Patent ID: 7475185

Claim:
A nonvolatile memory system which comprises an access device and a nonvolatile memory device and writes file data and file data management information of the file data into the nonvolatile memory device, the nonvolatile memory device including: a nonvolatile main memory containing, a data area which stores the file data and the file data management information, the data area being managed by an allocation unit having continuous clusters as a managing unit of the file data, the allocation unit and the cluster being indicated by a logical address, and being managed by a physical block indicated by a physical address, the allocation unit being equal to or larger than the physical block and the physical block being equal to or larger than the cluster, and a management information area which stores information of the file data and the file data management information; and a memory controller containing an address managing portion which decides physical addresses of the data area in the main memory for storing the file data and the file data management information based on logical addresses of the file data and the file data management information given from the access device, and a main memory access portion which writes the file data and the file data management information into different allocation units of the data area in the main memory according to the physical addresses decided by the address managing portion, and the access device including a file system control portion which controls the logical addresses of the file data and the file data management information in order to store the file data and the file data management information in different allocation units of the data area and giving the file data, the file data management information and the logical addresses to the nonvolatile memory device.