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[/] [System09/] [rev_86/] [rtl/] [System09_Xess_XSA-3S1000/] [System09_Xess_XSA-3S1000.vhd] - Rev 168
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--===========================================================================---- -- -- S Y N T H E Z I A B L E System09 - SOC. -- -- www.OpenCores.Org - February 2007 -- This core adheres to the GNU public license -- -- File name : System09_Xess_XSA-3S1000.vhd -- -- Purpose : Top level file for 6809 compatible system on a chip -- Designed with Xilinx XC3S1000 Spartan 3 FPGA. -- Implemented With XESS XSA-3S1000 FPGA board. -- *** Note *** -- This configuration can run Flex9 however it only has -- 32k bytes of user memory and the VDU is monochrome -- The design needs to be updated to use the SDRAM on -- the XSA-3S1000 board. -- This configuration also lacks a DAT so cannot use -- the RAM Disk features of SYS09BUG. -- -- Dependencies : ieee.Std_Logic_1164 -- ieee.std_logic_unsigned -- ieee.std_logic_arith -- ieee.numeric_std -- unisim.vcomponents -- -- Uses : mon_rom (sys09bug_rom4k_b16.vhd) Sys09Bug Monitor ROM -- cpu09 (cpu09.vhd) CPU core -- ACIA_6850 (ACIA_6850.vhd) ACIA / UART -- (ACIA_RX.vhd) -- (ACIA_TX.vhd) -- ACIA_Clock (ACIA_Clock.vhd) ACIA clock. -- keyboard (keyboard.vhd) PS/2 Keyboard interface -- (ps2_keyboard.vhd) -- (keymap_rom_slice.vhd) Key map table -- vdu8_mono (vdu8_mono.vhd) Monochrome VDU -- (char_rom2k_b16.vhd) -- (ram2k_b16.vhd) -- timer (timer.vhd) Interrupt timer -- trap (trap.vhd) Bus condition trap logic -- flex_ram (flex9_ram8k_b16.vhd) Flex operating system -- ram_32K (ram32k_b16.vhd) 32 KBytes of Block RAM -- -- -- Author : John E. Kent -- dilbert57@opencores.org -- -- Memory Map : -- -- $0000 - User program RAM (32K Bytes) -- $C000 - Flex Operating System memory (8K Bytes) -- $E000 - ACIA (SWTPc) -- $E010 - Reserved for FD1771 FDC (SWTPc) -- $E020 - Keyboard -- $E030 - VDU -- $E040 - IDE / Compact Flash interface -- $E050 - Timer -- $E060 - Bus trap -- $E070 - Reserced for Parallel I/O (B5-X300) -- $E080 - Reserved for 6821 PIA (?) (SWTPc) -- $E090 - Reserved for 6840 PTM (?) (SWTPc) -- $F000 - Sys09Bug monitor Program (4K Bytes) -- --===========================================================================---- -- -- 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 2.0 - 2 September 2004 - John Kent -- ported to Digilent Xilinx Spartan3 starter board -- removed Compact Flash and Trap Logic. -- Replaced SBUG with KBug9s -- -- Version 3.0 - 29th August 2006 - John Kent -- Adapted to XSA-3S1000 board. -- Removed DAT and miniUART. -- Used 32KBytes of Block RAM. -- -- Version 3.1 - 15th January 2007 - John Kent -- Modified vdu8 interface -- Added a clock divider -- -- Version 3.2 - 25th February 2007 - John Kent -- reinstated ACIA_6850 and ACIA_Clock -- Updated VDU8 & Keyboard with generic parameters -- Defined Constants for clock speed calculations -- -- Version 3.3 - 1st July 2007 - John Kent -- Made VDU mono to save on one RAMB16 -- Used distributed memory for Key Map ROM to save one RAMB16 -- Added Flex RAM at $C000 to $DFFF using 4 spare RAMB16s -- Added timer and trap logic -- Added IDE Interface for Compact Flash -- Replaced KBug9s and stack with Sys09Bug. -- -- Version 4.0 - 1st February 2008 - John kent -- Replaced Block RAM with SDRAM Interface -- Modified Hold timing for SDRAM -- Added CF and Ethernet interface -- via the 16 bit peripheral bus at $E100 -- --===========================================================================-- 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 