| 摘要 |
<p>PURPOSE:To exchange before the life of a P-ROM ends by disposing a specific area for storing the number of the writings of the data of the P-ROM on the P-ROM. CONSTITUTION:The specific area 7a for recording the number of the writings of the data of its own on the electrically erasable P-ROM 7 is disposed on a specific address on the ROM 7 to increase the number of the writings of the address of the area 7a corresponding to a writing executed address at every writing to the RAM 7. Therefore, the area 7a is monitored, thereby, the number of times of the data writings of the ROM 7 can be recognized. Thereby, since the number of times of the data writings of the ROM 7 can be recognized by monitoring the area 7a, the device can be exchanged before the life of the ROM 7 is completed.</p> |
