.include "tn2313def.inc"

.def	Null			=r2	;Register mit Wert $00

.def	tmp			=r9	;Interrupt-Temp Register
.def	Vorteiler1		=r10
.def	Vorteiler2		=r11


.def	Temp 			=r16  	;Temp Register
.def	TempH			=r17	;TempHigh Register
.def	Temp3			=r18	;Temp3 Register
.def	Sekunde			=r20

.def	ButtonCT		=r23	;UpCounter for hold down button

.equ	Status			=GPIOR0	;Statusregister 

.equ	RotaryFlag		=1	;used Flags
.equ	DirectionFlag		=2
.equ	NewRotFlag		=3
.equ	ButtonFlag		=4
.equ	NewButtonFlag		=5
	

**************TIMER INIT**************************

;8 Bit Timer0 (SystemTime)
 ldi	Temp, 0b00000010
 out	TCCR0A, Temp			;CTC-Mode
 ldi	Temp, 0b00000011		;Prescaler 64
 out	TCCR0B, Temp
 ldi	Temp, 125				
 out	OCR0A, Temp


***************INTERRUPT SERVICE********************

;System main timer
SysTime:
 in	tmp, SREG
 push	tmp
 push	Temp

 sbi	Status, DispFlag		;enable Put_Display sub
 
 in	Temp, PinA			;read RotaryEncoder
 andi	Temp, 0b00000011
 cpi	Temp, 0b00000011 		;only if both lines are High, enable direction check
 brne	_ST0
 cbi	Status, RotaryFlag

_ST0:
 sbic	Status, RotaryFlag		;run only, if direction check is enabled
 rjmp	_ST1

 sbrc	Temp, 0				;run only, if line 0 is Low
 rjmp	_ST1

 cbi	Status, DirectionFlag		;if right turn, clear DirectionFlag
 sbrc	Temp, 1
 sbi	Status, DirectionFlag		;if left turn, set DirectionFlag
 sbi	Status, NewRotFlag
 sbi	Status, RotaryFlag		;disable direction check

_ST1:
 dec	Vorteiler1			;TimePrescaler1
 brne	_ST3
 ldi	Temp, 8
 mov	Vorteiler1, Temp
 
 sbic	PinB, 1				;read Button
 rjmp	_ST1A
 
 sbic	Status, ButtonFlag		;run only, if High -> Low transition
 rjmp	_ST1B

 sbi	Status, ButtonFlag		;disable new button pulse detection
 sbi	Status, NewButtonFlag		;set NewButtonFlag
 rjmp	_ST2
 
_ST1A:
 cbi	Status, ButtonFlag		;if button is released, enable new pulse detection
 clr	ButtonCT			;clear button counter
 rjmp	_ST2

_ST1B:
 cpi	ButtonCT, 255			;if button is hold down, increment button counter up to 255
 breq	_ST2
 inc	ButtonCT

_ST2: 
 dec	Vorteiler2			;TimePrescaler2
 brne	_ST3
 ldi	Temp, 125
 mov	Vorteiler2, Temp
 inc	Sekunde

_ST3:
 pop	Temp
 pop	tmp
 out	SREG, tmp

 reti