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keymapper.vhdl
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keymapper.vhdl
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library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use ieee.numeric_std.all;
use Std.TextIO.all;
use work.debugtools.all;
entity keymapper is
port (
pixelclk : in std_logic;
cpu_hypervisor_mode : in std_logic;
drive_led_out : in std_logic;
last_scan_code : out std_logic_vector(12 downto 0);
nmi : out std_logic := 'Z';
reset : out std_logic := 'Z';
hyper_trap : out std_logic := '1';
hyper_trap_count : out unsigned(7 downto 0) := x"00";
-- USE ASC/DIN / CAPS LOCK key to control CPU speed instead of CAPS LOCK function
speed_gate : out std_logic := '1';
speed_gate_enable : in std_logic := '1';
-- appears as bit0 of $D607 (see C65 keyboard scan routine at $E406)
capslock_out : out std_logic := '1';
-- PS2 keyboard interface
ps2clock : in std_logic;
ps2data : in std_logic;
-- CIA ports
porta_in : in std_logic_vector(7 downto 0);
portb_in : in std_logic_vector(7 downto 0);
porta_out : out std_logic_vector(7 downto 0);
portb_out : out std_logic_vector(7 downto 0);
pota_x : out unsigned(7 downto 0) := x"ff";
pota_y : out unsigned(7 downto 0) := x"ff";
potb_x : out unsigned(7 downto 0) := x"ff";
potb_y : out unsigned(7 downto 0) := x"ff";
-- read from bit1 of $D607 (see C65 keyboard scan routine at $E406)?
keyboard_column8_select_in : in std_logic;
pmod_clock : in std_logic;
pmod_start_of_sequence : in std_logic;
pmod_data_in : in std_logic_vector(3 downto 0);
pmod_data_out : out std_logic_vector(1 downto 0) := "ZZ";
-- ethernet keyboard input interface for remote head mode
eth_keycode_toggle : in std_logic;
eth_keycode : in unsigned(15 downto 0)
);
end entity keymapper;
architecture behavioural of keymapper is
type ps2_state is (Idle,StartBit,Bit0,Bit1,Bit2,Bit3,Bit4,Bit5,Bit6,Bit7,
ParityBit,StopBit);
signal ps2state : ps2_state := Idle;
signal resetbutton_state : std_logic := 'Z';
signal matrix_offset : integer range 0 to 255 := 252;
signal last_pmod_clock : std_logic := '1';
signal scan_code : unsigned(7 downto 0) := x"FF";
signal parity : std_logic := '0';
-- PS2 clock rate is as low as 10KHz. Allow double that for a timeout
-- 192MHz/5KHz = 192000/5 = 38400 cycles
-- 48MHz/5khz = 48000/5 = 9600 cycles
constant ps2timeout : integer := 9600;
signal ps2timer : integer range 0 to ps2timeout := 0;
signal hyper_trap_count_internal : unsigned(7 downto 0) := x"00";
signal ps2clock_samples : std_logic_vector(7 downto 0) := (others => '1');
signal ps2clock_debounced : std_logic := '0';
signal ps2data_samples : std_logic_vector(7 downto 0) := (others => '1');
signal ps2data_debounced : std_logic := '0';
signal ps2clock_prev : std_logic := '0';
signal recent_scan_code_list_index : unsigned(7 downto 0) := x"01";
signal extended : std_logic := '0';
signal break : std_logic := '0';
signal matrix : std_logic_vector(71 downto 0) := (others =>'1');
signal joy1 : std_logic_vector(4 downto 0) := (others =>'1');
signal joy2 : std_logic_vector(4 downto 0) := (others =>'1');
signal restore_state : std_logic := '1';
signal restore_event : std_logic := '0';
signal restore_down_ticks : unsigned(7 downto 0) := (others => '0');
signal restore_up_ticks : unsigned(7 downto 0) := (others => '0');
signal fiftyhz_counter : unsigned(7 downto 0) := (others => '0');
signal reset_drive : std_logic;
signal eth_keycode_toggle_last : std_logic := '0';
signal ethernet_keyevent : std_logic := '0';
begin -- behavioural
-- purpose: read from ps2 keyboard interface
keyread: process (pixelclk, ps2data,ps2clock)
variable full_scan_code : std_logic_vector(11 downto 0);
variable portb_value : std_logic_vector(7 downto 0);
variable porta_value : std_logic_vector(7 downto 0);
begin -- process keyread
if rising_edge(pixelclk) then
reset <= reset_drive;
-------------------------------------------------------------------------
-- Generate timer for keyscan timeout
-------------------------------------------------------------------------
if ps2timer < ps2timeout then
ps2timer <= ps2timer + 1;
end if;
if ps2timer >= ps2timeout then
-- Reset ps2 keyboard timer
ps2timer <= 0;
ps2state <= Idle;
-- Use this 10KHz loop to divide down to 50 hz to work out how many
-- 50Hz ticks the restore key has been down. If restore is not down,
-- then reset the count to zero.
