Subversion Repositories System09

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

--

--  S Y N T H E Z I A B L E    System09 - SOC.

--

--  www.OpenCores.Org - September 2003

--  This core adheres to the GNU public license  

--

-- File name      : System09.vhd

--

-- Purpose        : Top level file for 6809 compatible system on a chip

--                  Designed with Xilinx XC2S300e Spartan 2+ FPGA.

--                  Implemented With BurchED B5-X300 FPGA board,

--                  B5-SRAM module, B5-CF module and B5-FPGA-CPU-IO module

--

-- Dependencies   : ieee.Std_Logic_1164

--                  ieee.std_logic_unsigned

--                  ieee.std_logic_arith

--                  ieee.numeric_std

--

-- Uses           : 

--                  cpu09      (cpu09.vhd)      CPU core

--                  mon_rom    (sys09bug_rom2k_b4.vhd) Monitor ROM

--                  dat_ram    (datram.vhd)     Dynamic Address Translation

--                  acia_6850  (ACIA_6850.vhd) ACIA / MiniUART

--                             (ACIA_RX.vhd)

--                             (ACIA_TX.vhd)

--                  ACIA_Clock (ACIA_Clock.vhd) ACIA Baud Clock Divider

--                  keyboard   (keyboard.vhd)   PS/2 Keyboard Interface

--                  vdu8       (vdu8.vhd)       80 x 25 Video Display

--                  timer      (timer.vhd)      Timer module

--                  trap            (trap.vhd)       Bus Trap interrupt

--                  ioport     (ioport.vhd)     Parallel I/O port.

-- 

-- Author         : John E. Kent      

--                  dilbert57@opencores.org      

--      Memory Map     :

-- $E000 - ACIA (SWTPc)

-- $E010 - Reserved for FD1771 FDC (SWTPc)

-- $E020 - Keyboard

-- $E030 - VDU

-- $E040 - Compact Flash

-- $E050 - Timer

-- $E060 - Bus trap

-- $E070 - Parallel I/O

-- $E080 - Reserved for 6821 PIA (?) (SWTPc)

-- $E090 - Reserved for 6840 PTM (?) (SWTPc)

--

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

--

-- Revision History:

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

-- Version 0.1 - 20 March 2003

-- Version 0.2 - 30 March 2003

-- Version 0.3 - 29 April 2003

-- Version 0.4 - 29 June 2003

--

-- Version 0.5 - 19 July 2003

-- prints out "Hello World"

--

-- Version 0.6 - 5 September 2003

-- Runs SBUG

--

-- Version 1.0- 6 Sep 2003 - John Kent

-- Inverted SysClk

-- Initial release to Open Cores

--

-- Version 1.1 - 17 Jan 2004 - John Kent

-- Updated miniUart.

--

-- Version 1.2 - 25 Jan 2004 - John Kent

-- removed signals "test_alu" and "test_cc" 

-- Trap hardware re-instated.

--

-- Version 1.3 - 11 Feb 2004 - John Kent

-- Designed forked off to produce System09_VDU

-- Added VDU component

--      VDU runs at 25MHz and divides the clock by 2 for the CPU

-- UART Runs at 57.6 Kbps

--

-- Version 1.4 - 21 Nov 2004 - John Kent

-- Changes to make compatible with Spartan3 starter kit version

-- Designed to run with a 50MHz clock input.

-- the VDU divides 50 MHz to generate a 

-- 25 MHz VDU Pixel Clock and a 12.5 MHz CPU clock

-- Changed Monitor ROM signals to make it look like

-- a standard 2K memory block

-- Re-assigned I/O port assignments so it is possible to run KBUG9

-- $E000 - ACIA

-- $E010 - Keyboard

-- $E020 - VDU

-- $E030 - Compact Flash

-- $E040 - Timer

-- $E050 - Bus trap

-- $E060 - Parallel I/O

--

-- Version 1.5 - 3rd February 2007 - John Kent

-- Changed VDU8 to use external clock divider

-- renamed miniUART to ACIA_6850

-- Memory decoding of ROM & IO now uses DAT

--

-- Version 1.6 - 7th Februaury 2007 - John Kent

-- Made ACIA Clock generator an external component

-- Added Generics to VDU and Keyboard

-- Changed decoding

--

-- Version 1.7 - 20th May 2007 - John Kent

-- Added 4 wait states to CF access

-- Removed DAT memory map control of ROM & IO

-- to allow for full use of RAM as a RAM disk.

-- Mapped in all 16 bits of the CF data bus.

