Panasonic Intellectual Property Management Co., Ltd.

Panasonic Corporation

Shigekazu Kogita

Toshiyuki Honda

Hirokazu So

Manabu Inoue

Masahiro Nakamura

Shinji Inoue

Takuji Maeda

Masayuki Toyama

Makoto Ochi

Seiji Nakamura

Masato Suto

Hiroki Etoh

Kunihiro Maki

A memory controller includes: a memory that holds a physical block counter including the number of erase times, a logical block counter including the number of write times, and a logical-physical conversion table; and a control unit that writes data to any physical block address. When the control unit receives a writing data instruction, the control unit updates the number of write times corresponding to the write destination logical block address, if the number of write times corresponding to the write destination logical block address is large, the control unit allocates to the write destination logical block address a physical block address with the number of erase times which is small among spare blocks not allocated to the logical block addresses in the logical-physical conversion table, updates the number of erase times corresponding to the allocated physical block address, and updates the logical-physical conversion table.

Memory controller which effectively averages the numbers of erase times between physical blocks with high accuracy

A non-volatile storage device of the present disclosure includes non-volatile memory configured to have a plurality of areas for storing data, and a memory controller configured to write the data to the non-volatile memory and to read the data from the non-volatile memory. The memory controller includes a memory interface (I/F) connected to the non-volatile memory, a threshold calculator calculating a threshold for the number of error bits of the data based on a storage condition in the case of storing the data in the non-volatile memory without power, and a refresh controller determining whether refresh processing of the data is necessary, based on the threshold and the number of error bits of the data, and executing the refresh processing of the data if the refresh processing of the data is necessary.

Non-volatile storage device, non-volatile storage system, and memory control method with a refresh processing of a data

It is possible to accurately detect a physical block which has caused a fixture defect in a flash memory so as to limit the use of the physical block. By recording a history of generation of a physical block error and a history of physical erasing in an ECC error record, it is judged whether the error which has occurred is accidental or caused by a fixture defect. When no error is caused in the data written by physical erasing after a first read error occurrence, the first error is accidental and if another error is caused, the error is judged to be caused by a fixture defect. By using such an ECC error record, it is possible to accurately judge whether the error is accidental or caused by a fixture defect. By eliminating use of the physical block judged to have a fixture defect, it is possible to reduce read errors.

Nonvolatile storage device, memory controller, and defective region detection method

Provided is a method that, in the case of managing areas of a non-volatile memory of an information recording module by a file system, increases the speed of processing for writing file data and file system management information, and furthermore prevents a decrease in the rewriting lifetime of the non-volatile memory. The information recording module () is provided with a page cache control unit () that stores page cache information () in the non-volatile memory () of the information recording module () and performs control such that a specific physical block is used as a cache when writing small-sized data. Also, an access module () is provided with a page cache information setting unit () that sets information necessary for page cache control in the information recording module (). The combination of the access module () and the information recording module () prevents the execution of needless saving process with use of page caching when writing small-sized data, thereby increasing the speed of writing processing.

Access device, information recording device, controller, and information recording system

A nonvolatile memory device () includes a plurality of physical blocks, each of which is provide with a nonvolatile memory (), a logic/physical address conversion table, a temporary block and a temporary table. The nonvolatile memory () includes a plurality of pages which are predetermined writing units, respectively. The logical-physical address conversion table () stores correspondence information between logic addresses and physical addresses of data to be stored in the physical blocks. The temporary block is a physical block to store data that are smaller in size than those of the page. The temporary table () stores correspondence information between logic addresses and physical addresses with respect to data to be stored in the temporary block.

Nonvolatile memory device including a logical-to-physical logig-to-physical address conversion table, a temporary block and a temporary table

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Osaka, Japan

Shigekazu Kogita