-- Complementary to this, we also need to know how long RESTORE has
-- been UP, so that we can send the hypervisor trap/freeze signal when
-- RESTORE has been double-tapped.
-- Double-tap restore is detected by DOWN-UP-DOWN signature.
-- We note how long the UP is, and if it is within our acceptable
-- timeframe, then we consider a double-tap to have occurred.
hyper_trap_count <= restore_up_ticks;
if restore_state='0' then
if (restore_up_ticks>=1 and restore_up_ticks<18) then
-- Trap to hypervisor when restore is double-tapped
-- with the second tap occurring after not more than 12/50ths
-- (~240ms)
hyper_trap <= '0';
-- hyper_trap_count <= hyper_trap_count_internal + 1;
-- hyper_trap_count_internal <= hyper_trap_count_internal + 1;
else
hyper_trap <= '1';
end if;
else
hyper_trap <= '1';
end if;
fiftyhz_counter <= fiftyhz_counter + 1;
if fiftyhz_counter = 200 then
fiftyhz_counter <= (others => '0');
if restore_state='0' then
-- Restore key is down
if restore_down_ticks /= x"ff" then
restore_down_ticks <= restore_down_ticks + 1;
end if;
restore_up_ticks <= (others => '0');
else
-- If restore key is not down, reset count of how long it has been
-- down, and release NMI and reset lines in case we were asserting
-- them.
-- NOTE: This approach means that NMI and RESET will be asserted for
-- between 1 cycle and 1/50th of a second. There is a possible problem
-- with reset and NMI being asserted for less than 2 cycles, but
-- this should be extremely rare. We have solved this by resetting
-- fifyhz_counter when the reset key is released.
restore_down_ticks <= (others => '0');
if restore_up_ticks /= x"ff" then
restore_up_ticks <= restore_up_ticks + 1;
end if;
nmi <= 'Z';
reset_drive <= resetbutton_state;
hyper_trap <= '1';
end if;
end if;
end if;
------------------------------------------------------------------------
-- Read from MEGA keyboard/joystick/expansion port PMOD interface
------------------------------------------------------------------------
-- This interface has a clock, start-of-sequence signal and 4 data lines
-- The data is pumped out in the correct order for us to just stash it
-- into the matrix (or, at least it will when it is implemented ;)
last_pmod_clock <= pmod_clock;
if pmod_clock='1' and last_pmod_clock='0' then
-- Data available
if pmod_start_of_sequence='1' then
-- Write first four bits, and set offset for next time
matrix_offset <= 4;
matrix(3 downto 0) <= pmod_data_in;
-- First two bits of output from FPGA to input PCB is the status of
-- the two LEDs: power LED is on when CPU is not in hypervisor mode,
-- drive LED shows F011 drive status.
