pokecrystal/engine/time.asm

; Functions relating to the timer interrupt and the real-time-clock.


AskTimer: ; 591
	push af
	ld a, [$ffe9]
	and a
	jr z, .asm_59a
	call Timer

.asm_59a
	pop af
	reti
; 59c


LatchClock: ; 59c
; latch clock counter data
	ld a, 0
	ld [MBC3LatchClock], a
	ld a, 1
	ld [MBC3LatchClock], a
	ret
; 5a7


UpdateTime: ; 5a7
	call GetClock
	call FixDays
	call FixTime
	callba GetTimeOfDay
	ret
; 5b7


GetClock: ; 5b7
; store clock data in hRTCDayHi-hRTCSeconds

; enable clock r/w
	ld a, SRAM_ENABLE
	ld [MBC3SRamEnable], a

; clock data is 'backwards' in hram

	call LatchClock
	ld hl, MBC3SRamBank
	ld de, MBC3RTC

	ld [hl], RTC_S
	ld a, [de]
	and $3f
	ld [hRTCSeconds], a

	ld [hl], RTC_M
	ld a, [de]
	and $3f
	ld [hRTCMinutes], a

	ld [hl], RTC_H
	ld a, [de]
	and $1f
	ld [hRTCHours], a

	ld [hl], RTC_DL
	ld a, [de]
	ld [hRTCDayLo], a

	ld [hl], RTC_DH
	ld a, [de]
	ld [hRTCDayHi], a

; unlatch clock / disable clock r/w
	call CloseSRAM
	ret
; 5e8


FixDays: ; 5e8
; fix day count
; mod by 140

; check if day count > 255 (bit 8 set)
	ld a, [hRTCDayHi] ; DH
	bit 0, a
	jr z, .daylo
; reset dh (bit 8)
	res 0, a
	ld [hRTCDayHi], a ; DH
	
; mod 140
; mod twice since bit 8 (DH) was set
	ld a, [hRTCDayLo] ; DL
.modh
	sub 140
	jr nc, .modh
.modl
	sub 140
	jr nc, .modl
	add 140
	
; update dl
	ld [hRTCDayLo], a ; DL

; unknown output
	ld a, $40 ; %1000000
	jr .set

.daylo
; quit if fewer than 140 days have passed
	ld a, [hRTCDayLo] ; DL
	cp 140
	jr c, .quit
	
; mod 140
.mod
	sub 140
	jr nc, .mod
	add 140
	
; update dl
	ld [hRTCDayLo], a ; DL
	
; unknown output
	ld a, $20 ; %100000
	
.set
; update clock with modded day value
	push af
	call SetClock
	pop af
	scf
	ret
	
.quit
	xor a
	ret
; 61d


FixTime: ; 61d
; add ingame time (set at newgame) to current time
;				  day     hr    min    sec
; store time in CurDay, hHours, hMinutes, hSeconds

; second
	ld a, [hRTCSeconds] ; S
	ld c, a
	ld a, [StartSecond]
	add c
	sub 60
	jr nc, .updatesec
	add 60
.updatesec
	ld [hSeconds], a
	
; minute
	ccf ; carry is set, so turn it off
	ld a, [hRTCMinutes] ; M
	ld c, a
	ld a, [StartMinute]
	adc c
	sub 60
	jr nc, .updatemin
	add 60
.updatemin
	ld [hMinutes], a
	
; hour
	ccf ; carry is set, so turn it off
	ld a, [hRTCHours] ; H
	ld c, a
	ld a, [StartHour]
	adc c
	sub 24
	jr nc, .updatehr
	add 24
.updatehr
	ld [hHours], a
	
; day
	ccf ; carry is set, so turn it off
	ld a, [hRTCDayLo] ; DL
	ld c, a
	ld a, [StartDay]
	adc c
	ld [CurDay], a
	ret
; 658

Function658: ; 658
	xor a
	ld [StringBuffer2], a
	ld a, $0
	ld [$d089], a
	jr .asm_677

	call UpdateTime
	ld a, [hHours]
	ld [$d087], a
	ld a, [hMinutes]
	ld [$d088], a
	ld a, [hSeconds]
	ld [$d089], a
	jr .asm_677

.asm_677
	ld a, $5
	ld hl, $40ed
	rst FarCall
	ret
; 67e



Function67e: ; 67e
	call Function685
	call SetClock
	ret
; 685

Function685: ; 685
	xor a
	ld [hRTCSeconds], a
	ld [hRTCMinutes], a
	ld [hRTCHours], a
	ld [hRTCDayLo], a
	ld [hRTCDayHi], a
	ret
; 691


SetClock: ; 691
; set clock data from hram

; enable clock r/w
	ld a, SRAM_ENABLE
	ld [MBC3SRamEnable], a
	
; set clock data
; stored 'backwards' in hram

	call LatchClock
	ld hl, MBC3SRamBank
	ld de, MBC3RTC
	
; seems to be a halt check that got partially commented out
; this block is totally pointless
	ld [hl], RTC_DH
	ld a, [de]
	bit 6, a ; halt
	ld [de], a
	
; seconds
	ld [hl], RTC_S
	ld a, [hRTCSeconds]
	ld [de], a
; minutes
	ld [hl], RTC_M
	ld a, [hRTCMinutes]
	ld [de], a
; hours
	ld [hl], RTC_H
	ld a, [hRTCHours]
	ld [de], a
; day lo
	ld [hl], RTC_DL
	ld a, [hRTCDayLo]
	ld [de], a
; day hi
	ld [hl], RTC_DH
	ld a, [hRTCDayHi]
	res 6, a ; make sure timer is active
	ld [de], a
	
; cleanup
	call CloseSRAM ; unlatch clock, disable clock r/w
	ret
; 6c4


Function6c4: ; 6c4
	xor a
	push af
	ld a, $0
	call GetSRAMBank
	pop af
	ld [$ac60], a
	call CloseSRAM
	ret
; 6d3

Function6d3: ; 6d3
	ld hl, $ac60
	push af
	ld a, $0
	call GetSRAMBank
	pop af
	or [hl]
	ld [hl], a
	call CloseSRAM
	ret
; 6e3

Function6e3: ; 6e3
	ld a, $0
	call GetSRAMBank
	ld a, [$ac60]
	call CloseSRAM
	ret
; 6ef