Hitachi Global Storage Technologies Netherlands B.v.

International Business Machines Corporation

Hirofumi Saitoh

Ryoji Fukuhisa

Takahiro Saito

Atsushi Kanamaru

Hiromi Kobayashi

Tadahisa Kawa

Minoru Hashimoto

Shoichi Hirashita

Shuji Yamada

Masayuki Murakami

Kenji Ogasawara

Hiroshi Oshikawa

Sayaka Nojiri

Hiroyuki Iwasa

Shinji Matsushita

Kayo Takahashi

Naoya Tsurusaki

Shohichi Hirashita

Kazunori Inoue

Embodiments of the present invention improve the safety against a fall of a disk drive device. In one embodiment, when an HDD has recognized detection result data of a fall sensor to indicate a fall, the HDD unloads a head slider from above a disk to a stand-by position. The HDD checks whether or not the detection result data of the fall sensor indicates a fall on the occasion of a seek start. If the data indicates a fall, the controller unloads an actuator. The HDD issues a seek fake error on the occasion of a seek completion. On the occasion of a re-seek start in the error recovery process, the HDD conducts a fall check referring to the detection result data.

Disk drive device and control method of unloading corresponding to fall detection in disk drive device

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

Embodiments of the invention provide a disk device and a method of controlling the device which is capable of suppressing peak current, even for serial communication, that is required when initiating rotation of a spindle motor down to a level equivalent to that of parallel communication, without prolonging elapsed time before reaching the steady rotation speed. In one embodiment, an HDD includes a serial communication circuit which executes serial communication with a host, an SPM which rotates a disk, an HDC/MPU which controls the SPM and the serial communication circuit. The HDC/MPU, after shutting down the serial communication circuit once, starts up the serial communication circuit again when rotation speed of the SPM reached the specified standard value, and establishes serial communication with the host by means of the serial communication circuit.

Disk device for serial communication and method of controlling the same

Embodiments of the invention increase the probability of error recovery in error recovery processing. When a reset command is received during an error recovery procedure (ERP), a timer is started in response to the reset command. From the time at which the reset command has been received until the predetermined time prescribed by the timer passes, the ERP step is continued. After the timer expires, the ERP processing stops on the completion of an ERP step M. Additionally, a HDD returns to a host a reset ready, which represents the completion of the reset. Since the ERP is continued even after the reset command is received, it is possible to increase the probability of error recovery.

Error recovery method for data storage device, data storage device, and magnetic disk storage device

Embodiments of the invention reduce consumption power of a data storage device. In one embodiment, an HDD according to the embodiment selectively switches a serial interface among other circuits to a power-save mode. The HDD receives a command from a host, and, in a command execution sequence thereof, sets and keeps the serial interface in the power-save mode for at least a partial period of time during which no sending and receiving of data resulting from serial data communication with the host exists. Further, in responding to completion of execution of the command, the HDD switches the serial interface to the power-save mode.

Data storage device and control method for power-saving modes of serial interface thereof

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

To avoid degradation of performance of a storage apparatus even when access biased to writing or reading of data is performed in a buffer memory that adopts a dual ring buffer system as a data structure. A sector buffer for caching an access request is provided in a DRAM of the storage apparatus. The sector buffer has a first ring buffer (BUF_W) that temporarily holds an external write request for a recording medium in advance of its process to the recording medium, and a second ring buffer (BUF_R) that retains data read from the recording medium according to an external read request for the recording medium. An MPU of the storage apparatus shifts a BPAGE of the BUF_R or BUF_W according to external access patterns to the recording medium to thereby change the buffer sizes of the BUF_R and BUF_W.

Data storage apparatus and method for managing buffer memory

In a novel method for controlling a disk apparatus having an interface, command storage, and data storage, one or more commands are received from an external apparatus via the interface, and the one or more commands are held in the command storage. A command to be next executed is selected from among the one or more commands and dispatched for execution. It is determined whether an error relating to accessing the data storage has arisen during execution of the selected command. If so, the selected command is restored to the command storage. A subsequent command to be next executed may then be selected. In one described embodiment, an estimated seek time for the selected command is determined, and it is judged that an error has arisen if actual seek time of the selected command exceeds the estimated seek time.

Disk apparatus and control method therefor

Disk drive apparatus and control method thereof

The present invention provides, at a lower cost, a highly reliable data reading method and data reading apparatus that can improve backward sequential reading performance. The disk drive is provided with a magnetic disk and a control section having an HDC, a RAM, an MPU controlling the operation of the entire HDD, including control of the HDC, a ROM, and an I/F for connecting to an external host device. The control section executes a backward reading detection step that detects backward reading, a step of receiving a command that reads a block of a first length from a first LBA, a step that reads a block of the first length from the first LBA when backward reading is detected, and a step that pre-fetches a second block from a second LBA smaller than the first LBA; when backward reading is detected, upon completion of the reading of data from the disk, the reading of data predicted to be requested by the next command begins immediately.

Data reading method and data reading apparatus

Data reading method and apparatus for a disk drive storage device

In a computer system including a host which operates in a pre-read mode to start a block data transfer after reading status of a peripheral device (HDD) in response to an interrupt from the peripheral device or in a post-read mode to read the status after completing the block data transfer, an interface circuit comprising mode detecting circuitry for automatically detecting whether the host operates in the pre-read mode or in the post-read mode so that data transfers can be correctly performed between the peripheral device and the host even if the host is in either mode, delay circuitry for delaying by a predetermined amount of time, a data request DRQ indicating that a block of data is ready to be transferred, when the post-read mode is detected, and interrupt circuitry for sending an interrupt request IRQ to the host in response to the output of the delay circuitry.

Growing community of inventors

Kanagawa, Japan

Hirofumi Saitoh