US 7,444,460 B2Granted

Data storage device, method for updating management information in data storage device, and computer program

AssigneeSony Corporation

InventorsKenichi Nakanishi, Junko Sasaki, Nobuhiro Kaneko, Osamu Nagata, Hideaki Okubo

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Abstract

The invention provides a data storage device and a method of updating management information, capable of dealing with management information in a highly reliable manner so that information is not easily lost when an error occurs. File management information such as a FAT serving as address management information in a flash memory is stored in a management information area of the memory, a pair of blocks is assigned as blocks for use to store data of the FAT, and writing of updated FAT information is performed by alternately using the two blocks of the block pair such that previous FAT information is retained in one of the two blocks of the block pair, and updated FAT information is written in the other block of the block pair, whereby, even when an error occurs in the middle of the process of writing the updated management information, a process using the retained previous FAT information is possible.

Claims14

Dependent claims

A data storage device including a data storage unit and a control unit for controlling inputting and outputting of data to or from the data storage unit, wherein:

the data storage unit is divided into blocks each including a plurality of pages each having a predetermined storage capacity, and the data storage unit includes a data area for storing user data and a management information area for storing management information including address information used to access the data area;
in the management information area, file management information including address concatenation information associated with a data file stored in the data area is stored;
and
the control unit executes a process of writing updated file management information such that:
previous file management information is retained in a page in one of two different blocks forming a block pair, and the updated file management information is written in a page in the other one of the two blocks of the block pair,
wherein the block pair is assigned in advance at the same time interval and comprises an even block and an odd block, and
wherein when previous file management information is written to the even block, updated file management information is written to the odd block, and
wherein the even block and the odd block are then used alternately for storing updated file management information and previous file management information.

5 more elements

A method of updating management information in a data storage device including a data storage unit and a control unit for controlling inputting and outputting of data to or from the data storage unit, the method comprising the steps of:

inputting a logical address corresponding to management information to be updated;
identifying a block pair by acquiring address information of two physical addresses corresponding to the logical address and identifying two blocks indicated by the respective two physical addresses as the block pair to be used to write updated file management information;
writing the updated management information such that previous file management information is retained in a page in one of two blocks of the block pair, and the updated file management information is written in a page in the other one of the two blocks of the block pair;
and
assigning the block pair in advance at the same time interval and such that the block pair comprises an even block and an odd block, and
wherein when previous file management information is written to the even block, updated file management information is written to the odd block, and
wherein the even block and the odd block are then used alternately for storing updated file management information and previous file management information.

4 more elements

Dependencies are inferred from the claim text.