work; use work.common.all; use WORK.xsasdram.all; library unisim; use unisim.vcomponents.all; entity my_system09 is port( CLKA : in Std_Logic; -- 100MHz Clock input SW2_N : in Std_logic; -- Master Reset input (active low) SW3_N : in Std_logic; -- Non Maskable Interrupt input (active low) -- PS/2 Keyboard ps2_clk : inout Std_logic; ps2_dat : inout Std_Logic; -- CRTC output signals vga_vsync_n : out Std_Logic; vga_hsync_n : out Std_Logic; vga_blue : out std_logic_vector(2 downto 0); vga_green : out std_logic_vector(2 downto 0); vga_red : out std_logic_vector(2 downto 0); -- RS232 Port RS232_RXD : in Std_Logic; RS232_TXD : out Std_Logic; RS232_CTS : in Std_Logic; RS232_RTS : out Std_Logic; -- Status 7 segment LED -- S : out std_logic_vector(7 downto 0); -- SDRAM side SDRAM_clkfb : in std_logic; -- feedback SDRAM clock after PCB delays SDRAM_clkout : out std_logic; -- clock to SDRAM SDRAM_CKE : out std_logic; -- clock-enable to SDRAM SDRAM_CS_N : out std_logic; -- chip-select to SDRAM SDRAM_RAS_N : out std_logic; -- SDRAM row address strobe SDRAM_CAS_N : out std_logic; -- SDRAM column address strobe SDRAM_WE_N : out std_logic; -- SDRAM write enable SDRAM_BA : out std_logic_vector(1 downto 0); -- SDRAM bank address SDRAM_A : out std_logic_vector(12 downto 0); -- SDRAM row/column address SDRAM_D : inout std_logic_vector(15 downto 0); -- data from SDRAM SDRAM_DQMH : out std_logic; -- enable upper-byte of SDRAM databus if true SDRAM_DQML : out std_logic; -- enable lower-byte of SDRAM databus if true -- Peripheral I/O bus $E100 - $E1FF PB_RD_N : out std_logic; PB_WR_N : out std_logic; PB_A : out std_logic_vector(4 downto 0); PB_D : inout std_logic_vector(15 downto 0); -- IDE Compact Flash $E100 - $E13F ide_dmack_n : out std_logic; ide_cs0_n : out std_logic; ide_cs1_n : out std_logic; -- Ethernet $E140 - $E17F ether_cs_n : out std_logic; ether_aen : out std_logic; -- Ethernet address enable not ether_bhe_n : out std_logic; -- Ethernet bus high enable ether_clk : in std_logic; -- Ethernet clock ether_rdy : in std_logic; -- Ethernet ready ether_irq : in std_logic; -- Ethernet irq - Shared with BAR6 -- Slot 1 $E180 - $E1BF slot1_cs_n : out std_logic; -- slot1_irq : in std_logic; -- Slot 2 $E1C0 - $E1FF slot2_cs_n : out std_logic; -- slot2_irq : in std_logic; -- Disable Flash FLASH_CE_N : out std_logic ); end My_System09; ------------------------------------------------------------------------------- -- Architecture for System09 ------------------------------------------------------------------------------- architecture rtl of my_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 := 25000000; -- 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 ----------------------------------------------------------------------------- signal rst_n : Std_logic; -- Master Reset input (active low) signal nmi_n : Std_logic; -- Non Maskable Interrupt input (active low) -- BOOT ROM signal rom_cs : Std_logic; signal rom_data_out : Std_Logic_Vector(7 downto 0); -- Flex Memory & Monitor Stack signal flex_cs : Std_logic; signal flex_data_out : Std_Logic_Vector(7 downto 0); -- ACIA/UART Interface signals signal acia_data_out : Std_Logic_Vector(7 downto 0); signal acia_cs : Std_Logic; signal acia_irq : Std_Logic; signal acia_clk : Std_Logic; signal rxd : Std_Logic; signal txd : Std_Logic; signal DCD_n : Std_Logic; signal RTS_n : Std_Logic; signal CTS_n : Std_Logic; -- 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_data_out : std_logic_vector(7 downto 0); signal ram_hold : std_logic; -- hold off slow accesses -- 