-- 

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

--

library ieee;

   use ieee.std_logic_1164.all;

   use IEEE.STD_LOGIC_ARITH.ALL;

   use IEEE.STD_LOGIC_UNSIGNED.ALL;

   use ieee.numeric_std.all;

library unisim;

        use unisim.vcomponents.all;

entity System09 is

  port(

    SysClk      : in  Std_Logic;  -- System Clock input

         Reset_n     : in  Std_logic;  -- Master Reset input (active low)

    LED         : out std_logic;  -- Diagnostic LED Flasher

    -- Memory Interface signals

    ram_csn     : out Std_Logic;

    ram_wrln    : out Std_Logic;

    ram_wrun    : out Std_Logic;

    ram_addr    : out Std_Logic_Vector(16 downto 0);

    ram_data    : inout Std_Logic_Vector(15 downto 0);

         -- Stuff on the peripheral board

         -- PS/2 Keyboard

         kb_clock    : inout Std_logic;

         kb_data     : inout Std_Logic;

         -- PS/2 Mouse interface

--       mouse_clock : in  Std_Logic;

--       mouse_data  : in  Std_Logic;

         -- Uart Interface

    rxbit       : in  Std_Logic;

         txbit       : out Std_Logic;

    rts_n       : out Std_Logic;

    cts_n       : in  Std_Logic;

         -- CRTC output signals

         v_drive     : out Std_Logic;

    h_drive     : out Std_Logic;

    blue_lo     : out std_logic;

    blue_hi     : out std_logic;

    green_lo    : out std_logic;

    green_hi    : out std_logic;

    red_lo      : out std_logic;

    red_hi      : out std_logic;

--         buzzer      : out std_logic;

-- Compact Flash

    cf_rst_n     : out std_logic;

         cf_cs0_n     : out std_logic;

         cf_cs1_n     : out std_logic;

    cf_rd_n      : out std_logic;

    cf_wr_n      : out std_logic;

         cf_cs16_n    : out std_logic;

    cf_a         : out std_logic_vector(2 downto 0);

    cf_d         : inout std_logic_vector(15 downto 0);

--    cf_d         : inout std_logic_vector(7 downto 0);

-- Parallel I/O port

    porta        : inout std_logic_vector(7 downto 0);

    portb        : inout std_logic_vector(7 downto 0);

-- CPU bus

         bus_clk      : out std_logic;

         bus_reset    : out std_logic;

         bus_rw       : out std_logic;

         bus_cs       : out std_logic;

    bus_addr     : out std_logic_vector(15 downto 0);

         bus_data     : inout std_logic_vector(7 downto 0);

-- timer

    timer_out    : out std_logic

         );

end System09;

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

-- Architecture for System09

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

architecture rtl of System09 is

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

  -- constants

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

  constant SYS_Clock_Frequency  : integer := 50000000;  -- FPGA System Clock

  constant PIX_Clock_Frequency  : integer := 25000000;  -- VGA Pixel Clock

  constant CPU_Clock_Frequency  : integer := 12500000;  -- CPU Clock

  constant BAUD_Rate            : integer := 57600;       -- Baud Rate

  constant ACIA_Clock_Frequency : integer := BAUD_Rate * 16;

  type hold_state_type is ( hold_release_state, hold_request_state );

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

  -- Signals

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

  -- Monitor ROM

  signal rom_data_out  : Std_Logic_Vector(7 downto 0);

  signal rom_cs        : std_logic;

  -- UART Interface signals

  signal uart_data_out : Std_Logic_Vector(7 downto 0);

  signal uart_cs       : Std_Logic;

  signal uart_irq      : Std_Logic;

  signal uart_clk       : Std_Logic;

  signal DCD_n         : Std_Logic;

  -- timer

  signal timer_data_out : std_logic_vector(7 downto 0);

  signal timer_cs    : std_logic;

  signal timer_irq   : std_logic;

  -- trap

  signal trap_cs         : std_logic;

  signal trap_data_out   : std_logic_vector(7 downto 0);

  signal trap_irq        : std_logic;

  -- Parallel I/O port

  signal ioport_data_out : std_logic_vector(7 downto 0);

  signal ioport_cs    : std_logic;

  -- compact flash port

  signal cf_data_out : std_logic_vector(7 downto 0);

  signal cf_cs       : std_logic;

  signal cf_rd       : std_logic;

  signal cf_wr       : std_logic;

  signal cf_hold     : std_logic;

  signal cf_release  : std_logic;

  signal cf_count    : std_logic_vector(3 downto 0);

  signal cf_hold_state : hold_state_type;

