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INCLUDE "constants.asm"
SECTION "Serial handler", ROM0[$602]
Serial::
push af
push bc
push de
push hl
ldh a, [hLinkPlayerNumber]
inc a
jr z, .init_player_number
ld a, [rSB]
ldh [hSerialReceive], a
ldh a, [hSerialSend]
ld [rSB], a
ldh a, [hLinkPlayerNumber]
cp 2
jr z, .done
ld a, 1 << rSC_ON
ld [rSC], a
jr .done
.init_player_number
ld a, [rSB]
ldh [hSerialReceive], a
ldh [hLinkPlayerNumber], a
cp 2
jr z, .master
xor a
ld [rSB], a
ld a, 3
ld [rDIV], a
.wait
ld a, [rDIV]
bit 7, a
jr nz, .wait
ld a, 1 << rSC_ON
ld [rSC], a
jr .done
.master
xor a
ld [rSB], a
.done
ld a, 1
ldh [hSerialReceived], a
ld a, SERIAL_NO_DATA_BYTE
ldh [hSerialSend], a
pop hl
pop de
pop bc
pop af
reti
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