20. Swap clasic (cu 3 scaune) (ASM)

volatile byte a=1;
volatile byte b=2;
void setup()
{
  Serial.begin(9600);
  asm(
    "mov r26, %0 \n"
    "mov %0, %1  \n"
    "mov %1, r26 \n"
    :"+r" (a), "+r" (b)::"r26"
  );
  Serial.print("a = "); Serial.println (a);
  Serial.print("b = "); Serial.println (b);
}

void loop(){}