Subversion Repositories t48

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

--

-- The testbench for t48_core.

--

-- $Id: tb.vhd,v 1.14 2006-06-21 01:04:05 arniml Exp $

--

-- Copyright (c) 2004, Arnim Laeuger (arniml@opencores.org)

--

-- All rights reserved

--

-- Redistribution and use in source and synthezised forms, with or without

-- modification, are permitted provided that the following conditions are met:

--

-- Redistributions of source code must retain the above copyright notice,

-- this list of conditions and the following disclaimer.

--

-- Redistributions in synthesized form must reproduce the above copyright

-- notice, this list of conditions and the following disclaimer in the

-- documentation and/or other materials provided with the distribution.

--

-- Neither the name of the author nor the names of other contributors may

-- be used to endorse or promote products derived from this software without

-- specific prior written permission.

--

-- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

-- AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,

-- THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

-- PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE

-- LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

-- CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

-- SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

-- INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

-- CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

-- ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

-- POSSIBILITY OF SUCH DAMAGE.

--

-- Please report bugs to the author, but before you do so, please

-- make sure that this is not a derivative work and that

-- you have the latest version of this file.

--

-- The latest version of this file can be found at:

--      http://www.opencores.org/cvsweb.shtml/t48/

--

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

library ieee;

use ieee.std_logic_1164.all;

entity tb is

end tb;

use work.t48_core_comp_pack.all;

use work.t48_tb_pack.all;

architecture behav of tb is

  -- clock period, 11 MHz

  constant period_c : time := 90 ns;

  component if_timing

    port(

      xtal_i   : in std_logic;

      ale_i    : in std_logic;

      psen_n_i : in std_logic;

      rd_n_i   : in std_logic;

      wr_n_i   : in std_logic;

      prog_n_i : in std_logic;

      db_bus_i : in std_logic_vector(7 downto 0);

      p2_i     : in std_logic_vector(7 downto 0)

    );

  end component;

  component lpm_rom

    generic (

      LPM_WIDTH           : positive;

      LPM_TYPE            : string    := "LPM_ROM";

      LPM_WIDTHAD         : positive;

      LPM_NUMWORDS        : natural   := 0;

      LPM_FILE            : string;

      LPM_ADDRESS_CONTROL : string    := "REGISTERED";

      LPM_OUTDATA         : string    := "REGISTERED";

      LPM_HINT            : string    := "UNUSED"

    );

    port (

      address             : in  std_logic_vector(LPM_WIDTHAD-1 downto 0);

      inclock             : in  std_logic;

      outclock            : in  std_logic;

      memenab             : in  std_logic;

      q                   : out std_logic_vector(LPM_WIDTH-1 downto 0)

    );

  end component;

  signal xtal_s          : std_logic;

  signal xtal_n_s        : std_logic;

  signal res_n_s         : std_logic;

  signal xtal3_s         : std_logic;

  signal int_n_s         : std_logic;

  signal ale_s           : std_logic;

  signal rom_addr_s      : std_logic_vector(11 downto 0);

  signal rom_data_s      : std_logic_vector( 7 downto 0);

  signal ram_data_to_s   : std_logic_vector( 7 downto 0);

  signal ram_data_from_s : std_logic_vector( 7 downto 0);

  signal ram_addr_s      : std_logic_vector( 7 downto 0);

  signal ram_we_s        : std_logic;

  signal p1_s            : std_logic_vector( 7 downto 0);

  signal t48_p1_s        : std_logic_vector( 7 downto 0);

  signal p1_low_imp_s    : std_logic;

  signal p2_s            : std_logic_vector( 7 downto 0);

  signal t48_p2_s        : std_logic_vector( 7 downto 0);

  signal p2l_low_imp_s   : std_logic;

  signal p2h_low_imp_s   : std_logic;

  signal psen_n_s        : std_logic;

  signal prog_n_s        : std_logic;

  signal bus_s           : std_logic_vector( 7 downto 0);

  signal t48_bus_s       : std_logic_vector( 7 downto 0);

  signal bus_dir_s       : std_logic;

  signal ext_mem_addr_q      : std_logic_vector( 7 downto 0);

  signal ext_ram_data_from_s : std_logic_vector( 7 downto 0);

  signal ext_ram_we_q        : std_logic;

  signal rd_n_s              : std_logic;

  signal wr_n_s              : std_logic;

  signal ext_rom_data_s  : std_logic_vector( 7 downto 0);

  signal ext_rom_addr_s  : std_logic_vector(11 downto 0);

  signal tb_p1_q : std_logic_vector( 7 downto 0);

  signal tb_p2_q : std_logic_vector( 7 downto 0);

  signal ext_mem_sel_we_q : boolean;

  signal ena_ext_ram_q    : boolean;

  signal ena_tb_periph_q  : boolean;

  signal zero_s          : std_logic;

  signal one_s           : std_logic;

  signal zero_byte_s     : std_logic_vector( 7 downto 0);

begin

  zero_s      <= '0';

  one_s       <= '1';