pmod_data_out(0) <= not cpu_hypervisor_mode;
pmod_data_out(1) <= drive_led_out;
else
-- Clear output bits for bit positions for which we yet have no assignment
pmod_data_out <= "00";
if matrix_offset < 252 then
matrix_offset <= matrix_offset+ 4;
end if;
-- Read keyboard matrix when required
if matrix_offset < 72 then
matrix((matrix_offset +3) downto matrix_offset) <= pmod_data_in;
end if;
-- Joysticks + restore + capslock + reset? (72-79, 80-87)
if matrix_offset = 72 then
-- joy 1 directions
joy1(3 downto 0) <= pmod_data_in;
end if;
if matrix_offset = 76 then
-- restore is active low, like all other keys
restore_state <= pmod_data_in(3);
if speed_gate_enable='1' then
-- CAPS LOCK UP = force 48MHz, down = enable speed control
speed_gate <= not pmod_data_in(2);
capslock_out <= '1';
else
-- CAPS LOCK does CAPS LOCK, and speed control is enabled
speed_gate <= '1';
capslock_out <= pmod_data_in(2);
end if;
joy1(4) <= pmod_data_in(0);
-- Check for RESTORE key being released, and adjust action
-- based on how long it was being held down.
if pmod_data_in(3)='1' and restore_state='0' then
if restore_down_ticks < 25 then
nmi <= '0';
-- But holding it down for >2 seconds does nothing,
-- incase someone holds it by mistake.
elsif restore_down_ticks < 100 then
reset_drive <= '0';
end if;
-- Make sure that next check for releasing NMI
-- and reset is not for almost 1/50th of a second.
fiftyhz_counter <= (others => '0');
end if;
end if;
if matrix_offset = 80 then
-- joy 2 directions
joy2(3 downto 0) <= pmod_data_in;
end if;
if matrix_offset = 84 then
if pmod_data_in(3)='0' then
resetbutton_state <= '0';
else
resetbutton_state <= 'Z';
end if;
joy2(4) <= pmod_data_in(0);
end if;
-- Expansion port state (88-127)
-- Reserved for extra stuff (128-255)
-- 4x 8-bit analog paddle inputs
if matrix_offset = 128 then
pota_x(7 downto 4) <= unsigned(pmod_data_in);
end if;
if matrix_offset = 132 then
pota_x(3 downto 0) <= unsigned(pmod_data_in);
end if;
if matrix_offset = 136 then
pota_y(7 downto 4) <= unsigned(pmod_data_in);
end if;
if matrix_offset = 140 then
pota_y(3 downto 0) <= unsigned(pmod_data_in);
end if;
if matrix_offset = 144 then
potb_x(7 downto 4) <= unsigned(pmod_data_in);
end if;
if matrix_offset = 148 then
potb_x(3 downto 0) <= unsigned(pmod_data_in);
end if;
if matrix_offset = 152 then
potb_y(7 downto 4) <= unsigned(pmod_data_in);
end if;
if matrix_offset = 156 then
potb_y(3 downto 0) <= unsigned(pmod_data_in);
end if;
end if;
end if;
------------------------------------------------------------------------
-- Read from PS/2 keyboard/mouse interface
------------------------------------------------------------------------
ps2clock_samples <= ps2clock_samples(6 downto 0) & ps2clock;
if ps2clock_samples = "11111111" then
ps2clock_debounced <= '1';
end if;
if ps2clock_samples = "00000000" then
ps2clock_debounced <= '0';
end if;
ps2data_samples <= ps2data_samples(6 downto 0) & ps2data;
if ps2data_samples = "11111111" then
ps2data_debounced <= '1';
end if;
if ps2data_samples = "00000000" then
ps2data_debounced <= '0';
end if;
