Last update: 2010-04-19

-- Standard   : VHDL'87

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

-- Description: Testbench for openFPU64, Avalon Bus interface.

-- 

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

-- Copyright (c) 2010 

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

-- License: gplv3, see licence.txt

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

library ieee;

use ieee.std_logic_1164.all;

library ieee;

use ieee.std_logic_1164.all;

use ieee.numeric_std.all;

library work;

use work.helpers.all;

use work.fpu_package.all;

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

entity openFPU64_tb is

end openFPU64_tb;

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

architecture openFPU64_tb of openFPU64_tb is

  component openFPU64

    port (

      reset_n       : in  std_logic                     := '0';

      read          : in  std_logic                     := '0';

      write         : in  std_logic                     := '1';

      address       : in  std_logic_vector (4 downto 0) := (others => '0');

      readdata      : out std_logic_vector(31 downto 0) := (others => '0');

      writedata     : in  std_logic_vector(31 downto 0) := (others => '0');

      waitrequest   : out std_logic                     := '0';

      begintransfer : in  std_logic                     := '0';

      --   out_port      : out std_logic_vector(9 downto 0);

      clk           : in  std_logic                     := '0');

  end component;

  -- component ports

  signal reset_n   : std_logic                     := '0';

  signal read      : std_logic                     := '0';

  signal write     : std_logic                     := '1';

  signal address   : std_logic_vector (4 downto 0) := (others => '0');

  signal readdata  : std_logic_vector(31 downto 0) := (others => '0');

  signal writedata : std_logic_vector(31 downto 0) := (others => '0');

--    signal data_in_a : std_logic_vector(63 downto 0) :=  x"AFAFAFAFEFEFEFEF";

--   signal data_in_b : std_logic_vector(63 downto 0) :=  x"BFBFBFBFCFCFCFCF";

  signal data_in_a : std_logic_vector(63 downto 0) := "0011111111110000000000000000000000000000000000000000000000000000";

  signal data_in_b : std_logic_vector(63 downto 0) := "0100000000000000000000000000000000000000000000000000000000000000";

  signal data_out      : std_logic_vector(63 downto 0);

  signal readback      : std_logic_vector(31 downto 0) := (others => '0');

  signal waitrequest   : std_logic                     := '0';

  signal begintransfer : std_logic                     := '0';

  signal clk           : std_logic                     := '0';

  signal out_port      : std_logic_vector(9 downto 0);

  -- clock

  -- signal Clk : std_logic := '1';

  constant clk_period  : time                          := 10 ns;

  constant mem_delay   : time                          := 10 ns;

begin  -- openFPU64_tb

  -- component instantiation

  DUT : openFPU64

    port map (

      reset_n       => reset_n,

      read          => read,

      write         => write,

      address       => address,

      readdata      => readdata,

      writedata     => writedata,

      waitrequest   => waitrequest,

      begintransfer => begintransfer,

      clk           => clk);

  -- clock generation

  -- waveform generation

  tb : process

    procedure run_cycle

      (

        count : inout integer           -- cycle count for statistical purposes

        )

    is

    begin

      clk   <= '0';

      wait for clk_period / 2;

      clk   <= '1';

      wait for clk_period / 2;

      count := count+1;

    end procedure;

  procedure testcase

    (

      number    : in integer;           -- Testcase number, will be reported

      operand_a : in std_logic_vector(63 downto 0);   -- first operand

      operand_b : in std_logic_vector (63 downto 0);  -- second operand

      expected  : in std_logic_vector(63 downto 0);   -- expected result

      operation : in std_logic_vector (2 downto 0)    -- desired operation

      )

  is

    variable i           : integer;

    variable denormalA_n : std_logic;

    variable denormalB_n : std_logic;

  begin

    i :=0;

    -- reset the fpu

    begintransfer <= '0';

    reset_n       <= '0';

    run_cycle(i);

    reset_n       <= '1';

    run_cycle(i);

    -- begin transfer of first 32bit (MSB..) of first operand

    -- and specify operation (encoded in address, see fpu_package.vhd for details

    write         <= '1';

    begintransfer <= '1';

    writedata     <= operand_a(63 downto 32);

    address       <= operation & addr_a_hi;

    run_cycle(i);

    begintransfer <= '0';               --all other signals irrelevant/unstable

    run_cycle(i);

-- begin transfer of second 32bits (..LSB) of first operand

    write         <= '1';

    begintransfer <= '1';

    address       <= operation& addr_a_lo;

    writedata     <= operand_a(31 downto 0);

    run_cycle(i);

    begintransfer <= '0';

    run_cycle(i);

    -- begin transfer of first 32bits (MSB..) of second operand

    write         <= '1';

    address       <= operation& addr_b_hi;

    writedata     <= operand_b(63 downto 32);

    begintransfer <= '1';

    run_cycle(i);

    begintransfer <= '0';

    run_cycle(i);

    -- begin transfer of second 32bits (..LSB) of second operand

    address       <= operation& addr_b_lo;

    writedata     <= operand_b(31 downto 0);

    begintransfer <= '1';

    run_cycle(i);

    begintransfer <= '0';

    write         <= '0';

    run_cycle(i);

-- begin reading first 32bits of result

-- blocking read, all signals have to remain stable until waitrequest is deasserted

    read          <= '1';

    begintransfer <= '1';

    address       <= operation & addr_result_hi;

    run_cycle(i);

    begintransfer <= '0';

    L : while waitrequest = '1' loop

      run_cycle(i);

    end loop;

    data_out(63 downto 32) <= readdata;

    run_cycle(i);

    -- begin reading second 32bits of result

    -- blocking read, all signals have to remain stable until waitrequest is deasserted

    -- in practice waitrequest is already deasserted.

    read          <= '1';

    begintransfer <= '1';

    address       <= operation & addr_result_lo;

    run_cycle(i);

    begintransfer <= '0';

    K :while waitrequest = '1' loop

      run_cycle(i);

    end loop;

    data_out(31 downto 0) <= readdata;

    run_cycle(i);

-- Bus transfers complete

-- compare actual result with expected result

    assert data_out = expected report "doh "&integer'image(number)&" result was"&

      " S:"&std_logic'image(data_out(63)) &

      " E:"&to_string(data_out(62 downto 52)) &

      " M:"&to_string(data_out(51 downto 0)) &

      " expected" &

      " S:"&std_logic'image(expected(63)) &

      " E:"&to_string(expected(62 downto 52)) &

      " M:"&to_string(expected(51 downto 0)) severity error;

-- print out statistics

    assert false report "Testcases "&integer'image(number)&" needed " &integer'image(i) &" cycles" severity note;

  end procedure;

  variable i : integer;

  begin