Patent ID: 8001315

Claim:
A control method of a memory device including a storage area formed of a nonvolatile semiconductor memory, the method comprising: updating a file stored in the storage area by using a file system which supports an incremental write method; recording, in the storage area, an allocation table representing a correlation between a logical address indicating a recording position of the file and a virtual address representing a virtual recording position of the file and management information of the allocation table; recording position information representing a recording position of the management information in a position information area of the storage area; reading the position information, based on format information of the storage area; accessing a file stored in the storage area, based on the management information acquired by the position information; logically formatting the storage area on the basis of the file system; recording the format information in the storage area; reading the format information from the storage area; reading the position information from the position information area by using the logical address of the position information included in the format information; and reading the management information by using the position information, wherein the format information includes a size and a logical address of the position information.