ps2clock_prev <= ps2clock_debounced;
if eth_keycode_toggle /= eth_keycode_toggle_last then
scan_code <= eth_keycode(7 downto 0);
break <= eth_keycode(12);
extended <= eth_keycode(8);
eth_keycode_toggle_last <= eth_keycode_toggle;
-- now rig status so that next cycle the key event will be processed
ps2state <= Bit7;
ethernet_keyevent <= '1';
elsif (ps2clock_debounced = '0' and ps2clock_prev = '1')
or (ethernet_keyevent = '1') then
ethernet_keyevent <= '0';
ps2timer <= 0;
case ps2state is
when Idle => ps2state <= StartBit; scan_code <= x"FF"; parity <= '0';
-- Check for keyboard input via ethernet
when StartBit => ps2state <= Bit0; scan_code(0) <= ps2data_debounced;
parity <= parity xor ps2data_debounced;
when Bit0 => ps2state <= Bit1; scan_code(1) <= ps2data_debounced;
parity <= parity xor ps2data_debounced;
when Bit1 => ps2state <= Bit2; scan_code(2) <= ps2data_debounced;
parity <= parity xor ps2data_debounced;
when Bit2 => ps2state <= Bit3; scan_code(3) <= ps2data_debounced;
parity <= parity xor ps2data_debounced;
when Bit3 => ps2state <= Bit4; scan_code(4) <= ps2data_debounced;
parity <= parity xor ps2data_debounced;
when Bit4 => ps2state <= Bit5; scan_code(5) <= ps2data_debounced;
parity <= parity xor ps2data_debounced;
when Bit5 => ps2state <= Bit6; scan_code(6) <= ps2data_debounced;
parity <= parity xor ps2data_debounced;
when Bit6 => ps2state <= Bit7; scan_code(7) <= ps2data_debounced;
parity <= parity xor ps2data_debounced;
when Bit7 => ps2state <= parityBit;
-- if parity = ps2data then
-- Valid PS2 symbol
-- XXX Make a little FSM to set bit 8 on E0 xx sequences
-- so that we can have a 9-bit number to look up.
-- XXX also work out when a key goes down versus up by F0
-- byte.
if scan_code = x"F0" then
-- break code
break <= '1';
elsif scan_code = x"E0" then
extended <= '1';
else
full_scan_code := "000" & extended & std_logic_vector(scan_code);
break <= '0';
extended <= '0';
report "PS2KEYBOARD: processing scan code $" & to_hstring("000"&break&"000"&extended&std_logic_vector(scan_code));
-- keyboard scancodes for the more normal keys from a keyboard I have here
-- (will replace these with the keyrah obtained ones)
-- $DC01 bits
-- 0 1 2 3 4 5 6 7
-- $DC00 values
-- Bit#0 $FE 1E0 5A 174 83 05 04 03 72
-- Bit#1 $FD 26 1D 1C 25 1A 1B 24 12
-- Bit#2 $FB 2E 2D 23 36 21 2B 2C 22
-- Bit#3 $F7 3D 35 34 3E 32 33 3C 2A
-- Bit#4 $EF 46 43 3B 45 3A 42 44 31
-- Bit#5 $DF 55 4D 4B 4E 49 54 5B 41
-- Bit#6 $BF 52 5D 4C 16C 59 169 75 4A
-- Bit#7 $7F 16 6B 14 1E 29 11 15 76
-- RESTORE - 0E (`/~ key)
-- Let the CPU read the most recent scan code for
-- debugging keyboard layout.
last_scan_code <= break & full_scan_code;
case full_scan_code is
when x"17D" =>
-- Restore key shall do NMI as expected, but also
-- reset
restore_state <= break;
if break='1' then
if restore_down_ticks < 25 then
nmi <= '0';
-- But holding it down for >2 seconds does nothing,
-- incase someone holds it by mistake.
elsif restore_down_ticks < 100 then
reset_drive <= '0';
end if;
-- Make sure that next check for releasing NMI
-- and reset is not for almost 1/50th of a second.