  -- keyboard port

  signal keyboard_data_out : std_logic_vector(7 downto 0);

  signal keyboard_cs       : std_logic;

  signal keyboard_irq      : std_logic;

  -- RAM

  signal ram_cs      : std_logic; -- memory chip select

  signal ram_wrl     : std_logic; -- memory write lower

  signal ram_wru     : std_logic; -- memory write upper

  signal ram_data_out    : std_logic_vector(7 downto 0);

  -- CPU Interface signals

  signal cpu_reset    : Std_Logic;

  signal cpu_clk      : Std_Logic;

  signal cpu_rw       : std_logic;

  signal cpu_vma      : std_logic;

  signal cpu_halt     : std_logic;

  signal cpu_hold     : std_logic;

  signal cpu_firq     : std_logic;

  signal cpu_irq      : std_logic;

  signal cpu_nmi      : std_logic;

  signal cpu_addr     : std_logic_vector(15 downto 0);

  signal cpu_data_in  : std_logic_vector(7 downto 0);

  signal cpu_data_out : std_logic_vector(7 downto 0);

  -- Dynamic address translation

  signal dat_cs       : std_logic;

  signal dat_addr     : std_logic_vector(7 downto 0);

  -- Video Display Unit

  signal pix_clk      : std_logic;

  signal vdu_cs       : std_logic;

  signal vdu_data_out : std_logic_vector(7 downto 0);

  signal vga_red      : std_logic;

  signal vga_green    : std_logic;

  signal vga_blue     : std_logic;

  -- Flashing Led test signals

  signal countL      : std_logic_vector(23 downto 0);

  signal clock_div   : std_logic_vector(1 downto 0);

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

--

-- CPU09 CPU core

--

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

component cpu09

  port (

         clk:        in std_logic;

    rst:      in        std_logic;

    rw:      out        std_logic;              -- Asynchronous memory interface

    vma:             out        std_logic;

    address:  out       std_logic_vector(15 downto 0);

    data_in:  in        std_logic_vector(7 downto 0);

         data_out: out std_logic_vector(7 downto 0);

         halt:     in  std_logic;

         hold:     in  std_logic;

         irq:      in  std_logic;

         nmi:      in  std_logic;

         firq:     in  std_logic

  );

end component;

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

--

-- SBUG Block RAM Monitor ROM

--

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

component mon_rom

    port (

       clk   : in  std_logic;

       rst   : in  std_logic;

       cs    : in  std_logic;

       rw    : in  std_logic;

       addr  : in  std_logic_vector (10 downto 0);

       wdata : in  std_logic_vector (7 downto 0);

       rdata : out std_logic_vector (7 downto 0)

    );

end component;

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

--

-- Dynamic Address Translation Registers

--

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

component dat_ram

  port (

    clk:      in  std_logic;

         rst:      in  std_logic;

         cs:       in  std_logic;

         rw:       in  std_logic;

         addr_lo:  in  std_logic_vector(3 downto 0);

         addr_hi:  in  std_logic_vector(3 downto 0);

    data_in:  in  std_logic_vector(7 downto 0);

         data_out: out std_logic_vector(7 downto 0)

         );

end component;

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

--

-- 6850 ACIA/UART

--

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

component ACIA_6850

  port (

     clk      : in  Std_Logic;  -- System Clock

     rst      : in  Std_Logic;  -- Reset input (active high)

     cs       : in  Std_Logic;  -- miniUART Chip Select

     rw       : in  Std_Logic;  -- Read / Not Write

     irq      : out Std_Logic;  -- Interrupt

     Addr     : in  Std_Logic;  -- Register Select

     DataIn   : in  Std_Logic_Vector(7 downto 0); -- Data Bus In 

     DataOut  : out Std_Logic_Vector(7 downto 0); -- Data Bus Out

     RxC      : in  Std_Logic;  -- Receive Baud Clock

     TxC      : in  Std_Logic;  -- Transmit Baud Clock

     RxD      : in  Std_Logic;  -- Receive Data

     TxD      : out Std_Logic;  -- Transmit Data

          DCD_n    : in  Std_Logic;  -- Data Carrier Detect

     CTS_n    : in  Std_Logic;  -- Clear To Send

     RTS_n    : out Std_Logic );  -- Request To send

end component;

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

--

-- ACIA Clock divider

--

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

component ACIA_Clock

  generic (

     SYS_Clock_Frequency  : integer :=  SYS_Clock_Frequency;

          ACIA_Clock_Frequency : integer := ACIA_Clock_Frequency

  );

  port (

     clk      : in  Std_Logic;  -- System Clock Input

          ACIA_clk : out Std_logic   -- ACIA Clock output

  );

end component;

