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[/] [System09/] [trunk/] [rtl/] [System09_Trenz_TE0141/] [System09_Trenz_TE0141.vhd] - Rev 134
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-- SECD Front End Processor derived from System09 written by John E. Kent -- This core adheres to the GNU public license 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; --use config.all; entity System09_trenz is port( -- the following output assignments are required so that -- the GT3200 USB phy generates a 30 MHz clock utmi_databus16_8 : out std_logic; utmi_reset : out std_logic; utmi_xcvrselect : out std_logic; utmi_termselect : out std_logic; utmi_opmode1 : out std_logic; utmi_txvalid : out std_logic; -- this is the 30 MHz clock input (clkout is the utmi name) utmi_clkout : in std_logic; reset_sw : in Std_logic; -- Master Reset input (active low) -- PS/2 Keyboard ps2_clk1 : inout Std_logic; ps2_data1 : inout Std_Logic; -- acia Interface fpga_rxd : in Std_Logic; fpga_txd : out Std_Logic; fpga_cts : in Std_Logic; fpga_rts : out Std_Logic; -- CRTC output signals vsync_b : out Std_Logic; hsync_b : out Std_Logic; fpga_b : out Std_Logic_Vector(2 downto 0); fpga_g : out Std_Logic_Vector(2 downto 0); fpga_r : out Std_Logic_Vector(2 downto 0); -- LEDS & Switches mm_led : out Std_Logic; led : out Std_Logic_Vector(3 downto 0); joy_down : in Std_Logic; joy_fire : in Std_Logic; joy_left : in Std_Logic; joy_right : in Std_Logic; joy_up : in Std_Logic; -- LCD Display lcd_e : out Std_Logic; lcd_rw : out Std_Logic; lcd_rs : out Std_Logic; lcd_d : inout Std_Logic_Vector(3 downto 0); -- Audio aud_out : out std_logic_vector(4 downto 1); --ir remote control ir_data : in std_logic; -- Memory interface ram_a : out std_logic_vector(20 downto 0); ram_io : inout std_logic_vector(15 downto 0); ram_bhen : out std_logic; ram_blen : out std_logic; ram_cen : out std_logic; ram_oen : out std_logic; ram_wen : out std_logic; -- Flash interface fl_resetn : out std_logic; fl_cen : out std_logic; fl_oen : out std_logic; fl_byten : out std_logic; fl_busyn : in std_logic; -- Compact flash cf_we : out std_logic; -- all these signals are active low cf_reg : out std_logic; -- for more details see the specification cf_cs0 : out std_logic; -- of compact flash cf_cs1 : out std_logic; cf_reset : out std_logic; cf_iord : out std_logic; cf_iowr : out std_logic; cf_irq : in std_logic; cf_wait : in std_logic; cf_cd1 : in std_logic; cf_cd2 : in std_logic; iois16 : in std_logic; cf_oe : out std_logic; cf_dasp : inout std_logic; cf_pdiag : inout std_logic; --cf power enable (active low) cf_pwr_en : out std_logic ); end System09_trenz; ------------------------------------------------------------------------------- -- Architecture for System09 ------------------------------------------------------------------------------- architecture rtl of System09_trenz is ----------------------------------------------------------------------------- -- constants ----------------------------------------------------------------------------- constant SYS_Clock_Frequency : integer := 50_000_000; -- FPGA System Clock constant VGA_Clock_Frequency : integer := 25_000_000; -- VGA Pixel Clock constant CPU_Clock_Frequency : integer := 25_000_000; -- 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 ); ----------------------------------------------------------------------------- -- ChipScope Pro components and signals ----------------------------------------------------------------------------- -- component icon -- port(control0 : out std_logic_vector(35 downto 0)); -- end component; -- component ila -- port(control : in std_logic_vector(35 downto 0); -- clk : in std_logic; -- trig0 : in std_logic_vector(39 downto 0)); -- end component; -- signal chipscope_control : std_logic_vector(35 downto 0); -- signal ila_clock : std_logic; ----------------------------------------------------------------------------- -- Signals ----------------------------------------------------------------------------- -- Clocks attribute buffer_type : string; attribute period : string; signal sys_clk : std_logic; -- 50 Mhz attribute period of sys_clk : signal is "20 ns"; attribute buffer_type of sys_clk : signal is "BUFG"; signal cpu_clk : std_logic; -- 25 Mhz attribute period of cpu_clk : signal is "40 ns"; attribute buffer_type of cpu_clk : signal is "BUFG"; signal vga_clk : std_logic; -- 25 Mhz attribute period of vga_clk : signal is "40 ns"; attribute buffer_type of vga_clk : signal is "BUFG"; -- System Reset (generated by key press) signal cpu_reset : std_logic; -- Dynamic Address Translation signal dat_cs : std_logic; signal dat_addr : std_logic_vector(7 downto 0); -- BOOT ROM signal rom_cs : Std_logic; signal rom_data_out : Std_Logic_Vector(7 downto 0); -- FLEX9 RAM signal flex_cs : Std_logic; signal flex_data_out : Std_Logic_Vector(7 downto 0); -- acia Interface signals signal acia_data_out : Std_Logic_Vector(7 downto 0); signal acia_cs : Std_Logic; signal acia_irq : Std_Logic; signal baudclk : 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; -- CPU Interface signals 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); -- Compact Flash port -- CF data bus shared with RAM -- signal cf_data_out : std_logic_vector(7 downto 0); signal cf_cs0x : std_logic; signal cf_cs1x : 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; -- Video Display Unit signal vdu_cs : std_logic; signal vdu_data_out : std_logic_vector(7 downto 0); -- VGA output signals (distributed to VGA DAC) signal red : std_logic; signal green : std_logic; signal blue : std_logic; -- LCD register select signal lcd_cs : std_logic; signal lcd_data_in : std_logic_vector(7 downto 0); signal lcd_data_out : std_logic_vector(7 downto 0); -- LED register select signal leds_cs : std_logic; signal leds_data_in : std_logic_vector(7 downto 0) := (others => '0'); signal leds_data_out : std_logic_vector(7 downto 0) := (others => '0'); -- Joystick buffer signal joy_cs : std_logic; signal joy_data_out : std_logic_vector(7 downto 0); -- External RAM interface signal ram_cs : std_logic := '0'; signal ram_data_out : std_logic_vector(7 downto 0); signal ram_oe : std_logic; signal ram_we : std_logic; -- Locked signal of clock synthesizer signal clock_locked : std_logic; signal ila_clock : std_logic; -- LED Flasher signal blink_count : std_logic_vector(25 downto 0) := (others => '0'); -- System Clock Prescaler signal clk_count : 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; ---------------------------------------- -- -- 4KByte 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; ---------------------------------------- -- -- 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; -- ACIA 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 := VGA_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 ram_controller -- port( -- reset : in std_logic; -- clk : in std_logic; -- cs_ram : in std_logic; -- rw : in std_logic; -- din : in std_logic_vector(7 downto 0); -- dout : out std_logic_vector(7 downto 0); -- addr : in std_logic_vector(19 downto 0); -- External interface -- ram_oen : out std_logic; -- ram_cen : out std_logic; -- ram_wen : out std_logic; -- ram_io : inout std_logic_vector(15 downto 0); -- ram_a : out std_logic_vector(20 downto 1); -- ram_bhen : out std_logic; -- ram_blen : out std_logic -- ); -- end component; component BUFG port ( i : in std_logic; o : out std_logic ); end component; begin ----------------------------------------------------------------- -- -- ChipsScope Pro cores -- ----------------------------------------------------------------- -- i_icon : icon -- port map(control0 => chipscope_control); -- -- i_ila : ila -- port map(control => chipscope_control, -- clk => ila_clock, -- trig0(15 downto 8) => cpu_data_in, -- trig0(23 downto 16) => cpu_data_out, -- trig0(39 downto 