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|
Serial::
; The serial interrupt.
push af
push bc
push de
push hl
ldh a, [hMobileReceive]
and a
jr nz, .mobile
ld a, [wPrinterConnectionOpen]
bit 0, a
jr nz, .printer
ldh a, [hSerialConnectionStatus]
inc a ; is it equal to CONNECTION_NOT_ESTABLISHED?
jr z, .establish_connection
ldh a, [rSB]
ldh [hSerialReceive], a
ldh a, [hSerialSend]
ldh [rSB], a
ldh a, [hSerialConnectionStatus]
cp USING_INTERNAL_CLOCK
jr z, .player2
ld a, (0 << rSC_ON) | (0 << rSC_CLOCK)
ldh [rSC], a
ld a, (1 << rSC_ON) | (0 << rSC_CLOCK)
ldh [rSC], a
jr .player2
.mobile
call MobileReceive
jr .end
.printer
call PrinterReceive
jr .end
.establish_connection
ldh a, [rSB]
cp USING_EXTERNAL_CLOCK
jr z, .player1
cp USING_INTERNAL_CLOCK
jr nz, .player2
.player1
ldh [hSerialReceive], a
ldh [hSerialConnectionStatus], a
cp USING_INTERNAL_CLOCK
jr z, ._player2
xor a
ldh [rSB], a
ld a, 3
ldh [rDIV], a
.wait_bit_7
ldh a, [rDIV]
bit 7, a
jr nz, .wait_bit_7
ld a, (0 << rSC_ON) | (0 << rSC_CLOCK)
ldh [rSC], a
ld a, (1 << rSC_ON) | (0 << rSC_CLOCK)
ldh [rSC], a
jr .player2
._player2
xor a
ldh [rSB], a
.player2
ld a, TRUE
ldh [hSerialReceivedNewData], a
ld a, SERIAL_NO_DATA_BYTE
ldh [hSerialSend], a
.end
pop hl
pop de
pop bc
pop af
reti
Serial_ExchangeBytes::
ld a, $1
ldh [hSerialIgnoringInitialData], a
.loop
ld a, [hl]
ldh [hSerialSend], a
call Serial_ExchangeByte
push bc
ld b, a
inc hl
ld a, $30
.wait
dec a
jr nz, .wait
ldh a, [hSerialIgnoringInitialData]
and a
ld a, b
pop bc
jr z, .load
dec hl
cp SERIAL_PREAMBLE_BYTE
jr nz, .loop
xor a
ldh [hSerialIgnoringInitialData], a
jr .loop
.load
ld [de], a
inc de
dec bc
ld a, b
or c
jr nz, .loop
ret
Serial_ExchangeByte::
.loop
xor a
ldh [hSerialReceivedNewData], a
ldh a, [hSerialConnectionStatus]
cp USING_INTERNAL_CLOCK
jr nz, .not_player_2
ld a, (0 << rSC_ON) | (1 << rSC_CLOCK)
ldh [rSC], a
ld a, (1 << rSC_ON) | (1 << rSC_CLOCK)
ldh [rSC], a
.not_player_2
.loop2
ldh a, [hSerialReceivedNewData]
and a
jr nz, .reset_ffca
ldh a, [hSerialConnectionStatus]
cp USING_EXTERNAL_CLOCK
jr nz, .not_player_1_or_wLinkTimeoutFrames_zero
call CheckwLinkTimeoutFramesNonzero
jr z, .not_player_1_or_wLinkTimeoutFrames_zero
call .delay_15_cycles
push hl
ld hl, wLinkTimeoutFrames + 1
inc [hl]
jr nz, .no_rollover_up
dec hl
inc [hl]
.no_rollover_up
pop hl
call CheckwLinkTimeoutFramesNonzero
jr nz, .loop2
jp SerialDisconnected
.not_player_1_or_wLinkTimeoutFrames_zero
ldh a, [rIE]
and (1 << SERIAL) | (1 << TIMER) | (1 << LCD_STAT) | (1 << VBLANK)
cp 1 << SERIAL
jr nz, .loop2
ld a, [wcf5d]
dec a
ld [wcf5d], a
jr nz, .loop2
ld a, [wcf5d + 1]
dec a
ld [wcf5d + 1], a
jr nz, .loop2
ldh a, [hSerialConnectionStatus]
cp USING_EXTERNAL_CLOCK
jr z, .reset_ffca
ld a, 255
.delay_255_cycles
dec a
jr nz, .delay_255_cycles
.reset_ffca
xor a
ldh [hSerialReceivedNewData], a
ldh a, [rIE]
and (1 << SERIAL) | (1 << TIMER) | (1 << LCD_STAT) | (1 << VBLANK)
sub 1 << SERIAL
jr nz, .rIE_not_equal_8
; LOW($5000)
ld [wcf5d], a
ld a, HIGH($5000)
ld [wcf5d + 1], a
.rIE_not_equal_8
ldh a, [hSerialReceive]
cp SERIAL_NO_DATA_BYTE
ret nz
call CheckwLinkTimeoutFramesNonzero
jr z, .linkTimeoutFrames_zero
push hl
ld hl, wLinkTimeoutFrames + 1
ld a, [hl]
dec a
ld [hld], a
inc a
jr nz, .no_rollover
dec [hl]
.no_rollover
pop hl
call CheckwLinkTimeoutFramesNonzero
jr z, SerialDisconnected
.linkTimeoutFrames_zero
ldh a, [rIE]
and (1 << SERIAL) | (1 << TIMER) | (1 << LCD_STAT) | (1 << VBLANK)
cp 1 << SERIAL
ld a, SERIAL_NO_DATA_BYTE
ret z
ld a, [hl]
ldh [hSerialSend], a
call DelayFrame
jp .loop
.delay_15_cycles
ld a, 15
.delay_cycles
dec a
jr nz, .delay_cycles
ret
CheckwLinkTimeoutFramesNonzero::
push hl
ld hl, wLinkTimeoutFrames
ld a, [hli]
or [hl]
pop hl
ret
SerialDisconnected::
dec a ; a is always 0 when this is called
ld [wLinkTimeoutFrames], a
ld [wLinkTimeoutFrames + 1], a
ret
; This is used to exchange the button press and selected menu item on the link menu.