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 vdu_cs : std_logic; signal vdu_data_out : std_logic_vector(7 downto 0); signal vga_red_o : std_logic; signal vga_green_o : std_logic; signal vga_blue_o : 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; -- Peripheral Bus port signal pb_data_out : std_logic_vector(7 downto 0); signal pb_cs : std_logic; -- peripheral bus chip select signal pb_wru : std_logic; -- upper byte write strobe signal pb_wrl : std_logic; -- lower byte write strobe signal pb_rdu : std_logic; -- upper byte read strobe signal pb_rdl : std_logic; -- lower byte read strobe signal pb_hold : std_logic; -- hold peripheral bus access signal pb_release : std_logic; -- release hold of peripheral bus signal pb_count : std_logic_vector(3 downto 0); -- hold counter signal pb_hold_state : hold_state_type; signal pb_wreg : std_logic_vector(7 downto 0); -- lower byte write register signal pb_rreg : std_logic_vector(7 downto 0); -- lower byte read register -- Peripheral chip selects on Peripheral Bus signal ide_cs : std_logic; -- IDE CF interface signal ether_cs : std_logic; -- Ethernet interface signal slot1_cs : std_logic; -- Expansion slot 1 signal slot2_cs : std_logic; -- Expansion slot 2 -- SDRAM constant FREQ : natural := 100_000; -- operating frequency in KHz constant CLK_DIV : real := 2.0; -- divisor for FREQ (can only be 1.0, 1.5, 2.0, 2.5, 3.0, 4.0, 5.0, 8.0 or 16.0) constant PIPE_EN : boolean := false; -- if true, enable pipelined read operations constant MAX_NOP : natural := 10000; -- number of NOPs before entering self-refresh constant MULTIPLE_ACTIVE_ROWS : boolean := false; -- if true, allow an active row in each bank constant DATA_WIDTH : natural := 16; -- host & SDRAM data width constant NROWS : natural := 8192; -- number of rows in SDRAM array constant NCOLS : natural := 512; -- number of columns in SDRAM array constant HADDR_WIDTH : natural := 24; -- host-side address width constant SADDR_WIDTH : natural := 13; -- SDRAM-side address width signal rst_i : std_logic; -- internal reset signal signal clk_i : std_logic; -- internal master clock signal signal lock : std_logic; -- SDRAM clock DLL lock indicator -- signals that go through the SDRAM host-side interface signal opBegun : std_logic; -- SDRAM operation started indicator signal earlyBegun : std_logic; -- SDRAM operation started indicator signal ramDone : std_logic; -- SDRAM operation complete indicator signal rdDone : std_logic; -- SDRAM read operation complete indicator signal wrDone : std_logic; -- SDRAM write operation complete indicator signal hAddr : std_logic_vector(HADDR_WIDTH-1 downto 0); -- host address bus signal hDIn : std_logic_vector(DATA_WIDTH-1 downto 0); -- host-side data to SDRAM signal hDOut : std_logic_vector(DATA_WIDTH-1 downto 0); -- host-side data from SDRAM signal hRd : std_logic; -- host-side read control signal signal hWr : std_logic; -- host-side write control signal signal rdPending : std_logic; -- read operation pending in SDRAM pipeline type ram_rd_type is (rd_state0, rd_state1, rd_state2, rd_state3); type ram_wr_type is (wr_state0, wr_state1, wr_state2, wr_state3, wr_state4); signal ram_rd_state : ram_rd_type; signal ram_wr_state : ram_wr_type; -- signal BaudCount : std_logic_vector(5 downto 0); signal CountL : std_logic_vector(23 downto 0); signal clk_count : std_logic_vector(0 downto 0); signal Clk25 : std_logic; signal pix_clk : std_logic; ----------------------------------------------------------------- -- -- 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; ---------------------------------------- -- -- 