.cseg
    .org 0x00
    rjmp start
    .org 0x1c rjmp inint
    .org 0x2A
    ;rjmp start
start:
    ;stack init
    ldi r16, high(RAMEND)
    out SPH, r16
    ldi r17, low(RAMEND)
    out SPL, r17
    ;global and application interrupt enable
    ldi r16, 0x00
    out SFIOR, r16
    ldi r16, (1<<ADEN)|(1<<ADPS2)|(1<<ADPS1)|(1<<ADPS0)|(1<<ADIE)|(1<<ADATE)|(1<<ADIF)
    out ADCSRA, r16
    ldi r16, (1<<REFS0)|(0<<REFS1)|(1<<ADLAR)|(0<<MUX4)|(0<<MUX3)|(0<<MUX2)|(0<<MUX1)|(0<<MUX0) ; 0<<MUX0
    out ADMUX, r16
    ;fast mode PMW
    ldi r17, (1<<COM01)|(1<<WGM01)|(1<<WGM00)|(1<<CS00)
    out TCCR0, r17
    clr r16
    out TCNT0, r16
    out OCR0, r16
    out TIMSK, r16
    out TIFR, r16
    out OCR0, r16
    sbi DDRB, 3
    sei
    sbi ADCSRA, ADSC
main:
    rjmp main
inint:
    in r20, ADCH
    out OCR0, r20
    reti