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[/] [System09/] [trunk/] [rtl/] [System09_BurchED_B5-X300/] [System09_BurchED_B5-X300.vhd] - Rev 108
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--===========================================================================---- -- -- 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_BurchED_B5-X300.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 -- SYS09BUG_F800 (sys09b5x_b4.vhd) Monitor ROM -- dat_ram (datram.vhd) Dynamic Address Translation -- acia6850 (acia6850.vhd) ACIA / MiniUART -- 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 : -- 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) -- --===========================================================================---- -- -- 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 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 System09; ------------------------------------------------------------------------------- -- Architecture for System09 ------------------------------------------------------------------------------- architecture rtl of 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 -- ---------------------------------------- my_cpu : cpu09 port map ( clk => cpu_clk, rst => cpu_rst, vma => cpu_vma, addr => cpu_addr(15 downto 0), rw => cpu_rw, 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 ); ---------------------------------------- -- -- Dynamic Address Translation Registers -- ---------------------------------------- my_dat : dat_ram port map ( clk => cpu_clk, rst => cpu_rst, 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) ); ---------------------------------------- -- -- SBUG / KBUG / SYS09BUG Monitor ROM -- ---------------------------------------- my_rom : SYS09BUG_F800 port map ( clk => cpu_clk, rst => cpu_rst, cs => rom_cs, addr => cpu_addr(10 downto 0), rw => '1', data_in => cpu_data_out, data_out => rom_data_out ); ---------------------------------------- -- -- ACIA/UART Serial interface -- ---------------------------------------- my_acia : acia6850 port map ( clk => cpu_clk, rst => cpu_rst, cs => uart_cs, addr => cpu_addr(0), rw => cpu_rw, data_in => cpu_data_out, data_out => uart_data_out, irq => uart_irq, 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_CLK_FREQ => SYS_CLK_FREQ, ACIA_CLK_FREQ => ACIA_CLK_FREQ ) port map( clk => sys_clk, acia_clk => uart_clk ); ---------------------------------------- -- -- PS/2 Keyboard Interface -- ---------------------------------------- my_keyboard : keyboard generic map ( KBD_CLK_FREQ => CPU_CLK_FREQ ) port map( clk => cpu_clk, rst => cpu_rst, cs => kbd_cs, addr => cpu_addr(0), rw => cpu_rw, data_in => cpu_data_out(7 downto 0), data_out => kbd_data_out(7 downto 0), irq => kbd_irq, kbd_clk => kb_clock, kbd_data => kb_data ); ------------------------------------------------ -- -- Video Display Unit instantiation ($E030-$E03F) -- ------------------------------------------------- my_vdu : vdu8 generic map( VGA_CLK_FREQ => VGA_CLK_FREQ, -- 25MHZ VGA_HOR_CHARS => 80, -- CHARACTERS 25.6us VGA_HOR_CHAR_PIXELS => 8, -- PIXELS 0.32us VGA_HOR_FRONT_PORCH => 16, -- PIXELS 0.64us VGA_HOR_SYNC => 96, -- PIXELS 3.84us VGA_HOR_BACK_PORCH => 48, -- PIXELS 1.92us VGA_VER_CHARS => 25, -- CHARACTERS 12.8ms VGA_VER_CHAR_LINES => 16, -- LINES 0.512ms VGA_VER_FRONT_PORCH => 10, -- LINES 0.320ms