24) => cpu_addr, -- trig0(0) => cpu_clk, -- trig0(1) => cpu_vma, -- trig0(2) => ram_bhenx, -- trig0(3) => ram_blenx, -- trig0(4) => ram_cenx, -- trig0(5) => ram_oenx, -- trig0(6) => ram_wenx, -- trig0(7) => vga_clk); ----------------------------------------------------------------- -- -- CPU09 CPU core -- ----------------------------------------------------------------- my_cpu : entity cpu09 port map ( clk => cpu_clk, rst => cpu_reset, rw => cpu_rw, vma => cpu_vma, address => cpu_addr, 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 ); ---------------------------------------- -- -- Sys09Bug ROM (Xilinx Block RAM, 4k) -- ---------------------------------------- my_rom : mon_rom port map ( clk => cpu_clk, rst => cpu_reset, cs => rom_cs, rw => '1', addr => cpu_addr(11 downto 0), rdata => rom_data_out, wdata => cpu_data_out ); ---------------------------------------- -- -- Flex Operating System (Xilinx Block RAM, 8k) -- ---------------------------------------- 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 ); ---------------------------------------- -- -- Dynamic Address Translation -- ---------------------------------------- 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) ); ----------------------------------------------------------------- -- -- 6850 ACIA -- ----------------------------------------------------------------- my_acia : entity 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 => baudclk, TxC => baudclk, RxD => fpga_rxd, TxD => fpga_txd, DCD_n => dcd_n, CTS_n => fpga_cts, RTS_n => fpga_rts ); ---------------------------------------- -- -- 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_clk1, kbd_data => ps2_data1 ); ---------------------------------------- -- -- Video Display Unit instantiation -- ---------------------------------------- my_vdu : vdu8 generic map( VDU_CLOCK_FREQUENCY => CPU_Clock_Frequency, -- HZ VGA_CLOCK_FREQUENCY => VGA_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 => vga_clk, -- 25 MHz VDU pixel clock vga_red_o => red, vga_green_o => green, vga_blue_o => blue, vga_hsync_o => hsync_b, vga_vsync_o => vsync_b ); ---------------------------------------- -- -- Clock Synthesis instantiation -- ---------------------------------------- my_clock_synthesis : entity clock_synthesis port map ( clk_30mhz => utmi_clkout, sys_clk_out => sys_clk, locked => clock_locked ); vga_clk_buffer : BUFG port map( i => clk_count, o => vga_clk ); cpu_clk_buffer : BUFG port map( i => clk_count, o => cpu_clk ); ---------------------------------------- -- -- RAM Controller instantiation -- ---------------------------------------- -- my_external_ram : entity ram_controller port map ( -- reset => cpu_reset, -- clk => cpu_clk, -- cs_ram => ram_cs, -- rw => cpu_rw, -- din => cpu_data_out, -- dout => ram_data_out, -- addr(19 downto 12) => dat_addr( 7 downto 0), -- addr(11 downto 0) => cpu_addr(11 downto 0), -- external interface -- ram_oen => ram_oenx, -- ram_cen => ram_cenx, -- ram_wen => ram_wenx, -- ram_io => ram_io, -- ram_a => ram_a, -- ram_bhen => ram_bhenx, -- ram_blen => ram_blenx -- ); ---------------------------------------- -- -- ACIA Clock -- ---------------------------------------- my_ACIA_Clock : ACIA_Clock generic map( SYS_Clock_Frequency => SYS_Clock_Frequency, ACIA_Clock_Frequency => ACIA_Clock_Frequency ) port map( clk => sys_clk, acia_clk => baudclk ); -- -- Generate a 25 MHz Clock from 50 MHz -- my_sys09_clk : process( sys_clk, clk_count ) begin if sys_clk'event and sys_clk = '1' then clk_count <= not clk_count; end if; end process; ---------------------------------------------------------------------- -- -- Process to decode memory map -- ---------------------------------------------------------------------- mem_decode: process( cpu_addr, cpu_rw, cpu_vma, dat_cs, dat_addr, rom_data_out, acia_data_out, keyboard_data_out, vdu_data_out, joy_data_out, lcd_data_out, leds_data_out, flex_data_out, ram_data_out ) begin cpu_data_in <= (others => '0'); dat_cs <= '0'; rom_cs <= '0'; acia_cs <= '0'; keyboard_cs <= '0'; vdu_cs <= '0'; cf_cs0x <= '0'; cf_cs1x <= '0'; joy_cs <= '0'; lcd_cs <= '0'; leds_cs <= '0'; flex_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 -- -- Monitor ROM $F000 - $FFFF -- cpu_data_in <= rom_data_out; rom_cs <= cpu_vma; -- read ROM -- -- IO Devices $E000 - $EFFF -- elsif dat_addr(3 downto 0) = "1110" then -- $XE000 - $XEFFF dat_cs <= '0'; rom_cs <= '0'; case cpu_addr(11 downto 8) is when "0000" => case cpu_addr(7 downto 4) is -- -- UART / ACIA ($E000 - $E00F) -- when "0000" => cpu_data_in <= acia_data_out; acia_cs <= cpu_vma; -- -- Reserved - FD1771 FDC ($E010 - $E01F) (SWTPC) -- -- -- Keyboard port ($E020 - $E02F) -- when "0010" => cpu_data_in <= keyboard_data_out; keyboard_cs <= cpu_vma; -- -- VDU port ($E030 - $E03F) -- when "0011" => cpu_data_in <= vdu_data_out; vdu_cs <= cpu_vma; -- -- Reserved SWTPc MP-T ($E040 - $E04F) -- -- -- Reserved - Timer ($E050 - $E05F) (B5-X300) -- -- -- Reserved - Bus Trap Logic ($E060 - $E06F) (B5-X300) -- -- -- Reserved - I/O port ($E070 - $E07F) (B5-X300) -- -- -- Reserved - PTM 6840 ($E080 - $E08F) (SWTPC) -- -- -- Reserved - PIA Timer ($E090 - $E09F) (SWTPC) -- -- -- Read LED port ($E0A0 - $E0AF) -- Write LEDS -- when "1010" => cpu_data_in <= leds_data_out; leds_cs <= cpu_vma; -- -- LCD display port ($E0B0 - $E0BF) -- when "1011" => cpu_data_in <= lcd_data_out; lcd_cs <= cpu_vma; -- -- Read Joy Stick port ($E0D0 - $E0DF) -- Write LEDS -- when "1101" => cpu_data_in <= joy_data_out; joy_cs <= cpu_vma; -- -- Read LED port ($E0E0 - $E0EF) -- Write LEDS -- when "1110" => cpu_data_in <= leds_data_out; leds_cs <= cpu_vma; -- -- LCD display port ($E0F0 - $E0BF) -- when "1111" => cpu_data_in <= lcd_data_out; lcd_cs <= cpu_vma; when others => -- $EXC0 to $EXFF null; end case; -- -- XST-3.0 Peripheral Bus goes here -- $E100 to $E1FF -- Four devices -- IDE, Ethernet, Slot1, Slot2 -- when "0001" => cpu_data_in <= ram_data_out; case cpu_addr(7 downto 4) is -- -- CF Interface $E100 to $E1FF -- when "0000" => cf_cs0x <= cpu_vma; when "0001" => cf_cs1x <= cpu_vma; -- -- Nothing else -- when others => null; end case; -- -- $E200 to $EFFF reserved for future use -- when others => cpu_data_in <= (others => '0'); 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; -- -- 1M byte SRAM Control -- Processes to read and write memory based on bus signals -- using bhe/ble controlled read and write. -- Can't gate the write pulse with the clock -- because the bus is shared with the CF -- which uses clock stretching. -- ram_process: process( cpu_reset, sys_clk, cpu_addr, cpu_rw, cpu_data_out, dat_addr, ram_cs, ram_io, ram_we, ram_oe ) begin -- -- ram_hold signal helps -- if( cpu_reset = '1' ) then ram_we <= '0'; ram_oe <= '0'; -- -- Clock Hold on rising edge -- elsif( sys_clk'event and sys_clk='1' ) then if (ram_cs = '1') and (ram_we = '0') and (ram_oe = '0') then ram_we <= not cpu_rw; ram_oe <= cpu_rw; else ram_we <= '0'; ram_oe <= '0'; end if; end if; ram_cen <= not ram_cs; ram_bhen <= cpu_addr(0); ram_blen <= not cpu_addr(0); ram_wen <= not ram_we; ram_oen <= not ram_oe; ram_a(20) <= '0'; ram_a(19 downto 0) <= dat_addr(7 downto 0) & cpu_addr(11 downto 0); if (cpu_rw = '0') and (cpu_addr(0) = '0') then ram_io(15 downto 8) <= cpu_data_out; else ram_io(15 downto 8) <= "ZZZZZZZZ"; end if; if (cpu_rw = '0') and (cpu_addr(0) = '1') then ram_io(7 downto 0) <= cpu_data_out; else ram_io(7 downto 0) <= "ZZZZZZZZ"; end if; if cpu_addr(0) = '0' then ram_data_out <= ram_io(15 downto 8); else ram_data_out <= ram_io(7 downto 0); end if; end process; -- -- Compact Flash Control -- Configure compact flash for TRUE IDE mode -- compact_flash: process( reset_sw, cpu_addr, cpu_rw, cpu_vma, cpu_data_out, cf_cs0x, cf_cs1x, cf_rd, cf_wr, cf_cd1, cf_cd2 ) begin cf_reset <= reset_sw; cf_pwr_en <= (cf_cd1) or (cf_cd2); -- power