.include "m8515def.inc"
.def temp=r16
.def var=r17

.org $00
rjmp INIT
.org $07
rjmp TIMER_OV0_HANDLER


DELAY:
ldi r18, 1
ldi r19, 0xFF
ldi r20, 0xFF
CONT:
dec r20
brne CONT
dec r19
brne CONT
dec r18
brne CONT
ret

INIT:
ldi temp, high(RAMEND)
out SPH, temp
ldi temp, low(RAMEND)
out SPL, temp
; Setting PORTA, PORTB
ldi temp, 0b11111111
out DDRA, temp
ldi temp, 0b11111111
out DDRB, temp
; Setting Timer Interrupt
;ldi temp, 0b00000101
; 1 << (CS02) = 0b00000001 << 2 = 00000100
; 1 << (CS00) = 0b00000001 << 0 = 00000001
ldi temp, (1 << CS02) | (1 << CS00)
out TCCR0, temp
ldi temp, (1 << TOV0)
out TIFR, temp
ldi temp, (1 << TOIE0)
out TIMSK, temp
sei

ldi var, 0x00

loop:
ldi temp, 0b10101010
out PORTA, temp
rcall DELAY
ldi temp, 0b01010101
out PORTA, temp
rcall DELAY
rjmp loop


TIMER_OV0_HANDLER:
ldi temp, 0b11111111
eor var, temp
out PORTB, var
reti