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

--

-- Timer module

--

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

component timer

  port (

     clk       : in std_logic;

     rst       : in std_logic;

     cs        : in std_logic;

     rw        : in std_logic;

     addr      : in std_logic;

     data_in   : in std_logic_vector(7 downto 0);

          data_out  : out std_logic_vector(7 downto 0);

          irq       : out std_logic;

     timer_in  : in std_logic;

          timer_out : out std_logic

          );

end component;

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

--

-- Bus Trap logic

--

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

component trap

        port (

         clk        : in  std_logic;

    rst        : in  std_logic;

    cs         : in  std_logic;

    rw         : in  std_logic;

    vma        : in  std_logic;

    addr       : in  std_logic_vector(15 downto 0);

    data_in    : in  std_logic_vector(7 downto 0);

         data_out   : out std_logic_vector(7 downto 0);

         irq        : out std_logic

  );

end component;

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

--

-- Dual 8 bit Parallel I/O module

--

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

component ioport

        port (

         clk       : in  std_logic;

    rst       : in  std_logic;

    cs        : in  std_logic;

    rw        : in  std_logic;

    addr      : in  std_logic_vector(1 downto 0);

    data_in   : in  std_logic_vector(7 downto 0);

         data_out  : out std_logic_vector(7 downto 0);

         porta_io  : inout std_logic_vector(7 downto 0);

         portb_io  : inout std_logic_vector(7 downto 0)

         );

end component;

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

--

-- PS/2 Keyboard

--

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

component keyboard

  generic(

  KBD_Clock_Frequency : integer := CPU_Clock_Frequency

  );

  port(

  clk             : in    std_logic;

  rst             : in    std_logic;

  cs              : in    std_logic;

  rw              : in    std_logic;

  addr            : in    std_logic;

  data_in         : in    std_logic_vector(7 downto 0);

  data_out        : out   std_logic_vector(7 downto 0);

  irq             : out   std_logic;

  kbd_clk         : inout std_logic;

  kbd_data        : inout std_logic

  );

end component;

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

--

-- Video Display Unit.

--

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

component vdu8

      generic(

        VDU_CLOCK_FREQUENCY    : integer := CPU_Clock_Frequency; -- HZ

        VGA_CLOCK_FREQUENCY    : integer := PIX_Clock_Frequency; -- HZ

             VGA_HOR_CHARS          : integer := 80; -- CHARACTERS

             VGA_VER_CHARS          : integer := 25; -- CHARACTERS

             VGA_PIXELS_PER_CHAR    : integer := 8;  -- PIXELS

             VGA_LINES_PER_CHAR     : integer := 16; -- LINES

             VGA_HOR_BACK_PORCH     : integer := 40; -- PIXELS

             VGA_HOR_SYNC           : integer := 96; -- PIXELS

             VGA_HOR_FRONT_PORCH    : integer := 24; -- PIXELS

             VGA_VER_BACK_PORCH     : integer := 13; -- LINES

             VGA_VER_SYNC           : integer := 1;  -- LINES

             VGA_VER_FRONT_PORCH    : integer := 36  -- LINES

      );

      port(

                -- control register interface

      vdu_clk      : in  std_logic;      -- CPU Clock - 12.5MHz

      vdu_rst      : in  std_logic;

                vdu_cs       : in  std_logic;

                vdu_rw       : in  std_logic;

                vdu_addr     : in  std_logic_vector(2 downto 0);

      vdu_data_in  : in  std_logic_vector(7 downto 0);

      vdu_data_out : out std_logic_vector(7 downto 0);

      -- vga port connections

                vga_clk      : in  std_logic;   -- VGA Pixel Clock - 25 MHz

      vga_red_o    : out std_logic;

      vga_green_o  : out std_logic;

      vga_blue_o   : out std_logic;

      vga_hsync_o  : out std_logic;

      vga_vsync_o  : out std_logic

   );

end component;

component BUFG

  port (

                i: in  std_logic;

                o: out std_logic

  );

end component;

begin

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

  -- Instantiation of internal components

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

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

--

-- CPU09 CPU Core

--

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

my_cpu : cpu09  port map (

         clk         => cpu_clk,

    rst       => cpu_reset,

    rw       => cpu_rw,

    vma       => cpu_vma,

    address   => cpu_addr(15 downto 0),

    data_in   => cpu_data_in,

         data_out  => cpu_data_out,

         halt      => cpu_halt,

         hold      => cpu_hold,

         irq       => cpu_irq,

         nmi       => cpu_nmi,

         firq      => cpu_firq

  );

