Subversion Repositories System09

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

--

--  System09 - SoC for the BurchED B5-X300 Spartan2 FPGA board.

--

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

--

-- File name      : System09_BurchED_B5-X300.vhd

--

-- Entity name    : my_system09

--

-- 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           : clock_div     (../vhdl/clock_div.vhd)       System clock divider

--                  flasher       (../vhdl/flasher.vhd)         LED flasher

--                  BED_SRAM      (../vhdl/BED_SRAM.vhd)        BurchED SRAM interface

--                  cpu09         (../vhdl/cpu09.vhd)           CPU core

--                  SYS09BUG_F800 (../spartan2/sys09b5x_b4.vhd) Monitor ROM

--                  dat_ram       (../vhdl/datram.vhd)          Dynamic Address Translation

--                  acia6850      (../vhdl/acia6850.vhd)        ACIA

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

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

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

--                  timer         (../vhdl/timer.vhd)           Timer module

--                  trap               (../vhdl/trap.vhd)            Bus Trap interrupt

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

-- 

-- Author         : John E. Kent      

--                  dilbert57@opencores.org      

-- Memory Map     :

--

-- $0000 - $DFFF System RAM (256K Mapped via DAT)

-- $E000 - ACIA (SWTPc)

-- $E010 - Reserved for SWTPc FD-01 FD1771 FDC

-- $E020 - Keyboard

-- $E030 - VDU

-- $E040 - Reserved for SWTPc MP-T (was Compact Flash)

-- $E050 - Timer

-- $E060 - Bus Trap (Hardware Breakpoint Interrupt Logic)

-- $E070 - Parallel I/O

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

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

-- $E0A0 - Reserved SPP Printer Port

-- $E0B0 - Reserved

-- $E0C0 - Reserved

-- $E100 - $E13F IDE / Compact Flash Card

-- $E140 - $E17F Reserved for Ethernet MAC (XESS)

-- $E180 - $E1BF Reserved for Expansion Slot 0 (XESS)

-- $E1C0 - $E1FF Reserved for Expansion Slot 1 (XESS)

-- $E200 - $EFFF Dual Port RAM interface

-- $F000 - $F7FF Reserved SWTPc DMAF-2

-- $F800 - $FFFF Sys09bug ROM (Read only)

-- $FFF0 - $FFFF DAT - Dynamic Address Translation (Write Only)

--

--

--  Copyright (C) 2003 - 2010 John Kent

--

--  This program is free software: you can redistribute it and/or modify

--  it under the terms of the GNU General Public License as published by

--  the Free Software Foundation, either version 3 of the License, or

--  (at your option) any later version.

--

--  This program is distributed in the hope that it will be useful,

--  but WITHOUT ANY WARRANTY; without even the implied warranty of

--  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

--  GNU General Public License for more details.

--

--  You should have received a copy of the GNU General Public License

--  along with this program.  If not, see <http://www.gnu.org/licenses/>.

--

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

--

--                             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.

--

-- Version 1.8 - 23rd February 2009 - John Kent

-- Renamed mon_rom to SYS09BUG_F800

--

-- Version 1.9 - 5th sepember 2010 - John Kent

-- Added Peripheral bus interface

-- Made the clock divider an external module

-- Rearranged VDU generic signals

-- Changed address decoding

-- Made the SRAM an external module

-- 

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

--

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 my_system09 is

  port(

    clk_in      : in  Std_Logic;  -- System Clock input

         rst_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_a         : out std_logic_vector(2 downto 0);

    cf_d         : inout std_logic_vector(15 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)

         );

end my_system09;

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

-- Architecture for System09

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

architecture rtl of my_system09 is

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

  -- constants

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

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

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

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

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

  constant ACIA_CLK_FREQ : integer := BAUD_RATE * 16;

  type hold_state_type is ( hold_release_state, hold_request_state );

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

  -- Signals

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

  -- Clock signals

  signal sys_clk       : std_logic;

  signal vga_clk       : std_logic;

