pokecrystal-board/engine/rtc/rtc.asm

StopRTC: ; unreferenced
	ld a, SRAM_ENABLE
	ld [MBC3SRamEnable], a
	call LatchClock
	ld a, RTC_DH
	ld [MBC3SRamBank], a
	ld a, [MBC3RTC]
	set 6, a ; halt
	ld [MBC3RTC], a
	call CloseSRAM
	ret

StartRTC:
	ld a, SRAM_ENABLE
	ld [MBC3SRamEnable], a
	call LatchClock
	ld a, RTC_DH
	ld [MBC3SRamBank], a
	ld a, [MBC3RTC]
	res 6, a ; halt
	ld [MBC3RTC], a
	call CloseSRAM
	ret

GetTimeOfDay::
; get time of day based on the current hour
	ldh a, [hHours] ; hour
	ld hl, TimesOfDay

.check
; if we're within the given time period,
; get the corresponding time of day
	cp [hl]
	jr c, .match
; else, get the next entry
	inc hl
	inc hl
; try again
	jr .check

.match
; get time of day
	inc hl
	ld a, [hl]
	ld [wTimeOfDay], a
	ret

TimesOfDay:
; hours for the time of day
; 0400-0959 morn | 1000-1759 day | 1800-0359 nite
	db MORN_HOUR, NITE_F
	db DAY_HOUR,  MORN_F
	db NITE_HOUR, DAY_F
	db MAX_HOUR,  NITE_F
	db -1, MORN_F

BetaTimesOfDay: ; unreferenced
	db 20, NITE_F
	db 40, MORN_F
	db 60, DAY_F
	db -1, MORN_F

StageRTCTimeForSave:
	call UpdateTime
	ld hl, wRTC
	ld a, [wCurDay]
	ld [hli], a
	ldh a, [hHours]
	ld [hli], a
	ldh a, [hMinutes]
	ld [hli], a
	ldh a, [hSeconds]
	ld [hli], a
	ret

SaveRTC:
	ld a, SRAM_ENABLE
	ld [MBC3SRamEnable], a
	call LatchClock
	ld hl, MBC3RTC
	ld a, RTC_DH
	ld [MBC3SRamBank], a
	res 7, [hl]
	ld a, BANK(sRTCStatusFlags)
	ld [MBC3SRamBank], a
	xor a
	ld [sRTCStatusFlags], a
	call CloseSRAM
	ret

StartClock::
	call GetClock
	call _FixDays
	call FixDays
	jr nc, .skip_set
	; bit 5: Day count exceeds 139
	; bit 6: Day count exceeds 255
	call RecordRTCStatus ; set flag on sRTCStatusFlags

.skip_set
	call StartRTC
	ret

_FixDays:
	ld hl, hRTCDayHi
	bit 7, [hl]
	jr nz, .set_bit_7
	bit 6, [hl]
	jr nz, .set_bit_7
	xor a
	ret

.set_bit_7
	; Day count exceeds 16383
	ld a, %10000000
	call RecordRTCStatus ; set bit 7 on sRTCStatusFlags
	ret

ClockContinue:
	call CheckRTCStatus
	ld c, a
	and %11000000 ; Day count exceeded 255 or 16383
	jr nz, .time_overflow

	ld a, c
	and %00100000 ; Day count exceeded 139
	jr z, .dont_update

	call UpdateTime
	ld a, [wRTC + 0]
	ld b, a
	ld a, [wCurDay]
	cp b
	jr c, .dont_update

.time_overflow
	farcall ClearDailyTimers
	farcall Function170923
	ld a, BANK(s5_aa8c) ; aka BANK(s5_b2fa)
	call OpenSRAM
	ld a, [s5_aa8c]
	inc a
	ld [s5_aa8c], a
	ld a, [s5_b2fa]
	inc a
	ld [s5_b2fa], a
	call CloseSRAM
	ret

.dont_update
	xor a
	ret

_InitTime::
	call GetClock
	call FixDays
	ld hl, hRTCSeconds
	ld de, wStartSecond

	ld a, [wStringBuffer2 + 3]
	sub [hl]
	dec hl
	jr nc, .okay_secs
	add 60
.okay_secs
	ld [de], a
	dec de

	ld a, [wStringBuffer2 + 2]
	sbc [hl]
	dec hl
	jr nc, .okay_mins
	add 60
.okay_mins
	ld [de], a
	dec de

	ld a, [wStringBuffer2 + 1]
	sbc [hl]
	dec hl
	jr nc, .okay_hrs
	add 24
.okay_hrs
	ld [de], a
	dec de

	ld a, [wStringBuffer2]
	sbc [hl]
	dec hl
	jr nc, .okay_days
	add 140
	ld c, 7
	call SimpleDivide

.okay_days
	ld [de], a
	ret