Kabushiki Kaisha Toshiba

Toshiba Electronic Devices & Storage Corporation

Syosuke Maruyama

Kana Furuhashi

Yosuke Kondo

Hideo Shimokawa

According to the embodiment, an HDC receives a plurality of data segments from a host, and executes generation and addition of a first code and output of a data segment to which the first code is added to each data segment. An HDC calculates exclusive OR with respect to the first codes, and outputs obtained first information. The RWC performs data conversion and calculation of exclusive OR on the plurality of data segments to which the first code is added, and outputs the plurality of data segments after the data conversion and a track parity obtained by the calculation of the exclusive OR. The RWC acquires the first code from the plurality of data segments. The RWC calculates exclusive OR with respect to a group of the second codes which are the acquired first codes to acquire second information. The RWC compares the first information with the second information.

Magnetic disk device

According to an embodiment, on a first track of a magnetic disk, a plurality of first sectors in each of which a data segment is stored, and a second sector in which a parity for first error correction is stored are arranged in this order from a first position. A controller executes a first operation of sequentially reading a first data segment from each of the plurality of first sectors, and storing a group of the read first data segments in a buffer memory. The controller obtains a first parity from the group of the read first data segments. The controller starts a second operation of writing each first data segment stored in the buffer memory, to a first sector that is a read source among the plurality of first sectors, and writing the first parity to the second sector, before the magnetic head reaches the first position.

Magnetic disk device and method for suppressing time required for rewrite operation caused by adjacent track interference

According to an embodiment, a track includes first sectors and a second sector. When write of a second data segment to a third sector that is one of the first sectors is requested from a host, a controller acquires the second data segment from the host and stores the second data segment in the memory, and reads a data set including all first data segments and all first information pieces from the track and stores the data set in the memory. The controller acquires a second information piece of the third sector, and updates a first data segment and a first information piece read from the third sector in the data set in the memory with the second data segment and the second information piece. The controller calculates a second parity while the updated data set to the track, and writes the second parity to the second sector.

Magnetic disk device and method

A magnetic disk device includes a plurality of tracks and a controller. The controller receives write data to be written to a first sector of a track, generates a first data string based on the write data and a logical identifier for the first sector, attempts to cause the first data string to be written to the first sector, determines whether a write error has occurred while the first data string is written to the first sector, generates a second data string based at least in part on the first data string, and in response to determining that no write error has occurred while the first data string is written to the first sector, writes a parity data string that is based at least in part on the second data string to a second sector of the track that stores parity data for the track.

Magnetic disk device configured to write parity data that is based on data being written to a parity sector when no error is detected in writing the data being written

A disk device includes a recording medium on which data is recorded, a decoding circuit configured to decode data read from the recording medium, and a control circuit. The control circuit is configured to cause first data associated with a target sector referenced in a read request to be read from a target track of the recording medium, second data associated with a non-target sector that is not referenced in the read request to be read from the recording medium after the first data is read from the recording medium, and decoding of the first data to be completed by the decoding circuit after the second data is read from the recording medium.

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Machida Tokyo, Japan

Syosuke Maruyama