4K 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 (11 downto 0); rdata : out std_logic_vector (7 downto 0); wdata : in std_logic_vector (7 downto 0) ); end component; ---------------------------------------- -- -- 8KBytes Block RAM for FLEX9 -- $C000 - $DFFF -- ---------------------------------------- component flex_ram Port ( clk : in std_logic; rst : in std_logic; cs : in std_logic; rw : in std_logic; addr : in std_logic_vector (12 downto 0); rdata : out std_logic_vector (7 downto 0); wdata : in std_logic_vector (7 downto 0) ); end component; ----------------------------------------------------------------- -- -- 6850 Compatible 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; ---------------------------------------- -- -- 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 - 25MHz 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; 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 ); 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; ---------------------------------------- -- -- 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; component XSASDRAMCntl generic( FREQ : natural := FREQ; -- operating frequency in KHz CLK_DIV : real := CLK_DIV; -- divisor for FREQ (can only be 1.0, 1.5, 2.0, 2.5, 3.0, 4.0, 5.0, 8.0 or 16.0) PIPE_EN : boolean := PIPE_EN; -- if true, enable pipelined read operations MAX_NOP : natural := MAX_NOP; -- number of NOPs before entering self-refresh MULTIPLE_ACTIVE_ROWS : boolean := MULTIPLE_ACTIVE_ROWS; -- if true, allow an active row in each bank DATA_WIDTH : natural := DATA_WIDTH; -- host & SDRAM data width NROWS : natural := NROWS; -- number of rows in SDRAM array NCOLS : natural := NCOLS; -- number of columns in SDRAM array HADDR_WIDTH : natural := HADDR_WIDTH; -- host-side address width SADDR_WIDTH : natural := SADDR_WIDTH -- SDRAM-side address width ); port( -- host side clk : in std_logic; -- master clock bufclk : out std_logic; -- buffered master clock clk1x : out std_logic; -- host clock sync'ed to master clock (and divided if CLK_DIV>1) clk2x : out std_logic; -- double-speed host clock lock : out std_logic; -- true when host clock is locked to master clock rst : in std_logic; -- reset rd : in std_logic; -- initiate read operation wr : in std_logic; -- initiate write operation earlyOpBegun : out std_logic; -- read/write/self-refresh op begun (async) opBegun : out std_logic; -- read/write/self-refresh op begun (clocked) rdPending : out std_logic; -- read operation(s) are still in the pipeline done : out std_logic; -- read or write operation is done rdDone : out std_logic; -- read done and data is available hAddr : in std_logic_vector(HADDR_WIDTH-1 downto 0); -- address from host hDIn : in std_logic_vector(DATA_WIDTH-1 downto 0); -- data from host hDOut : out std_logic_vector(DATA_WIDTH-1 downto 0); -- data to host status : out std_logic_vector(3 downto 0); -- diagnostic status of the FSM -- SDRAM side sclkfb : in std_logic; -- clock from SDRAM after PCB delays sclk : out std_logic; -- SDRAM clock sync'ed to master clock cke : out std_logic; -- clock-enable to SDRAM cs_n : out std_logic; -- chip-select to SDRAM ras_n : out std_logic; -- SDRAM row address strobe cas_n : out std_logic; -- SDRAM column address strobe we_n : out std_logic; -- SDRAM write enable ba : out std_logic_vector(1 downto 0); -- SDRAM bank address bits sAddr : out std_logic_vector(SADDR_WIDTH-1 downto 0); -- SDRAM row/column address sData : inout std_logic_vector(DATA_WIDTH-1 downto 0); -- SDRAM in/out databus dqmh : out std_logic; -- high databits I/O mask dqml : out std_logic -- low