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

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

  -- Internal ROM, 2k bytes

  -- Initialized by file rom_t49.hex.

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

  rom_internal_2k : lpm_rom

    generic map (

      LPM_WIDTH           => 8,

      LPM_TYPE            => "LPM_ROM",

      LPM_WIDTHAD         => 11,

      LPM_NUMWORDS        => 2 ** 11,

      LPM_FILE            => "rom_t49.hex",

      LPM_ADDRESS_CONTROL => "REGISTERED",

      LPM_OUTDATA         => "UNREGISTERED",

      LPM_HINT            => "UNUSED"

    )

    port map (

      address  => rom_addr_s(10 downto 0),

      inclock  => xtal_s,

      outclock => zero_s,               -- unused

      memenab  => one_s,

      q        => rom_data_s

    );

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

  -- External ROM, 2k bytes

  -- Initialized by file rom_t49_ext.hex.

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

  ext_rom_addr_s(11 downto 8) <= t48_p2_s(3 downto 0);

  ext_rom_addr_s( 7 downto 0) <= ext_mem_addr_q;

  rom_external_2k : lpm_rom

    generic map (

      LPM_WIDTH           => 8,

      LPM_TYPE            => "LPM_ROM",

      LPM_WIDTHAD         => 11,

      LPM_NUMWORDS        => 2 ** 11,

      LPM_FILE            => "rom_t49_ext.hex",

      LPM_ADDRESS_CONTROL => "REGISTERED",

      LPM_OUTDATA         => "UNREGISTERED",

      LPM_HINT            => "UNUSED"

    )

    port map (

      address  => ext_rom_addr_s(10 downto 0),

      inclock  => xtal_s,

      outclock => zero_s,               -- unused

      memenab  => one_s,

      q        => ext_rom_data_s

    );

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

  -- Internal RAM, 256 bytes

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

  ram_256 : generic_ram_ena

    generic map (

      addr_width_g => 8,

      data_width_g => 8

    )

    port map (

      clk_i => xtal_s,

      a_i   => ram_addr_s,

      we_i  => ram_we_s,

      ena_i => one_s,

      d_i   => ram_data_to_s,

      d_o   => ram_data_from_s

    );

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

  -- External RAM, 256 bytes

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

  ext_ram_b : generic_ram_ena

    generic map (

      addr_width_g => 8,

      data_width_g => 8

    )

    port map (

      clk_i => xtal_s,

      a_i   => ext_mem_addr_q,

      we_i  => ext_ram_we_q,

      ena_i => one_s,

      d_i   => bus_s,

      d_o   => ext_ram_data_from_s

    );

  t48_core_b : t48_core

    generic map (

      xtal_div_3_g        => 1,

      register_mnemonic_g => 1,

      include_port1_g     => 1,

      include_port2_g     => 1,

      include_bus_g       => 1,

      include_timer_g     => 1,

      sample_t1_state_g   => 4

    )

    port map (

      xtal_i        => xtal_s,

      xtal_en_i     => one_s,

      reset_i       => res_n_s,

      t0_i          => p1_s(0),

      t0_o          => open,

      t0_dir_o      => open,

      int_n_i       => int_n_s,

      ea_i          => rom_addr_s(11),

      rd_n_o        => rd_n_s,

      psen_n_o      => psen_n_s,

      wr_n_o        => wr_n_s,

      ale_o         => ale_s,

      db_i          => bus_s,

      db_o          => t48_bus_s,

      db_dir_o      => bus_dir_s,

      t1_i          => p1_s(1),

      p2_i          => p2_s,

      p2_o          => t48_p2_s,

      p2l_low_imp_o => p2l_low_imp_s,

      p2h_low_imp_o => p2h_low_imp_s,

      p1_i          => p1_s,

      p1_o          => t48_p1_s,

      p1_low_imp_o  => p1_low_imp_s,

      prog_n_o      => prog_n_s,

      clk_i         => xtal_s,

      en_clk_i      => xtal3_s,

      xtal3_o       => xtal3_s,

      dmem_addr_o   => ram_addr_s,

      dmem_we_o     => ram_we_s,

      dmem_data_i   => ram_data_from_s,

      dmem_data_o   => ram_data_to_s,

      pmem_addr_o   => rom_addr_s,

      pmem_data_i   => rom_data_s

    );

