| 摘要 |
PROBLEM TO BE SOLVED: To improve the reliability of a memory in which data cannot be overwritten nor erased by byte units. SOLUTION: When writing data are transmitted from a main boy processor 2 to a storage device 1, a control means 1b decodes an address by referring to a decoder, and writes data in the new sector or block of a storage area 1a. The decoder is constituted of two stags, and when part of the storage area 1a of the storage device 1 is destroyed, or when part of decoders 1d or 1e is destroyed, one or both of the decoders 1d and 1e in two stages is rewritten. Thus, decoding to the destroyed part is not performed, and even when a storage medium having possibility that part of it is destroyed, such as an EEPROM, a flash memory or the like, is used as the decoder, any probability that the address is turned into an error can be sharply reduced. |
