Blikač LED

;pokus

.include    "tn13def.inc"

.def    POM=r16

.org    0x0000              ;zacatek kodu
    RJMP    RESET           ;skok na start po resetu


.org    0x0010              ;zacatek vlastniho programu

RESET:
    LDI POM,low(RAMEND)     ;nastavi stack pointer
    OUT  SPL,POM

    LDI  POM,0B00000011     ;nastavi vystupni piny
    OUT  DDRB,POM

LOOP:
    SBI PORTB,0         ;PB0=0, PB1=1
    CBI PORTB,1
    RCALL CEKANI            ;CEKACI SUB
    CBI PORTB,0         ;PB0=1, PB1=0
    SBI PORTB,1
    RCALL CEKANI            ;CEKACI SUB
    RJMP    LOOP                ;znovu na navesti LOOP

CEKANI:
    PUSH    r18             ;ulozit pouzivane registry do STACKU
    PUSH    r17
    PUSH    r16

    LDI r16, 100
L1: DEC r16
    LDI r17, 100
L2: DEC r17
    LDI r18, 125
L3: DEC r18
    CPI r18, 0
    BRNE    L3
    CPI r17, 0
    BRNE    L2
    CPI r16, 0
    BRNE    L1

    POP r16             ;nacist puvodni obsah registru ze STACKU
    POP r17
    POP r18

    RET                 ;navrat do hlavniho programu