Nonvolatile memory wear leveling by data replacement processing

A nonvolatile memory device comprising:

• an erasable and writable nonvolatile memory;
• and
• a control circuit,
• wherein said control circuit is enabled to perform replacement processing of memory areas at a prescribed timing, and
• wherein said replacement processing is accomplished by replacing with a prescribed unused memory area a prescribed used memory area in which rewriting is less frequent than in the prescribed unused memory area.

A nonvolatile memory device comprising:

• an erasable and writable nonvolatile memory;
• and
• a control circuit,
• wherein said control circuit is enabled to perform replacement processing of memory areas at a prescribed timing, and
• wherein said replacement processing is accomplished by replacing a prescribed memory area with another in which rewriting is less frequent than that prescribed memory area and placing said other memory area in an unused state while said prescribed memory area after the replacement is being used.

A nonvolatile memory device comprising:

• an erasable and writable nonvolatile memory;
• and
• a control circuit,
• wherein said nonvolatile memory has an unused area distinguishing table for storing a distinguishing flag which indicates whether or not any memory area is an unused area,
• wherein said control circuit, in write processing, makes one of the unused memory areas indicated by said distinguishing flag the destination for data writing and is enabled to perform replacement processing at a prescribed timing on the used memory area indicated by said distinguishing flag, and
• wherein said replacement processing is accomplished by writing stored data in a first memory area in which rewriting is relatively infrequent into an unused second memory area, and making the second memory area into which the writing has been done a used area in place of said first memory area.