databits I/O mask ); end component; -- -- Clock buffer -- component BUFG Port ( i: in std_logic; o: out std_logic ); end component; begin ----------------------------------------------------------------------------- -- Instantiation of internal components ----------------------------------------------------------------------------- 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 ); my_rom : mon_rom port map ( clk => cpu_clk, rst => cpu_reset, cs => rom_cs, rw => '1', addr => cpu_addr(11 downto 0), wdata => cpu_data_out, rdata => rom_data_out ); my_flex : flex_ram port map ( clk => cpu_clk, rst => cpu_reset, cs => flex_cs, rw => cpu_rw, addr => cpu_addr(12 downto 0), rdata => flex_data_out, wdata => cpu_data_out ); my_acia : ACIA_6850 port map ( clk => cpu_clk, rst => cpu_reset, cs => acia_cs, rw => cpu_rw, irq => acia_irq, Addr => cpu_addr(0), Datain => cpu_data_out, DataOut => acia_data_out, RxC => acia_clk, TxC => acia_clk, RxD => rxd, TxD => txd, DCD_n => dcd_n, CTS_n => cts_n, RTS_n => rts_n ); my_ACIA_Clock : ACIA_Clock generic map( SYS_Clock_Frequency => SYS_Clock_Frequency, ACIA_Clock_Frequency => ACIA_Clock_Frequency ) port map( clk => Clk_i, acia_clk => acia_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 => ps2_clk, kbd_data => ps2_dat ); ---------------------------------------- -- -- 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_o, vga_green_o => vga_green_o, vga_blue_o => vga_blue_o, vga_hsync_o => vga_hsync_n, vga_vsync_o => vga_vsync_n ); ---------------------------------------- -- -- 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 ); ---------------------------------------- -- -- Bus Trap Interrupt logic -- ---------------------------------------- my_trap : trap port map ( clk => cpu_clk, rst => cpu_reset, 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 ); 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) ); ------------------------------------------------------------------------ -- Instantiate the SDRAM controller that connects to the memory tester -- module and interfaces to the external SDRAM chip. ------------------------------------------------------------------------ u1 : xsaSDRAMCntl generic map( FREQ => FREQ, PIPE_EN => PIPE_EN, DATA_WIDTH => DATA_WIDTH, MULTIPLE_ACTIVE_ROWS => MULTIPLE_ACTIVE_ROWS, NROWS => NROWS, NCOLS => NCOLS, HADDR_WIDTH => HADDR_WIDTH, SADDR_WIDTH => SADDR_WIDTH ) port map( -- Host Side clk => CLKA, -- master clock from external clock source (unbuffered) bufclk => open, -- buffered master clock output clk1x => clk_i, -- synchronized master clock (accounts for delays to external SDRAM) clk2x => open, -- synchronized doubled master clock lock => lock, -- DLL lock indicator rst => rst_i, -- reset rd => hRd, -- host-side SDRAM read control from memory tester wr => hWr, -- host-side SDRAM write control from memory tester rdPending => rdPending,-- read operation to SDRAM is in progress opBegun => opBegun, -- indicates memory read/write has begun earlyOpBegun => earlyBegun, -- early indicator that memory operation has begun rdDone => rdDone, -- indicates SDRAM memory read operation is done done => ramDone, -- indicates SDRAM memory read or write operation is done hAddr => hAddr, -- host-side address from memory tester to SDRAM hDIn => hDIn, -- test data pattern from memory tester to SDRAM hDOut => hDOut, -- SDRAM data output to memory tester status => open, -- SDRAM controller state (for diagnostics) -- SDRAM Side sclkfb => SDRAM_clkfb, -- clock feedback with added external PCB delays sclk => SDRAM_clkout, -- synchronized clock to external