Hitachi Global Storage Technologies Netherlands B.v.

Hgst Netherlands, B.v.

Tadahisa Kawa

Atsushi Kanamaru

Hiromi Kobayashi

Hirofumi Saitoh

Takahiro Saito

Donald Joseph Molaro

Jorge Campello De Souza

Damien C D Le Moal

Frank Rui-Feng Chu

Tsuguaki Kowa

A data storage device accepts queued read and write commands that have deadlines. The queued read and write commands are requests to access the data storage device. The deadlines of the queued read and write commands can be advisory deadlines or mandatory deadlines.

Data storage devices accepting queued commands having deadlines

Embodiments of the present invention provide a media drive that is intended for reduction in power consumption required for serial communications to/from a host, and a power saving method thereof. In one embodiment, a HDD includes: a cache; a host interface for transferring, to a host, transfer data read out from the cache; a host interface manager that controls the execution of commands so as to generate a transfer unnecessary period during which a command and transfer data need not be exchanged with the host; and a MPU that brings a serial communication part of the host interface into a power save mode during the transfer unnecessary period. The host interface manager determines the optimum data transfer timing of transferring data from the cache to the host on the basis of a transfer rate at which data is transferred to the host, and a read rate at which data is read out from a disk into the cache.

Media drive that creates a transfer unnecessary period, and power saving method thereof

Data in a nonvolatile memory included in a data storage device is rewritten with higher security. According to one embodiment of the present invention, if an error is included in data stored in a nonvolatile semiconductor memory, the HDD rewrites correct data to the nonvolatile semiconductor memory. In particular, during the execution sequence of a write command, the HDD executes rewrite processing of control data stored in the nonvolatile semiconductor memory. More specifically, data is rewritten during a specified period of time that falls within a period of time starting from a start notification of write-data transfer processing that is sent from the HDD to the host, until a command completion notification. Since there is a very small possibility that the power of the host may be interrupted during this specified period of time, it is possible to securely rewrite data.

Data storage device, and method for rewriting data in nonvolatile memory

Embodiments of the present invention provide a media drive capable of improving command processing performance by, when a plurality of commands is queued, shortening seek time and rotational latency, and also effectively making use of the shortened period of time. In one embodiment, a HDD includes a queue capable of storing a plurality of commands, and a queue manager for optimizing the execution order of the plurality of commands on the basis of whether or not the execution of each command requires access to a medium. The queue manager determines the execution order so that medium access processing of accessing a disk for execution, and data transfer processing of transferring data between the HDD and a host, are executed in parallel with each other. For example, read processing and transfer processing are executed in parallel with each other. The read processing is adaptive to read out a read command, data of which does not exist in the cache, from the disk into the cache. The transfer processing is adaptive to transfer a read command, data of which exists in the cache, to the host.

Media drive and command execution method thereof

Growing community of inventors

Kanagawa, Japan

Tadahisa Kawa