Kabushiki Kaisha Toshiba

Toshiba Memory Corporation

Katsuyuki Nomura

Akihisa Fujimoto

Keiri Nakanishi

Sho Kodama

Tomoya Kodama

Takayuki Itoh

Youhei Fukazawa

Kojiro Suzuki

Kazuki Inoue

Kenichi Douniwa

Harutaka Goto

According to an embodiment, a storage controller comprises a circuitry configured to implement an address generator, a reader, and a duplication detector. The address generator is configured to generate a scan address indicating each storage area of a storage that stores therein externally written data, according to a particular scan pattern for defining an order of an address of data to be read. The reader is configured to read data from the storage area of the storage indicated by the scan address. The duplication detector is configured to detect whether the data read by the reader is a duplicate of any one of a past predetermined number of pieces of data.

Storage controller, storage device, data processing method, and computer program product

According to an embodiment, a storage control device includes a controller, a compression condition determiner, a compressor, and an error correction encoder. The controller receives a write request for a data item and determines whether or not the wear degree of a target region in a storage device to which the data item is to be written is less than a threshold value. The compression condition determiner determines, based on the wear degree, an optimal compression condition out of compression conditions that include lossy compression. The compressor generates, based on the compression condition, compressed data. The error correction encoder subjects the data item to error correction and generates encoded data.

Storage control device, storage system, and storage control method

A controller writes, after writing data into a nonvolatile memory unit, new management information that reflects the data wiring, into an area of the memory unit other than an area of the nonvolatile memory unit, which stores last management information. After that, the controller writes an old management information flag in relation to the last management information. Further, the controller searches the memory unit for updated, normal management information when initializing the memory system. If it does not find updated, normal management information, the controller restores updated management information on the basis of normal old management information related to the old management information flag.

Controller for controlling nonvolatile memory unit

A rewritable nonvolatile memory comprises a block usage control table indicating a usage status of each block of the nonvolatile memory. When the data is written, it is determined whether or not the data is correctly written. If it is determined that the data is not correctly written, the block address is stored as a candidate address of a defective block and writing operation is performed for another block. If it is determined that the data is correctly written, the block usage control table is updated such that the usage status of the candidate of a defective block and the present block is changed to a used status.

Nonvolatile memory and method of writing data thereto

Logical block addresses are allocated to the blocks provided on a flash memory, respectively. Address translation tables (LTPb's) are provided on the flash memory, each for a group of blocks. Groups of logical block addresses are provided, each group for one group of blocks provided on the flash memory. The logical block addresses of each group have a specific field each. The same data item is contained in the specific fields of the logical block addresses of any group. The data item designates all blocks of the group corresponding to the group of the logical block addresses. Each table has a group of entries storing physical address information indicating the locations that the blocks take in the flash memory. At least one of the tables is stored on a RAM. When a logical address is given from a host system, a microprocessor determines whether a table corresponding to the logical address exists on the RAM. If such table does not exist, the table is copied from the flash memory to the RAM. The microprocessor refers to the corresponding entry in the table on the RAM in accordance with the logical block address contained in the logical address, thereby performing translation from a logical address to a physical address.

Growing community of inventors

Hino, Japan

Katsuyuki Nomura