m820241212LEDBLINK.asm

;; (C) David Vajda
;; 2024-12-12
;; PORT B, LED Blink/Count

.include "m8def.inc"

ldi r16, HIGH (RAMEND)
out SPH, r16
ldi r16, LOW (RAMEND)
out SPL, r16

ldi r16, 0xff
out DDRB, r16

ldi r16, 0xff
loop1:
out PORTB, r16
rcall sleep
dec r16
rjmp loop1

sleep:
push r16
push r17
ldi r16, 0xff
sleep_loop1:
ldi r17, 0xff
sleep_loop2:
dec r17
brne sleep_loop2
dec r16
brne sleep_loop1
pop r17
pop r16
ret