<p>The runaway detection device is equipped with a first register (12) having a first field and a second field, a second register (13) that stores the first field data before the stored content of the first register is updated, a comparator (14) that compares the second field data with the stored content of the second register and outputs a match signal if they match, and a timer (11) that counts a certain period of time and that receives the match signal and is reset.</p>
