.def tmp = r16
.def mask = r17

.cseg
    rjmp reset

.org $00C
    rjmp blink

.org $010
    rjmp blink

reset:
    ldi tmp, high(RAMEND)
    out SPH, tmp
    ldi tmp, low(RAMEND)
    out SPL, tmp

    ldi tmp, 0x01
    out PORTA, tmp
    out DDRA,  tmp

    ldi mask, 0x01

    ldi tmp, (1 << WGM11) | (1 << WGM10)
    out TCCR1A, tmp

    ldi tmp, (1 << WGM12) | (1 << WGM13) | (1 << CS11)
    out TCCR1B, tmp

    ldi tmp, high(23039)
    out OCR1AH, tmp
    ldi tmp, low(23039)
    out OCR1AL, tmp

    ldi tmp, high(10000)
    out OCR1BH, tmp
    ldi tmp, low(10000)
    out OCR1BL, tmp

    ldi tmp, (1 << OCIE1A) | (1 << TOIE1)
    out TIMSK, tmp

    sei

main:
rjmp main

blink:
    in tmp, PORTA
    eor tmp, mask
    out PORTA, tmp

reti