.def tmp = r16
.def mask = r20
.def step = r21
.def mtp = r22

.equ delayCnt = 2

.cseg

rjmp reset

.org 0x00C
    rjmp blink

.org 0x010
    rjmp blink

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

    ldi tmp, 0xff
    out DDRA, tmp
    out PORTA, tmp
    out PORTB, tmp

    ldi tmp, 0x00
    out DDRB, tmp

    ldi mtp, 0x00

    ldi mask, 0x01
    ldi step, 0x0a

    ldi tmp, (1 << PD5)
    out DDRD, tmp

    ldi tmp, (1 << COM1A0) | (1 << WGM10)
    out TCCR1A, tmp

    ldi tmp, (1 << WGM12) | (1 << CS12)
    out TCCR1B, tmp

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

    ldi tmp, high(125)
    out OCR1AH, tmp
    ldi tmp, low(125)
    out OCR1AL, tmp

    sei

main:
    sbis PINB, 0
        rcall smanji
    sbis PINB, 1
        rcall povecaj
    rcall delay
rjmp main

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

smanji:
    out DDRD, mtp
    in tmp, OCR1AL

    cpi tmp, 0x02
    brlo end
    sub tmp, step
    end:
        out OCR1AL, tmp
ret

povecaj:
    out DDRD, mtp
    in tmp, OCR1AL

    cpi tmp, 0xfd
    brsh kraj
    add tmp, step
    kraj:
        out OCR1AL, tmp
ret

delay:
    clr r17
    clr r18
    ldi r19, delayCnt
    delay_loop:
        dec r17
        brne delay_loop
            dec r18
            brne delay_loop
                dec r19
                brne delay_loop
ret