  if_timing_b : if_timing

    port map (

      xtal_i   => xtal_s,

      ale_i    => ale_s,

      psen_n_i => psen_n_s,

      rd_n_i   => rd_n_s,

      wr_n_i   => wr_n_s,

      prog_n_i => prog_n_s,

      db_bus_i => bus_s,

      p2_i     => t48_p2_s

    );

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

  -- Port logic

  --

  ports: process (t48_p1_s,

                  p1_low_imp_s,

                  t48_p2_s,

                  p2l_low_imp_s,

                  p2h_low_imp_s)

    function t48_port_f(t48_p   : std_logic_vector;

                        low_imp : std_logic) return std_logic_vector is

      variable p_v : std_logic_vector(t48_p'range);

    begin

      if low_imp = '1' then

        p_v := t48_p;

      else

        for i in p_v'range loop

          if t48_p(i) = '1' then

            p_v(i) := 'H';

          else

            p_v(i) := t48_p(i);

          end if;

        end loop;

      end if;

      return p_v;

    end;

  begin

    p1_s <= t48_port_f(t48_p   => t48_p1_s,

                       low_imp => p1_low_imp_s);

    p2_s(3 downto 0) <= t48_port_f(t48_p   => t48_p2_s(3 downto 0),

                                   low_imp => p2l_low_imp_s);

    p2_s(7 downto 4) <= t48_port_f(t48_p   => t48_p2_s(7 downto 4),

                                   low_imp => p2h_low_imp_s);

  end process ports;

  --

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

  bus_s <=   t48_bus_s

           when bus_dir_s = '1' else

             (others => 'Z');

  bus_s <=   ext_ram_data_from_s

           when rd_n_s = '0' and ena_ext_ram_q else

             (others => 'Z');

  bus_s <=   ext_rom_data_s

           when psen_n_s = '0' else

             (others => 'Z');

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

  -- External memory access signals

  --

  ext_mem: process (wr_n_s,

                    ext_mem_addr_q,

                    ena_ext_ram_q,

                    ale_s,

                    bus_s,

                    xtal_s)

  begin

    if ale_s'event and ale_s = '0' then

      if not is_X(bus_s) then

        ext_mem_addr_q <= bus_s;

      else

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

      end if;

    end if;

    if wr_n_s'event and wr_n_s = '1' then

      -- write enable for external RAM

      if ena_ext_ram_q then

        ext_ram_we_q <= '1';

      end if;

      -- process external memory selector

      if ext_mem_addr_q = "11111111" then

        ext_mem_sel_we_q <= true;

      end if;

    end if;

    if xtal_s'event and xtal_s = '1' then

      ext_ram_we_q     <= '0';

      ext_mem_sel_we_q <= false;

    end if;

  end process ext_mem;

  --

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

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

  -- Process ext_mem_sel

  --

  -- Purpose:

  --   Select external memory address space.

  --   This is either

  --     + external RAM

  --     + testbench peripherals

  --

  ext_mem_sel: process (res_n_s, xtal_s)

  begin

    if res_n_s = '0' then

      ena_ext_ram_q       <= true;

      ena_tb_periph_q     <= false;

    elsif xtal_s'event and xtal_s = '1' then

      if ext_mem_sel_we_q then

        if bus_s(0) = '1' then

          ena_ext_ram_q   <= true;

        else

          ena_ext_ram_q   <= false;

        end if;

        if bus_s(1) = '1' then

          ena_tb_periph_q <= true;

        else

          ena_tb_periph_q <= false;

        end if;

      end if;

    end if;

  end process ext_mem_sel;

  --

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

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

  -- Process tb_periph

  --

  -- Purpose:

  --   Implements the testbenc peripherals driving P1 and P2.