  -- CPU Interface signals

  signal cpu_rst       : Std_Logic;

  signal cpu_clk       : Std_Logic;

  signal cpu_vma       : std_logic;

  signal cpu_addr      : std_logic_vector(15 downto 0);

  signal cpu_rw        : std_logic;

  signal cpu_data_in   : std_logic_vector(7 downto 0);

  signal cpu_data_out  : std_logic_vector(7 downto 0);

  signal cpu_firq      : std_logic;

  signal cpu_irq       : std_logic;

  signal cpu_nmi       : std_logic;

  signal cpu_halt      : std_logic;

  signal cpu_hold      : std_logic;

  -- Dynamic address translation

  signal dat_cs       : std_logic;

  signal dat_addr     : std_logic_vector(7 downto 0);

  -- Monitor ROM

  signal rom_data_out  : Std_Logic_Vector(7 downto 0);

  signal rom_cs        : std_logic;

  -- UART/ACIA 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;

  -- Keyboard port

  signal kbd_data_out  : std_logic_vector(7 downto 0);

  signal kbd_cs        : std_logic;

  signal kbd_irq       : std_logic;

  -- Video Display Unit

  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;

  -- Timer

  signal tmr_data_out  : std_logic_vector(7 downto 0);

  signal tmr_cs        : std_logic;

  signal tmr_irq       : std_logic;

  -- Trap Hardware break point

  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 pio_data_out  : std_logic_vector(7 downto 0);

  signal pio_cs        : std_logic;

  -- Peripheral bus

  signal pb_data_out   : std_logic_vector(7 downto 0);

  signal pb_cs         : std_logic;

  signal pb_hold       : std_logic;

  -- Compact Flash on peripheral bus

  signal cf_cs         : std_logic;

  -- SRAM

  signal ram_cs        : std_logic; -- memory chip select

  signal ram_data_out  : std_logic_vector(7 downto 0);

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

--

--                     Clock generator

--

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

component clock_div

  port(

    clk_in      : in  std_Logic;  -- System Clock input

         sys_clk     : out std_logic;  -- System Clock Out    (1/1)

         vga_clk     : out std_logic;  -- VGA Pixel Clock Out (1/2)

    cpu_clk     : out std_logic   -- CPU Clock Out       (1/4)

  );

end component;

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

--

--                      LED Flasher

--

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

component flasher

  port (

    clk      : in  std_logic;           -- Clock input

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

    LED      : out Std_Logic            -- LED output        

  );

end component;

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

--

--           B5 SRAM interface ($0000 - $DFFF)

--

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

component BED_SRAM

  port (

    --

    -- CPU Interface signals

    --

    clk       : in  std_logic;                     -- System Clock (twice the CPU clock)

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

    cs        : in  std_logic;                     -- RAM Chip Select

    addr      : in  std_logic_vector(17 downto 0); -- RAM address bus

    rw        : in  std_logic;                     -- Read / Not Write

    data_in   : in  std_logic_vector(7 downto 0);  -- Data Bus In 

    data_out  : out std_logic_vector(7 downto 0);  -- Data Bus Out

    --

    -- BED_SRAM 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)

    );

end component;

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

--

-- CPU09 CPU core

--

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

component cpu09

  port (

         clk      :     in  std_logic;

    rst      : in  std_logic;

    vma      :  out std_logic;

    addr     : out std_logic_vector(15 downto 0);

    rw       :  out std_logic;          -- Asynchronous memory interface

    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;

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

--

-- 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;

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

--

-- SBUG Block RAM Monitor ROM

--

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

component SYS09BUG_F800

    port (

       clk      : in  std_logic;

       rst      : in  std_logic;

       cs       : in  std_logic;

       addr     : in  std_logic_vector (10 downto 0);

       rw       : in  std_logic;

       data_in  : in  std_logic_vector (7 downto 0);

       data_out : out std_logic_vector (7 downto 0)

    );

end component;

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

--

-- 6850 ACIA/UART

--

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

component acia6850

  port (

     clk      : in  Std_Logic;  -- System Clock

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

     cs       : in  Std_Logic;  -- miniUART Chip Select

     addr     : in  Std_Logic;  -- Register Select

     rw       : in  Std_Logic;  -- Read / Not Write

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

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

     irq      : out Std_Logic;  -- Interrupt

     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_CLK_FREQ  : integer :=  SYS_CLK_FREQ;