VGA_VER_SYNC => 2, -- LINES 0.064ms VGA_VER_BACK_PORCH => 34 -- LINES 1.088ms ) port map( -- CPU Control Registers interface vdu_clk => cpu_clk, -- 12.5 MHz System Clock in vdu_rst => cpu_rst, vdu_cs => vdu_cs, vdu_rw => cpu_rw, vdu_addr => cpu_addr(2 downto 0), vdu_data_in => cpu_data_out, vdu_data_out => vdu_data_out, -- vga port connections vga_clk => vga_clk, -- 25 MHz VDU pixel clock vga_red_o => vga_red, vga_green_o => vga_green, vga_blue_o => vga_blue, vga_hsync_o => h_drive, vga_vsync_o => v_drive ); ---------------------------------------- -- -- Timer Module -- ---------------------------------------- my_timer : timer port map ( clk => cpu_clk, rst => cpu_rst, cs => tmr_cs, rw => cpu_rw, addr => cpu_addr(0), data_in => cpu_data_out, data_out => tmr_data_out, irq => tmr_irq ); ---------------------------------------- -- -- Bus Trap Interrupt logic -- ---------------------------------------- my_trap : trap port map ( clk => cpu_clk, rst => cpu_rst, cs => trap_cs, rw => cpu_rw, vma => cpu_vma, addr => cpu_addr, data_in => cpu_data_out, data_out => trap_data_out, irq => trap_irq ); ---------------------------------------- -- -- Parallel I/O Port -- ---------------------------------------- my_ioport : ioport port map ( clk => cpu_clk, rst => cpu_rst, cs => pio_cs, rw => cpu_rw, addr => cpu_addr(1 downto 0), data_in => cpu_data_out, data_out => pio_data_out, porta_io => porta, portb_io => portb ); ------------------------------------------------ -- -- 16 bit Peripheral Bus interface ($E100-$E1FF) -- ------------------------------------------------ my_pb : peripheral_bus port map ( -- -- CPU Interface signals -- clk => cpu_clk, rst => cpu_rst, cs => pb_cs, addr => cpu_addr(7 downto 0), rw => cpu_rw, data_in => cpu_data_out, data_out => pb_data_out, hold => pb_hold, -- -- Peripheral Bus Interface Signals -- IO + ($00 - $FF) -- pb_rd_n => cf_rd_n, pb_wr_n => cf_wr_n, pb_addr(2 downto 0) => cf_a, pb_addr(4 downto 3) => open, pb_data => cf_d, -- Peripheral chip selects on Peripheral Bus ide_cs => cf_cs, eth_cs => open, sl1_cs => open, sl2_cs => open ); ----------------------------------------------- -- -- BED SRAM interface (256KBytes) ($0000-$DFFF) -- ----------------------------------------------- my_bed_sram : BED_SRAM port map ( -- -- CPU Interface signals -- clk => vga_clk, -- VGA Clock (twice the CPU clock) rst => cpu_rst, -- Reset input (active high) cs => ram_cs, -- RAM Chip Select addr(17 downto 12) => dat_addr( 5 downto 0), -- High RAM address goes to the DAT addr(11 downto 0) => cpu_addr(11 downto 0), -- Low RAM address goes to the CPU rw => cpu_rw, -- Read / Not Write data_in => cpu_data_out, -- Data Bus In data_out => ram_data_out, -- Data Bus Out -- -- BED_SRAM Interface Signals -- ram_csn => ram_csn, ram_wrln => ram_wrln, ram_wrun => ram_wrun, ram_addr => ram_addr, ram_data => ram_data ); ---------------------------------------------------------------------- -- -- Process to decode memory map -- ---------------------------------------------------------------------- mem_decode: process( dat_addr, cpu_addr, cpu_rw, cpu_vma, rom_data_out, uart_data_out, kbd_data_out, vdu_data_out, tmr_data_out, trap_data_out, pio_data_out, bus_data, pb_data_out, ram_data_out ) begin rom_cs <= '0'; -- read ROM dat_cs <= '0'; -- write DAT ram_cs <= '0'; uart_cs <= '0'; kbd_cs <= '0'; vdu_cs <= '0'; tmr_cs <= '0'; trap_cs <= '0'; pio_cs <= '0'; bus_cs <= '0'; pb_cs <= '0'; -- -- ROM / DAT $FF00 - $FFFF -- if cpu_addr( 15 downto 8 ) = "11111111" then cpu_data_in <= rom_data_out; rom_cs <= cpu_vma; -- read ROM dat_cs <= cpu_vma; -- write DAT else -- -- Decode on 4K Byte boundaries -- case dat_addr(3 downto 0) is when "1111" => -- $F000 - $FFFF if cpu_addr(11) = '1' then -- -- SBUG/KBUG/SYS09BUG Monitor ROM $F800 - $FFFF -- cpu_data_in <= rom_data_out; rom_cs <= cpu_vma; else -- -- SRAM $F000 - $F7FF -- Future use DMAF-2 Floppy Disk controller -- cpu_data_in <= ram_data_out; ram_cs <= cpu_vma; end if; -- -- IO Devices $EXXX - $EXXX -- when "1110" => -- -- Decode on 256 Byte boundaries -- IO device $E0XX - $E7XX -- case cpu_addr(10 downto 8) is when "000" => -- -- Decode I/O Devices on 16 byte boundaries -- IO device $E00X - $E0FX -- case cpu_addr(7 downto 4) is -- -- UART / ACIA $E000 -- when "0000" => -- $E000 cpu_data_in <= uart_data_out; uart_cs <= cpu_vma; -- -- WD1771 FDC sites at $E010-$E01F -- -- -- Keyboard port $E020 - $E02F -- when "0010" => -- $E020 cpu_data_in <= kbd_data_out; kbd_cs <= cpu_vma; -- -- VDU port $E030 - $E03F -- when "0011" => -- $E030 cpu_data_in <= vdu_data_out; vdu_cs <= cpu_vma; -- -- Reserved $E040 - $E04F -- -- -- Timer $E050 - $E05F -- when "0101" => -- $E050 cpu_data_in <= tmr_data_out; tmr_cs <= cpu_vma; -- -- Bus Trap Logic $E060 - $E06F -- when "0110" => -- $E060 cpu_data_in <= trap_data_out; trap_cs <= cpu_vma; -- -- Parallel I/O port $E070 - $E07F -- when "0111" => -- $E070 cpu_data_in <= pio_data_out; pio_cs <= cpu_vma; -- -- Undefined / Extension Bus $E080 - $E0FF -- when others => -- $E080 to $E0FF cpu_data_in <= bus_data; bus_cs <= cpu_vma; end case; -- -- Peripheral Bus $E100 - $E1FF -- when "001" => cpu_data_in <= pb_data_out; pb_cs <= cpu_vma; -- -- Map RAM at $E200 - $EFFF Just in case we need driver space. -- when others => cpu_data_in <= ram_data_out; ram_cs <= cpu_vma; end case; -- -- Everything else is RAM $0000 - $DFFF -- when others => cpu_data_in <= ram_data_out; ram_cs <= cpu_vma; end case; end if; end process; -- -- Interrupts and other bus control signals -- interrupts : process( rst_n, pb_hold, uart_irq, trap_irq, tmr_irq, kbd_irq ) begin cpu_rst <= not rst_n; -- CPU reset is active high cpu_irq <= uart_irq or kbd_irq; cpu_nmi <= trap_irq; cpu_firq <= tmr_irq; cpu_halt <= '0'; cpu_hold <= pb_hold; end process; -- -- CPU bus signals -- my_bus : process( cpu_clk, cpu_rst, cpu_rw, cpu_addr, cpu_data_out ) begin bus_clk <= cpu_clk; bus_reset <= cpu_rst; bus_rw <= cpu_rw; bus_addr <= cpu_addr; if( cpu_rw = '1' ) then bus_data <= (others => 'Z'); else bus_data <= cpu_data_out; end if; end process; -- -- Assign VDU VGA colour output -- only 8 colours are handled. -- my_vga_out: process( vga_red, vga_green, vga_blue ) begin red_lo <= vga_red; red_hi <= vga_red; green_lo <= vga_green; green_hi <= vga_green; blue_lo <= vga_blue; blue_hi <= vga_blue; end process; -- -- CF card chip selects ($E100 - $E13F) -- Located on peripheral bus -- my_cf_decode: process( cpu_rst, cpu_addr, cf_cs ) begin cf_cs0_n <= not( cf_cs and not cpu_addr(4)); cf_cs1_n <= not( cf_cs and cpu_addr(4)); cf_rst_n <= not cpu_rst; end process; end rtl; --===================== End of architecture =======================--
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