enable when card detect cf_oe <= '0'; -- TRUE IDE mode cf_we <= '1'; cf_reg <= '1'; cf_cs0 <= not cf_cs0x; cf_cs1 <= not cf_cs1x; cf_wr <= (cf_cs0x or cf_cs1x) and (not cpu_rw); cf_rd <= (cf_cs0x or cf_cs1x) and cpu_rw; cf_iowr <= not cf_wr; cf_iord <= not cf_rd; end process; -- -- Hold CF access for a few cycles -- cf_hold_proc: process( cpu_clk, cpu_reset ) begin if cpu_reset = '1' then cf_release <= '0'; cf_count <= "0000"; cf_hold_state <= hold_release_state; elsif falling_edge( cpu_clk ) then case cf_hold_state is when hold_release_state => cf_release <= '0'; if (cf_cs0x = '1') or (cf_cs1x = '1') then cf_count <= "0011"; cf_hold_state <= hold_request_state; end if; when hold_request_state => cf_count <= cf_count - "0001"; if cf_count = "0000" then cf_release <= '1'; cf_hold_state <= hold_release_state; end if; when others => null; end case; end if; end process; -- -- Interrupts and other bus control signals -- interrupts : process( acia_irq, keyboard_irq, joy_up, cf_cs0x, cf_cs1x, cf_hold, cf_release ) begin cf_hold <= (cf_cs0x or cf_cs1x) and (not cf_release); cpu_irq <= keyboard_irq; cpu_nmi <= not joy_up; cpu_firq <= acia_irq; cpu_halt <= '0'; cpu_hold <= cf_hold; end process; -- -- LCD write register -- LCD_data_in and LCD_data_out -- are relative to the CPU -- Not the LCD display -- lcd_control : process(cpu_reset, cpu_clk, lcd_data_in, lcd_d ) begin if cpu_reset = '1' then lcd_data_in <= (others => '0'); elsif falling_edge(cpu_clk) then if lcd_cs = '1' and cpu_rw = '0' then lcd_data_in <= cpu_data_out; end if; end if; if lcd_data_in(4) = '1' and lcd_data_in(5) = '0' then lcd_d <= lcd_data_in(3 downto 0); else lcd_d <= (others => 'Z'); end if; lcd_e <= lcd_data_in(4); lcd_rw <= lcd_data_in(5); lcd_rs <= lcd_data_in(6); -- read back control signals lcd_data_out(7 downto 4) <= lcd_data_in(7 downto 4); -- read back 4 bit data bus lcd_data_out(3 downto 0) <= lcd_d(3 downto 0); end process; -- -- LED write register -- led_control : process(cpu_reset, cpu_clk, leds_data_in) begin if cpu_reset = '1' then leds_data_in <= (others => '1'); elsif falling_edge(cpu_clk) then if leds_cs = '1' and cpu_rw = '0' then leds_data_in <= cpu_data_out; end if; end if; led <= leds_data_in(3 downto 0); -- read back output state leds_data_out <= leds_data_in; end process; -- -- Joystick register -- read_joystick : process(cpu_clk, joy_up, joy_right, joy_down, joy_left, joy_fire) begin if rising_edge(cpu_clk) then joy_data_out(0) <= joy_up; joy_data_out(1) <= joy_right; joy_data_out(2) <= joy_down; joy_data_out(3) <= joy_left; joy_data_out(4) <= joy_fire; joy_data_out(7 downto 5) <= (others => '0'); end if; end process; -- -- LED Flasher -- my_led_flasher: process(vga_clk, cpu_reset, blink_count) begin if cpu_reset = '1' then blink_count <= (others => '0'); elsif rising_edge(vga_clk) then blink_count <= blink_count + 1; end if; mm_led <= blink_count(25); end process; -- Set acia DCD to always true DCD_n <= '0'; -- -- configure utmi for 30MHz clock -- utmi_databus16_8 <= '1'; utmi_reset <= '0'; utmi_xcvrselect <= '1'; utmi_termselect <= '1'; utmi_opmode1 <= '0'; utmi_txvalid <= '0'; -- -- Feed RGB DAC -- fpga_r(0) <= red; fpga_r(1) <= red; fpga_r(2) <= red; fpga_g(0) <= green; fpga_g(1) <= green; fpga_g(2) <= green; fpga_b(0) <= blue; fpga_b(1) <= blue; fpga_b(2) <= blue; -- Hold system in reset until the clock is locked or when the reset -- key is pressed. cpu_reset <= (not reset_sw ) or (not clock_locked); -- -- Terminate Audio Output signals -- aud_out <= (others => '0'); -- -- Terminate Flash memory controls -- fl_resetn <= '1'; fl_cen <= '1'; fl_oen <= '1'; fl_byten <= '1'; -- debug output -- input detected from an IR remote control is forwarded to the LED on the micromodule. -- there it is easily accessible by a scope and you can also see some flicker when pressing a button. -- mm_led <= ir_data; end;
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