          ACIA_CLK_FREQ : integer := ACIA_CLK_FREQ

  );

  port (

     clk      : in  Std_Logic;  -- System Clock Input

          ACIA_clk : out Std_logic   -- ACIA Clock output

  );

end component;

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

--

-- PS/2 Keyboard

--

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

component keyboard

  generic(

    KBD_CLK_FREQ : integer := CPU_CLK_FREQ

  );

  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(

    VGA_CLK_FREQ           : integer := VGA_CLK_FREQ; -- 25MHz

         VGA_HOR_CHARS          : integer := 80; -- CHARACTERS 25.6us

         VGA_HOR_CHAR_PIXELS    : integer := 8;  -- PIXELS 0.32us

         VGA_HOR_FRONT_PORCH    : integer := 16; -- PIXELS 0.64us (0.94us)

         VGA_HOR_SYNC           : integer := 96; -- PIXELS 3.84us (3.77us)

         VGA_HOR_BACK_PORCH     : integer := 48; -- PIXELS 1.92us (1.89us)

         VGA_VER_CHARS          : integer := 25; -- CHARACTERS 12.8ms

         VGA_VER_CHAR_LINES     : integer := 16; -- LINES 0.512ms

         VGA_VER_FRONT_PORCH    : integer := 10; -- LINES 0.320ms

         VGA_VER_SYNC           : integer := 2;  -- LINES 0.064ms

         VGA_VER_BACK_PORCH     : integer := 34  -- LINES 1.088ms

  );

  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;

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

--

-- Timer module

--

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

component timer

  port (

    clk       : in std_logic;

    rst       : in std_logic;

    cs        : in std_logic;

    addr      : in std_logic;

    rw        : 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

  );

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;

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

--

-- Peripheral Bus interface (IDE CF) ($E100 - $E1FF)

--

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

component peripheral_bus is

  port (

    --

    -- CPU Interface signals

    --

    clk      : in  std_logic;                     -- System Clock

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

    cs       : in  std_logic;                     -- Peripheral Bus Chip Select

    addr     : in  std_logic_vector(7 downto 0);  -- Register Select

    rw       : in  std_logic;                     -- Read / Not Write

    data_in  : in  std_logic_vector(7 downto 0);  -- Data Bus In 

    data_out : out std_logic_vector(7 downto 0);  -- Data Bus Out

    hold     : out std_logic;                     -- Hold bus cycle output

    --

    -- Peripheral Bus Interface Signals

    -- IO + ($00 - $FF) 

    -- (for compatibility with XSA-3S1000 / XST 3.0)

    --

    pb_rd_n  : out   std_logic; -- ide pin 25

    pb_wr_n  : out   std_logic; -- ide pin 23

    pb_addr  : out   std_logic_vector( 4 downto 0);

    pb_data  : inout std_logic_vector(15 downto 0);

    -- Peripheral chip selects on Peripheral Bus 

    ide_cs   : out  std_logic;  -- IDE / CF interface ($00 - $3F)

    eth_cs   : out  std_logic;  -- Ethernet interface ($40 - $7F)

    sl1_cs   : out  std_logic;  -- Expansion slot 1   ($80 - $BF)

    sl2_cs   : out  std_logic   -- Expansion slot 2   ($C0 - $FF)

    );

end component;

component BUFG

  port (

                i: in  std_logic;

                o: out std_logic

  );

end component;

begin

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

-- Instantiation of internal components

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

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

--

-- Clock generator

--

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

my_clock_div: clock_div port map (

    clk_in   => clk_in,   -- Clock input

    sys_clk  => sys_clk,  -- System Clock Out    (1/1)

    vga_clk  => vga_clk,  -- VGA Pixel Clock Out (1/2)

    cpu_clk  => cpu_clk   -- CPU Clock Out       (1/4)

  );

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

--

-- LED Flasher

--

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

my_LED_flasher : flasher port map (

    clk      => cpu_clk,

    rst      => cpu_rst,

    LED      => LED

  );

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

--

-- CPU09 CPU Core

--