;
; ARBK_Praktikum_4_Polling.asm
;

; Definitions
.def temp = r16
.def leds = r17
.def counter0 = r18
.def counter1 = r19
.def counter2 = r20


; Jump Table
.org 0x00			; Reset Handler
	rjmp main

main:
	; DDR setzen
	ldi temp,0xFF
	out DDRB,temp
	ldi temp,0x00
	out DDRD,temp
	ldi temp,0xFF
	out PORTD,temp
	; LEDs ausschalten
	ldi leds,0x00
	out PORTB,leds
	; stackpointer
	ldi temp,HIGH(RAMEND)
	out SPH,temp
	ldi temp,LOW(RAMEND)
	out SPL,temp

;blinken
blink:
	rcall taster
	out PORTB,leds
	rcall wait
	ldi temp,0x00
	out PORTB,temp
	rcall wait
	rjmp blink

; taster auswerten
taster:
	in temp,PIND
	cbr temp,251
	cpi temp,0
	breq ledR
	in temp,PIND
	cbr temp,247
	cpi temp,0
	breq ledY
	ret

ledY:
	cpi leds,0x02
	breq turnoff
	ldi leds,0x02
	ret

ledR:
	cpi leds,0x01
	breq turnoff
	ldi leds,0x01
	ret

turnoff:
	ldi leds,0x00
	ret

; warten
wait:
	inc counter0
	cpi counter0,0xFF
	brlo wait

	inc counter1
	cpi counter1,0xFF
	brlo wait

	inc counter2
	cpi counter2,0x07
	brlo wait

	ldi counter0,0x00
	ldi counter1,0x00
	ldi counter2,0x00

	ret