Patent ID: 7451266
Filing Date: 2008-11-11
Classification: G06F,G11C

Abstract:
1. A nonvolatile memory device comprising: an erasable and writable nonvolatile memory; and a control circuit, wherein said control circuit performs replacement processing of memory areas according to a prescribed timing, wherein said replacement processing is accomplished by writing data stored 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, wherein each said memory area holds rewrite frequency data, wherein said control circuit references the rewrite frequency data to search for an alternative memory area having a rewrite frequency higher than a rewrite frequency of said first memory area and being closest to an average rewrite frequency based on rewrite frequencies of a plurality of memory areas, and to use the alternative memory area as said second memory area.