SDRAM cke => SDRAM_cke, -- SDRAM clock enable cs_n => SDRAM_cs_n, -- SDRAM chip-select ras_n => SDRAM_ras_n, -- SDRAM RAS cas_n => SDRAM_cas_n, -- SDRAM CAS we_n => SDRAM_we_n, -- SDRAM write-enable ba => SDRAM_ba, -- SDRAM bank address sAddr => SDRAM_A, -- SDRAM address sData => SDRAM_D, -- SDRAM databus dqmh => SDRAM_dqmh, -- SDRAM DQMH dqml => SDRAM_dqml -- SDRAM DQML ); cpu_clk_buffer : BUFG port map( i => Clk25, o => cpu_clk ); pix_clk_buffer : BUFG port map( i => Clk25, o => pix_clk ); ---------------------------------------------------------------------- -- -- Process to decode memory map -- ---------------------------------------------------------------------- mem_decode: process( cpu_clk, cpu_addr, cpu_rw, cpu_vma, dat_addr, rom_data_out, flex_data_out, acia_data_out, keyboard_data_out, vdu_data_out, pb_data_out, timer_data_out, trap_data_out, ram_data_out ) begin cpu_data_in <= (others=>'0'); dat_cs <= '0'; rom_cs <= '0'; flex_cs <= '0'; acia_cs <= '0'; keyboard_cs <= '0'; vdu_cs <= '0'; timer_cs <= '0'; trap_cs <= '0'; pb_cs <= '0'; ide_cs <= '0'; ether_cs <= '0'; slot1_cs <= '0'; slot2_cs <= '0'; ram_cs <= '0'; if cpu_addr( 15 downto 8 ) = "11111111" then cpu_data_in <= rom_data_out; dat_cs <= cpu_vma; -- write DAT rom_cs <= cpu_vma; -- read ROM -- -- Sys09Bug Monitor ROM $F000 - $FFFF -- elsif dat_addr(3 downto 0) = "1111" then -- $XF000 - $XFFFF cpu_data_in <= rom_data_out; rom_cs <= cpu_vma; -- -- IO Devices $E000 - $E7FF -- elsif dat_addr(3 downto 0) = "1110" then -- $XE000 - $XEFFF case cpu_addr(11 downto 8) is -- -- SWTPC peripherals from $E000 to $E0FF -- when "0000" => case cpu_addr(7 downto 4) is -- -- Console Port ACIA $E000 - $E00F -- when "0000" => -- $E000 cpu_data_in <= acia_data_out; acia_cs <= cpu_vma; -- -- Reserved -- Floppy Disk Controller port $E010 - $E01F -- -- -- Keyboard port $E020 - $E02F -- when "0010" => -- $E020 cpu_data_in <= keyboard_data_out; keyboard_cs <= cpu_vma; -- -- VDU port $E030 - $E03F -- when "0011" => -- $E030 cpu_data_in <= vdu_data_out; vdu_cs <= cpu_vma; -- -- Reserved SWTPc MP-T Timer $E040 - $E04F -- when "0100" => -- $E040 cpu_data_in <= (others=> '0'); -- -- Timer $E050 - $E05F -- when "0101" => -- $E050 cpu_data_in <= timer_data_out; timer_cs <= cpu_vma; -- -- Bus Trap Logic $E060 - $E06F -- when "0110" => -- $E060 cpu_data_in <= trap_data_out; trap_cs <= cpu_vma; -- -- Reserved SWTPc MP-ID PIA Timer/Printer Port $E080 - $E08F -- -- -- Reserved SWTPc MP-ID PTM 6840 Timer Port $E090 - $E09F -- -- -- Remaining 6 slots reserved for non SWTPc Peripherals -- when others => -- $E0A0 to $E0FF null; end case; -- -- XST-3.0 Peripheral Bus goes here -- $E100 to $E1FF -- Four devices -- IDE, Ethernet, Slot1, Slot2 -- when "0001" => cpu_data_in <= pb_data_out; pb_cs <= cpu_vma; case cpu_addr(7 downto 6) is -- -- IDE Interface $E100 to $E13F -- when "00" => ide_cs <= cpu_vma; -- -- Ethernet Interface $E140 to $E17F -- when "01" => ether_cs <= cpu_vma; -- -- Slot 1 Interface $E180 to $E1BF -- when "10" => slot1_cs <= cpu_vma; -- -- Slot 2 Interface $E1C0 to $E1FF -- when "11" => slot2_cs <= cpu_vma; -- -- Nothing else -- when others => null; end case; -- -- $E200 to $EFFF reserved for future use -- when others => null; end case; -- -- Flex RAM $0C000 - $0DFFF -- elsif dat_addr(7 downto 1) = "0000110" then -- $0C000 - $0DFFF cpu_data_in <= flex_data_out; flex_cs <= cpu_vma; -- -- Everything else is RAM -- else cpu_data_in <= ram_data_out; ram_cs <= cpu_vma; end if; end process; -- -- 16-bit Peripheral Bus -- 6809 Big endian -- ISA bus little endian -- Not sure about