| 摘要 |
<p>PURPOSE:To extend the life of an EEPROM corresponding to the size of a reverse area and to improve its reliability by providing in a data write area a reserve area and a designation area to designate a data write able area and writing data in the reserve area in accordance with a designation from the designation area. CONSTITUTION:In the EEPROM 1, the data write area 11, the reserve area 12 having plural areas 1-4, and the designation area 13 are disposed. When data is written in the area 11, zero is written in the area 13, whether data is correctly written in or not is checked every time said writing is executed, and in case a writing comes unable, +1 is written in the area 13. Thereafter, the value is added by +1 when writing is unable, and thus a write block is udpated. Upon writing data, a CPU 3 refers to the designation area 13 to always enable a write of data, and to extend the life of the EEPROM 1.</p> |
