m8countled06272026extint.asm

;; david vajda
;; 06/27/2026
;; m8 count led by ext int

.include "m8def.inc"

.org 0x000
rjmp RESET
.org INT0addr
rjmp INT0hndlr
.org INT1addr
rjmp INT1hndlr

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

ldi r16, 0xff
out DDRB, r16
ldi r16, 0xff

ldi r16, (1 << CS00) | (1 << CS01)
out MCUCR, r16
ldi r16, (1 << INT0) | (1 << INT1)
out GICR, r16

sei
main001: rjmp main001

INT0hndlr:
dec r16
out PORTB, r16
reti

INT1hndlr:
inc r16
out PORTB, r16
reti