fiftyhz_counter <= (others => '0');
end if;
-- Joysticks
when x"07d" => -- JOY1 LEFT
joy1(0) <= break;
when x"07a" => -- JOY1 RIGHT
joy1(1) <= break;
when x"06c" => -- JOY1 UP
joy1(2) <= break;
when x"069" => -- JOY1 DOWN
joy1(3) <= break;
when x"070" => -- JOY1 FIRE
joy1(4) <= break;
when x"075" => -- JOY2 LEFT
joy2(0) <= break;
when x"074" => -- JOY2 DOWN
joy2(3) <= break;
-- when x"072" => -- JOY2 RIGHT
-- joy2(3) <= break;
when x"06b" => -- JOY2 UP
joy2(2) <= break;
when x"073" => -- JOY2 FIRE
joy2(4) <= break;
-- DELETE, RETURN, RIGHT, F7, F1, F3, F5, down
when x"066" => matrix(0) <= break;
when x"05A" => matrix(1) <= break;
when x"174" => matrix(2) <= break;
when x"083" => matrix(3) <= break;
when x"005" => matrix(4) <= break;
when x"004" => matrix(5) <= break;
when x"003" => matrix(6) <= break;
when x"072" => matrix(7) <= break;
joy2(1) <= break; -- keyrah
-- duplicate scan
-- code for down
-- key and joy2 right?
-- 3, W, A, 4, Z, S, E, left-SHIFT
when x"026" => matrix(8) <= break;
when x"01D" => matrix(9) <= break;
when x"01C" => matrix(10) <= break;
when x"025" => matrix(11) <= break;
when x"01A" => matrix(12) <= break;
when x"01B" => matrix(13) <= break;
when x"024" => matrix(14) <= break;
when x"012" => matrix(15) <= break;
-- 5, R, D, 6, C, F, T, X
when x"02E" => matrix(16) <= break;
when x"02D" => matrix(17) <= break;
when x"023" => matrix(18) <= break;
when x"036" => matrix(19) <= break;
when x"021" => matrix(20) <= break;
when x"02B" => matrix(21) <= break;
when x"02C" => matrix(22) <= break;
when x"022" => matrix(23) <= break;
-- 7, Y, G, 8, B, H, U, V
when x"03D" => matrix(24) <= break;
when x"035" => matrix(25) <= break;
when x"034" => matrix(26) <= break;
when x"03E" => matrix(27) <= break;
when x"032" => matrix(28) <= break;
when x"033" => matrix(29) <= break;
when x"03C" => matrix(30) <= break;
when x"02A" => matrix(31) <= break;
-- 9, I, J, 0, M, K, O, N
when x"046" => matrix(32) <= break;
when x"043" => matrix(33) <= break;
when x"03B" => matrix(34) <= break;
when x"045" => matrix(35) <= break;
when x"03A" => matrix(36) <= break;
when x"042" => matrix(37) <= break;
when x"044" => matrix(38) <= break;
when x"031" => matrix(39) <= break;
-- +, P, L, -, ., :, @, COMMA
when x"04E" => matrix(40) <= break;
when x"04D" => matrix(41) <= break;
when x"04B" => matrix(42) <= break;
when x"055" => matrix(43) <= break;
when x"049" => matrix(44) <= break;
when x"04C" => matrix(45) <= break;
when x"054" => matrix(46) <= break;
when x"041" => matrix(47) <= break;
-- POUND, *, ;, HOME, right SHIFT, =, UP-ARROW, /
when x"170" => matrix(48) <= break;
when x"05B" => matrix(49) <= break;
when x"052" => matrix(50) <= break;
when x"16C" => matrix(51) <= break;
when x"059" => matrix(52) <= break;
when x"05D" => matrix(53) <= break;
when x"171" => matrix(54) <= break;
when x"04A" => matrix(55) <= break;
-- 1, LEFT-ARROW, CTRL, 2, SPACE, C=, Q, RUN/STOP
when x"016" => matrix(56) <= break;
when x"00E" => matrix(57) <= break;
when x"00D" => matrix(58) <= break;
when x"01E" => matrix(59) <= break;
when x"029" => matrix(60) <= break;
when x"014" => matrix(61) <= break;
when x"015" => matrix(62) <= break;
when x"076" => matrix(63) <= break;
when others => null;
end case;
end if;
when ParityBit => ps2state <= Idle; -- was StopBit. See if
-- changing this fixed munching
-- of first bit of back-to-back bytes.
when StopBit => ps2state <= Idle;
when others => ps2state <= Idle;
end case;
end if;
-------------------------------------------------------------------------
-- Update C64 CIA ports
-------------------------------------------------------------------------
-- Whenever a PS2 key goes down, clear the appropriate bit(s) in the
-- matrix. Whenever the corresponding key goes up, set the appropriate
-- bit(s) again. This matrix can then be used to emulate the matrix for
-- interfacing with the CIAs.
