m820250830PORTBBCD27SEG.asm

;; (C) David Vajda
;; 2025-08-30
;; AVR/ATMega8 LED out PORT B, vereinfachte Aufgabe BCD27Seg mit 74xxx TTL Baustein

.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:
com r16
out PORTB, r16
com r16
rcall delay
dec r16
rjmp loop1

delay:
push r16
push r17
ldi r16, 0xff
loop2:
ldi r17, 0xff
loop3:
dec r17
brne loop3
dec r16
brne loop2
pop r17
pop r16
ret