.include "m8def.inc"

.equ TAKT = 16000000

.def dsec = r17

.org	0x0000
	rjmp init

.org OC1Aaddr
	rjmp timer1_compare

init:
	;init Stack
	ldi r16,low(RAMEND)
	out SPL,r16
	ldi r16,high(RAMEND)
	out SPH,r16
	
	;init Port
	ldi r16,0xFF
	out DDRB,r16

	;init Timer1
	ldi r16,low(20000-1)			// OCR1A Wert
	out OCR1AL,r16
	ldi r16,high(20000-1)
	out OCR1AH,r16
	ldi r16,(1 << WGM12) | (1 << CS11) 	// CTC mit 1/8 TAKT
	out TCCR1B,r16
	ldi r16,(1 << OCIE1A)			// Overflow Interrupt aktivieren
	out TIMSK,r16

	ldi dsec,0
	ldi r16,0

	sei

loop:
	rjmp loop

timer1_compare:
	inc dsec
	cpi dsec,100
	brne end_isr

an:
	in r16,PINB
	andi r16,1
	brne aus
	sbi PORTB,0
	clr dsec
	reti

aus:
	cbi PORTB,0
	clr dsec

end_isr:
	reti