ATmega16: TC0 kerdes

[Daniel VASARHELYI]

Hali. Uj vagyok ATmega-ban, es lenne egy kerdesem.
1MHz-en jaratom belso RC oszcillatorral, a timer0 prescalerje 1024 es a
TCCR0 tulcsordulasakor meghivodik az OVF0 interrupt.

1 MHz/1024/256/2 = 1.9 hz. Megis inkabb 1Hz-nek tunik ez az ertek. Alant
mellekelem a sample programot, valaki megmondana, hogy min csusztam el?

asd

.include "m16def.inc"
.equ ProgStart =0x02a
.def blink_counter =r17
.def IRQ_SREG =r01
.def temp =r20
.def temp2 =r21

.org 0
rjmp RESET

.include "it-table.inc"
.org ProgStart

nullint:
        reti

RESET:
        ldi temp, low(RAMEND)
        out SPL, temp
        ldi temp, high(RAMEND)
        out SPH, temp
        ldi temp, 0b11111111 ; PORTB is output and switch it on
        out DDRA, temp
        out PORTA, temp
        ldi temp, (1<<TOIE0) ; TC0 Overflow Interrupt Enable
        out TIMSK, temp  ; TC Interrupt Mask Register
        ldi temp, 0b101 ; prescaler 1024
        out TCCR0, temp  ; TC Control Register
        sei
forever:
        nop
        nop
        nop
        rjmp forever

OVF0_start:
        in IRQ_SREG, SREG
        inc blink_counter
        out PORTA, blink_counter
        out SREG, IRQ_SREG
        reti




-- 
Daniel VASARHELYI