IDE interface -- peripheral_bus: process( clk_i, cpu_reset, cpu_rw, cpu_addr, cpu_data_out ) begin pb_wru <= pb_cs and (not cpu_rw) and (not cpu_addr(0)); pb_wrl <= pb_cs and (not cpu_rw) and cpu_addr(0) ; pb_rdu <= pb_cs and cpu_rw and (not cpu_addr(0)); pb_rdl <= pb_cs and cpu_rw and cpu_addr(0) ; pb_a <= cpu_addr(5 downto 1); -- -- Register upper byte from CPU on first CPU write -- and lower byte from the peripheral bus on first CPU read -- if cpu_reset = '1' then pb_wreg <= (others => '0'); pb_rreg <= (others => '0'); elsif clk_i'event and clk_i ='1' then if pb_wru = '1' then pb_wreg <= cpu_data_out; end if; if pb_rdu = '1' then pb_rreg <= pb_d(7 downto 0); end if; end if; -- -- Peripheral bus read and write strobes are -- Syncronized with the 50 MHz clock -- and are asserted until the peripheral bus hold is released -- if cpu_reset = '1' then pb_wr_n <= '1'; pb_rd_n <= '1'; elsif clk_i'event and clk_i ='1' then if pb_hold = '1' then pb_wr_n <= not pb_wrl; pb_rd_n <= not pb_rdu; else pb_wr_n <= '1'; pb_rd_n <= '1'; end if; end if; -- -- The peripheral bus will be an output -- the registered even byte on data(15 downto 8) -- and the CPU odd bytes on data(7 downto 0) -- on odd byte writes -- if pb_wrl = '1' then pb_d <= pb_wreg & cpu_data_out; else pb_d <= (others => 'Z'); end if; -- -- On even byte reads, -- the CPU reads the low (even) byte of the peripheral bus -- On odd byte reads, -- the CPU reads the registered (odd byte) input from the peripheral bus -- if pb_rdu = '1' then pb_data_out <= pb_d(15 downto 8); elsif pb_rdl = '1' then pb_data_out <= pb_rreg; else pb_data_out <= (others => '0'); end if; end process; -- -- Hold Peripheral bus accesses for a few cycles -- peripheral_bus_hold: process( cpu_clk, cpu_reset, pb_rdu, pb_wrl, ether_rdy ) begin if cpu_reset = '1' then pb_release <= '0'; pb_count <= "0000"; pb_hold_state <= hold_release_state; elsif cpu_clk'event and cpu_clk='1' then -- -- The perpheral bus hold signal should be generated on -- 16 bit bus read which will be on even byte reads or -- 16 bit bus write which will be on odd byte writes. -- case pb_hold_state is when hold_release_state => pb_release <= '0'; if (pb_rdu = '1') or (pb_wrl = '1') then pb_count <= "0100"; pb_hold_state <= hold_request_state; elsif (pb_rdl = '1') or (pb_wru = '1') then pb_release <= '1'; pb_hold_state <= hold_release_state; end if; when hold_request_state => if pb_count = "0000" then if ether_rdy = '1' then pb_release <= '1'; pb_hold_state <= hold_release_state; end if; else pb_count <= pb_count - "0001"; end if; when others => null; end case; end if; end process; -- -- Compact Flash Control -- compact_flash: process( ide_cs, cpu_addr ) begin ide_cs0_n <= not( ide_cs ) or cpu_addr(4); ide_cs1_n <= not( ide_cs and cpu_addr(4)); ide_dmack_n <= '1'; end process; -- -- Interrupts and other bus control signals -- interrupts : process( lock, rst_n, nmi_n, pb_cs, pb_hold, pb_release, ram_cs, ram_hold, ether_irq, acia_irq, keyboard_irq, trap_irq, timer_irq ) begin cpu_reset <= (not rst_n) or (not lock); -- CPU reset is active high pb_hold <= pb_cs and (not pb_release); cpu_irq <= acia_irq or keyboard_irq; cpu_nmi <= trap_irq or not( nmi_n ); cpu_firq <= timer_irq; cpu_halt <= '0'; cpu_hold <= pb_hold or ram_hold; end process; -- -- Flash 7 segment LEDS -- my_led_flasher: process( Clk_i, rst_n, CountL ) begin if rst_n = '0' then CountL <= "000000000000000000000000"; elsif(Clk_i'event and Clk_i = '1') then CountL <= CountL + 1; end if; -- S(7 downto 0) <= CountL(23 downto 16); end process; -- -- Generate a 25 MHz Clock from 50 