Toggle leds with interrupts ATMEGA32A

I have a school task but even the teacher don't know how to do it... We have to create a program that let the leds blink with a frequency of 1Hz. The chip we use is a ATmega32A at 3,6864 MHz. The program must contain interrupts so the main program can go to sleep.

now my question i have found SEI and the RETI functions but do i understand it correctly that i have to write 2 assembly programs?

1 with the main loop to control the leds.

1 that generates the 2Hz interrupt to toggle the leds?

tnx in advance

Solution

i have got the code working the following code is for a ATmega32A with a clock of 3686400Hz crystal

.org 0x000
    rjmp    reset
.org 0x00E
    rjmp    tc0_ocm_isr

.equ    dirleds     =DDRB
.equ    leds        =PORTB
.equ    allout      =0b1111_1111
.equ    allin       =0b0000_0000

.def    temp = r16
.def    allon = r17
.def    ledtemp = r18
.def    bitlow = r20
.def    bithigh= r21

    ldi     ledtemp,0x00
    ldi     allon,0xff
reset:


    ldi     bithigh, 0x07       
    ldi     bitlow, 0x07
    out     OCR1AH,bithigh
    out     OCR1AL,bitlow

    ldi     temp,0b00010000
    out     TIMSK,temp

    ldi     temp,0x0d
    out     TCCR1B,temp

    sei



loop:   
    rjmp    loop


tc0_ocm_isr:    
    eor     ledtemp,allon
    out     DDRB,ledtemp
    reti