-- We will use the VICE keyboard mapping so that we are default with the
-- keyrah2 C64 keyboard to USB adapter.
-- C64 keyboard matrix can be found at: http://sta.c64.org/cbm64kbdlay.html
-- $DC01 bits
-- 0 1 2 3 4 5 6 7
-- $DC00 values
-- Bit#0 $FE Delete Return right F7 F1 F3 F5 down
-- Bit#1 $FD 3 W A 4 Z S E left Shift
-- Bit#2 $FB 5 R D 6 C F T X
-- Bit#3 $F7 7 Y G 8 B H U V
-- Bit#4 $EF 9 I J 0 M K O N
-- Bit#5 $DF + P L minus . : @ ,
-- Bit#6 $BF pound * ; Home rshift = ^ slash
-- Bit#7 $7F 1 _ CTRL 2 Space C= Q Run/Stop
-- RESTORE - Hardwire to NMI
-- Keyrah v2 claims to use default VICE matrix. Yet to find that clearly
-- summarised. Will probably just exhaustively explore it with my keyrah
-- when it arrives.
-- keyboard scancodes for the more normal keys from a keyboard I have here
-- (will replace these with the keyrah obtained ones)
-- $DC01 bits
-- 0 1 2 3 4 5 6 7
-- $DC00 values
-- Bit#0 $FE E0 71 5A E0 74 83 05 04 03 72
-- Bit#1 $FD 26 1D 1C 25 1A 1B 24 12
-- Bit#2 $FB 2E 2D 23 36 21 2B 2C 22
-- Bit#3 $F7 3D 35 34 3E 32 33 3C 2A
-- Bit#4 $EF 46 43 3B 45 3A 42 44 31
-- Bit#5 $DF 55 4D 4B 4E 49 54 5B 41
-- Bit#6 $BF 52 5D 4C E0 6C 59 E0 69 75 4A
-- Bit#7 $7F 16 6B 14 1E 29 11 15 76
-- RESTORE - 0E (`/~ key)
-- C64 drives lines low on $DC00, and then reads $DC01
-- This means that we read from porta_in, to compute values for portb_out
portb_value := x"FF";
for i in 0 to 7 loop
if porta_in(i)='0' then
for j in 0 to 7 loop
portb_value(j) := portb_value(j) and matrix((i*8)+j);
end loop; -- j
end if;
end loop;
if keyboard_column8_select_in='0' then
for j in 0 to 7 loop
portb_value(j) := portb_value(j) and matrix(64+j);
end loop; -- j
end if;
-- We should also do it the otherway around as well
porta_value := x"FF";
for i in 0 to 7 loop
if portb_in(i)='0' then
for j in 0 to 7 loop
porta_value(j) := porta_value(j) and matrix((j*8)+i);
end loop; -- j
end if;
end loop;
-- Keyboard rows and joystick 1
portb_out(7 downto 5) <= portb_value(7 downto 5);
portb_out(4) <= portb_value(4) and joy1(4);
portb_out(3) <= portb_value(3) and joy1(3);
portb_out(2) <= portb_value(2) and joy1(2);
portb_out(1) <= portb_value(1) and joy1(1);
portb_out(0) <= portb_value(0) and joy1(0);
-- Keyboard columns and joystick 2
porta_out(7 downto 5) <= porta_value(7 downto 5);
porta_out(4) <= porta_value(4) and joy2(4);
porta_out(3) <= porta_value(3) and joy2(3);
porta_out(2) <= porta_value(2) and joy2(2);
porta_out(1) <= porta_value(1) and joy2(1);
porta_out(0) <= porta_value(0) and joy2(0);
end if;
end process keyread;
end behavioural;