MHz -- my_prescaler : process( Clk_i, clk_count ) begin if Clk_i'event and Clk_i = '1' then clk_count(0) <= not clk_count(0); end if; Clk25 <= clk_count(0); end process; -- -- Push buttons -- my_switch_assignments : process( SW2_N, SW3_N, rst_n ) begin rst_n <= SW2_N; rst_i <= not rst_n; nmi_n <= SW3_N; -- -- Disable Flash memory -- FLASH_CE_N <= '1'; end process; -- -- RS232 signals: -- my_acia_assignments : process( RS232_RXD, RS232_CTS, txd, rts_n ) begin rxd <= RS232_RXD; cts_n <= RS232_CTS; dcd_n <= '0'; RS232_TXD <= txd; RS232_RTS <= rts_n; end process; -- -- Pin assignments for ethernet controller -- my_ethernet_assignments : process( clk_i, cpu_reset, ether_cs ) begin ether_cs_n <= not ether_cs; ether_aen <= not ether_cs; -- Ethernet address enable not ether_bhe_n <= '1'; -- Ethernet bus high enable - 8 bit access only end process; -- -- I/O expansion slot assignments -- my_slot_assignments : process( slot1_cs, slot2_cs) begin slot1_cs_n <= not slot1_cs; slot2_cs_n <= not slot2_cs; end process; -- -- VGA ouputs -- my_vga_assignments : process( vga_red_o, vga_green_o, vga_blue_o ) begin VGA_red(0) <= vga_red_o; VGA_red(1) <= vga_red_o; VGA_red(2) <= vga_red_o; VGA_green(0) <= vga_green_o; VGA_green(1) <= vga_green_o; VGA_green(2) <= vga_green_o; VGA_blue(0) <= vga_blue_o; VGA_blue(1) <= vga_blue_o; VGA_blue(2) <= vga_blue_o; end process; -- -- SDRAM assignments -- my_sdram_assignments : process( cpu_clk, clk_i, cpu_reset, opBegun, rdDone, wrDone, ram_rd_state, ram_wr_state, cpu_addr, dat_addr, cpu_data_out, hDout, ram_cs, cpu_rw, ram_hold ) begin if( cpu_reset = '1' ) then hWr <= '0'; hRd <= '0'; wrDone <= '0'; ram_wr_state <= wr_state0; ram_rd_state <= rd_state0; elsif( clk_i'event and clk_i='0' ) then -- -- read state machine -- case ram_rd_state is when rd_state0 => if (ram_hold = '1') and (cpu_rw = '1') then hRd <= '1'; ram_rd_state <= rd_state1; end if; when rd_state1 => if opBegun = '1' then ram_rd_state <= rd_state2; end if; when rd_state2 => if rdDone = '1' then hRd <= '0'; ram_rd_state <= rd_state3; end if; when rd_state3 => if rdDone = '0' then ram_rd_state <= rd_state0; end if; when others => hRd <= '0'; ram_rd_state <= rd_state0; end case; -- -- Write state machine -- case ram_wr_state is when wr_state0 => if (ram_hold = '1') and (cpu_rw = '0') then hWr <= '1'; wrDone <= '0'; ram_wr_state <= wr_state1; end if; when wr_state1 => if opBegun = '1' then hWr <= '0'; wrDone <= '0'; ram_wr_state <= wr_state2; end if; when wr_state2 => hWr <= '0'; wrDone <= '0'; ram_wr_state <= wr_state3; when wr_state3 => hWr <= '0'; wrDone <= '1'; ram_wr_state <= wr_state4; when wr_state4 => hWr <= '0'; wrDone <= '0'; ram_wr_state <= wr_state0; when others => hWr <= '0'; wrDone <= '0'; ram_wr_state <= wr_state0; end case; end if; -- -- Strobe host RD and WR signals high on RAM select -- Return low when cycle has started -- if( cpu_reset = '1' ) then ram_hold <= '0'; elsif( cpu_clk'event and cpu_clk='1' ) then -- -- Hold is intitiated when the RAM is selected -- and released when access cycle is complete -- if (ram_hold = '0') and (ram_cs = '1') then ram_hold <= '1'; elsif (ram_hold = '1') and ((rdDone = '1') or (wrDone = '1')) then ram_hold <= '0'; end if; end if; hAddr(23 downto 20) <= "0000"; hAddr(19 downto 12) <= dat_addr; hAddr(11 downto 0) <= cpu_addr(11 downto 0); hDin(7 downto 0) <= cpu_data_out; hDin(15 downto 8) <= (others => '0'); ram_data_out <= hDout(7 downto 0); end process; end rtl; --===================== End of architecture =======================--
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