; The data is sent thrice and read twice to increase reliability.
Serial_ExchangeLinkMenuSelection::
ld hl, wPlayerLinkAction
ld de, wOtherPlayerLinkMode
ld c, 2
ld a, TRUE
ldh [hSerialIgnoringInitialData], a
.asm_847
call DelayFrame
ld a, [hl]
ldh [hSerialSend], a
call Serial_ExchangeByte
ld b, a
inc hl
ldh a, [hSerialIgnoringInitialData]
and a
ld a, FALSE
ldh [hSerialIgnoringInitialData], a
jr nz, .asm_847
ld a, b
ld [de], a
inc de
dec c
jr nz, .asm_847
ret
Serial_PrintWaitingTextAndSyncAndExchangeNybble::
call LoadTilemapToTempTilemap
callfar PlaceWaitingText
call WaitLinkTransfer
jp SafeLoadTempTilemapToTilemap
Serial_SyncAndExchangeNybble::
call LoadTilemapToTempTilemap
callfar PlaceWaitingText
jp WaitLinkTransfer
; One "giant" leap for machinekind
WaitLinkTransfer::
ld a, $ff
ld [wOtherPlayerLinkAction], a
.loop
call LinkTransfer
call DelayFrame
call CheckwLinkTimeoutFramesNonzero
jr z, .check
push hl
ld hl, wLinkTimeoutFrames + 1
dec [hl]
jr nz, .skip
dec hl
dec [hl]
jr nz, .skip
; We might be disconnected
pop hl
xor a
jp SerialDisconnected
.skip
pop hl
.check
ld a, [wOtherPlayerLinkAction]
inc a
jr z, .loop
ld b, 10
.receive
call DelayFrame
call LinkTransfer
dec b
jr nz, .receive
ld b, 10
.acknowledge
call DelayFrame
call LinkDataReceived
dec b
jr nz, .acknowledge
ld a, [wOtherPlayerLinkAction]
ld [wOtherPlayerLinkMode], a
ret
LinkTransfer::
push bc
ld b, SERIAL_TIMECAPSULE
ld a, [wLinkMode]
cp LINK_TIMECAPSULE
jr z, .got_high_nybble
ld b, SERIAL_TIMECAPSULE
jr c, .got_high_nybble
cp LINK_TRADECENTER
ld b, SERIAL_TRADECENTER
jr z, .got_high_nybble
ld b, SERIAL_BATTLE
.got_high_nybble
call .Receive
ld a, [wPlayerLinkAction]
add b
ldh [hSerialSend], a
ldh a, [hSerialConnectionStatus]
cp USING_INTERNAL_CLOCK
jr nz, .player_1
ld a, (0 << rSC_ON) | (1 << rSC_CLOCK)
ldh [rSC], a
ld a, (1 << rSC_ON) | (1 << rSC_CLOCK)
ldh [rSC], a
.player_1
call .Receive
pop bc
ret
.Receive:
ldh a, [hSerialReceive]
ld [wOtherPlayerLinkMode], a
and $f0
cp b
ret nz
xor a
ldh [hSerialReceive], a
ld a, [wOtherPlayerLinkMode]
and $f
ld [wOtherPlayerLinkAction], a
ret
LinkDataReceived::
; Let the other system know that the data has been received.
xor a
ldh [hSerialSend], a
ldh a, [hSerialConnectionStatus]
cp USING_INTERNAL_CLOCK
ret nz
ld a, (0 << rSC_ON) | (1 << rSC_CLOCK)
ldh [rSC], a
ld a, (1 << rSC_ON) | (1 << rSC_CLOCK)
ldh [rSC], a
ret
Function919:: ; unreferenced
ld a, [wLinkMode]
and a
ret nz
ld a, USING_INTERNAL_CLOCK
ldh [rSB], a
xor a
ldh [hSerialReceive], a
ld a, (0 << rSC_ON) | (0 << rSC_CLOCK)
ldh [rSC], a
ld a, (1 << rSC_ON) | (0 << rSC_CLOCK)
ldh [rSC], a
ret
|