  --

  tb_periph: process (res_n_s, wr_n_s)

    function oc_f (pX : std_logic_vector) return std_logic_vector is

      variable r_v : std_logic_vector(pX'range);

    begin

      for i in pX'range loop

        if pX(i) = '0' then

          r_v(i) := '0';

        else

          r_v(i) := 'H';

        end if;

      end loop;

      return r_v;

    end;

  begin

    if res_n_s = '0' then

      tb_p1_q <= (others => 'H');

      tb_p2_q <= (others => 'H');

    elsif wr_n_s'event and wr_n_s = '1' then

      if ena_tb_periph_q then

        case ext_mem_addr_q is

          -- P1

          when "00000000" =>

            tb_p1_q <= oc_f(t48_bus_s);

          -- P2

          when "00000001" =>

            tb_p2_q <= oc_f(t48_bus_s);

          when others =>

            null;

        end case;

      end if;

    end if;

  end process tb_periph;

  --

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

  p1_s <= tb_p1_q;

  p2_s <= tb_p2_q;

  xtal_n_s <= not xtal_s;

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

  -- The clock generator

  --

  clk_gen: process

  begin

    xtal_s <= '0';

    wait for period_c/2;

    xtal_s <= '1';

    wait for period_c/2;

  end process clk_gen;

  --

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

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

  -- The reset generator

  --

  res_gen: process

  begin

    res_n_s <= '0';

    wait for 5 * period_c;

    res_n_s <= '1';

    wait;

  end process res_gen;

  --

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

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

  -- The interrupt generator

  --

  int_gen: process

  begin

    int_n_s <= '1';

    wait for 750 * period_c;

    int_n_s <= '0';

    wait for  45 * period_c;

  end process int_gen;

  --

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

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

  -- End of simulation detection

  --

  eos: process

  begin

    outer: loop

      wait on tb_accu_s;

      if tb_accu_s = "10101010" then

        wait on tb_accu_s;

        if tb_accu_s = "01010101" then

          wait on tb_accu_s;

          if tb_accu_s = "00000001" then

            -- wait for instruction strobe of this move

            wait until tb_istrobe_s'event and tb_istrobe_s = '1';

            -- wait for next strobe

            wait until tb_istrobe_s'event and tb_istrobe_s = '1';

            assert false

              report "Simulation Result: PASS."

              severity note;

          else

            assert false

              report "Simulation Result: FAIL."

              severity note;

          end if;

          assert false

            report "End of simulation reached."

            severity failure;

        end if;

      end if;

    end loop;

  end process eos;

  --

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

end behav;

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

-- File History:

--

-- $Log: not supported by cvs2svn $

-- Revision 1.13  2006/06/20 00:45:26  arniml

-- new input xtal_en_i

--

-- Revision 1.12  2005/11/01 21:21:48  arniml

-- split low impedance markers for P2

--

-- Revision 1.11  2005/09/07 17:39:40  arniml

-- fix missing assignment to outclock

--

-- Revision 1.10  2004/05/21 11:24:47  arniml

-- split 4k internal ROM into

--   + 2k internal ROM

--   + 2k external ROM

-- EA of t48_core is driven by MSB of internal ROM address

-- if upper 2k block is selected, the system switches to EA mode on the fly

--

-- Revision 1.9  2004/05/17 14:43:33  arniml

-- add testbench peripherals for P1 and P2

-- this became necessary to observe a difference between externally applied

-- port data and internally applied port data

--

-- Revision 1.8  2004/04/25 20:41:48  arniml

-- connect if_timing to P2 output of T48

--

-- Revision 1.7  2004/04/25 16:23:21  arniml

-- added if_timing

--

-- Revision 1.6  2004/04/14 20:57:44  arniml

-- wait for instruction strobe after final end-of-simulation detection

-- this ensures that the last mov instruction is part of the dump and

-- enables 100% matching with i8039 simulator

--

-- Revision 1.5  2004/03/29 19:45:15  arniml

-- rename pX_limp to pX_low_imp

--

-- Revision 1.4  2004/03/28 21:30:25  arniml

-- connect prog_n_o

--

-- Revision 1.3  2004/03/26 22:39:28  arniml

-- enhance simulation result string

--

-- Revision 1.2  2004/03/24 23:22:35  arniml

-- put ext_ram on falling clock edge to sample the write enable properly

--

-- Revision 1.1  2004/03/24 21:42:10  arniml

-- initial check-in

--

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