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

--

-- SBUG / KBUG / SYS09BUG Monitor ROM

--

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

my_rom : mon_rom port map (

       clk   => cpu_clk,

                 rst   => cpu_reset,

                 cs    => rom_cs,

                 rw    => '1',

       addr  => cpu_addr(10 downto 0),

                 wdata => cpu_data_out,

       rdata => rom_data_out

    );

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

--

-- Dynamic Address Translation Registers

--

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

my_dat : dat_ram port map (

    clk        => cpu_clk,

         rst        => cpu_reset,

         cs         => dat_cs,

         rw         => cpu_rw,

         addr_hi    => cpu_addr(15 downto 12),

         addr_lo    => cpu_addr(3 downto 0),

    data_in    => cpu_data_out,

         data_out   => dat_addr(7 downto 0)

         );

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

--

-- ACIA/UART Serial interface

--

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

my_ACIA  : ACIA_6850 port map (

         clk         => cpu_clk,

         rst       => cpu_reset,

    cs        => uart_cs,

         rw        => cpu_rw,

    irq       => uart_irq,

    Addr      => cpu_addr(0),

         Datain    => cpu_data_out,

         DataOut   => uart_data_out,

         RxC       => uart_clk,

         TxC       => uart_clk,

         RxD       => rxbit,

         TxD       => txbit,

         DCD_n     => dcd_n,

         CTS_n     => cts_n,

         RTS_n     => rts_n

         );

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

--

-- ACIA Clock

--

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

my_ACIA_Clock : ACIA_Clock

  generic map(

    SYS_Clock_Frequency  => SYS_Clock_Frequency,

         ACIA_Clock_Frequency => ACIA_Clock_Frequency

  )

  port map(

    clk        => SysClk,

    acia_clk   => uart_clk

  );

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

--

-- PS/2 Keyboard Interface

--

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

my_keyboard : keyboard

   generic map (

        KBD_Clock_Frequency => CPU_Clock_frequency

        )

   port map(

        clk          => cpu_clk,

        rst          => cpu_reset,

        cs           => keyboard_cs,

        rw           => cpu_rw,

        addr         => cpu_addr(0),

        data_in      => cpu_data_out(7 downto 0),

        data_out     => keyboard_data_out(7 downto 0),

        irq          => keyboard_irq,

        kbd_clk      => kb_clock,

        kbd_data     => kb_data

        );

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

--

-- Video Display Unit instantiation

--

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

my_vdu : vdu8

  generic map(

      VDU_CLOCK_FREQUENCY    => CPU_Clock_Frequency, -- HZ

      VGA_CLOCK_FREQUENCY    => PIX_Clock_Frequency, -- HZ

           VGA_HOR_CHARS          => 80, -- CHARACTERS

           VGA_VER_CHARS          => 25, -- CHARACTERS

           VGA_PIXELS_PER_CHAR    => 8,  -- PIXELS

           VGA_LINES_PER_CHAR     => 16, -- LINES

           VGA_HOR_BACK_PORCH     => 40, -- PIXELS

           VGA_HOR_SYNC           => 96, -- PIXELS

           VGA_HOR_FRONT_PORCH    => 24, -- PIXELS

           VGA_VER_BACK_PORCH     => 13, -- LINES

           VGA_VER_SYNC           => 1,  -- LINES

           VGA_VER_FRONT_PORCH    => 36  -- LINES

  )

  port map(

                -- Control Registers

                vdu_clk       => cpu_clk,                                        -- 12.5 MHz System Clock in

      vdu_rst       => cpu_reset,

                vdu_cs        => vdu_cs,

                vdu_rw        => cpu_rw,

                vdu_addr      => cpu_addr(2 downto 0),

                vdu_data_in   => cpu_data_out,

                vdu_data_out  => vdu_data_out,

      -- vga port connections

      vga_clk       => pix_clk,                                  -- 25 MHz VDU pixel clock

      vga_red_o     => vga_red,

      vga_green_o   => vga_green,

      vga_blue_o    => vga_blue,

      vga_hsync_o   => h_drive,

      vga_vsync_o   => v_drive

   );

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

--

-- Timer Module

--

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

my_timer  : timer port map (

    clk       => cpu_clk,

         rst       => cpu_reset,

    cs        => timer_cs,

         rw        => cpu_rw,

    addr      => cpu_addr(0),

         data_in   => cpu_data_out,

         data_out  => timer_data_out,

    irq       => timer_irq,

         timer_in  => CountL(5),

         timer_out => timer_out

    );