Hitachi Global Storage Technologies Netherlands B.v.

International Business Machines Corporation

Hiroshi Oshikawa

Hideo Asano

Tatsuya Sakai

Masahiko Sato

Hiroshi Uchida

Minoru Hashimoto

Satoshi Yamamoto

Toru Aida

Tetsuya Tamura

Kenji Okada

Atsushi Kanamaru

Keishi Takahashi

Hirofumi Saitoh

Toshio Kakihara

Makoto Takase

Kohji Takasaki

Yasuhiro Kotani

Takayuki Kinoshita

Tsuyoshi Satoh

A head position estimator estimates the present position of a head relative to a recording medium, an LBA calculator for calculating positions of a data block to be read next and other data blocks existing before and after the data block, and a moving destination determiner for determining a data block at which the time required to move the head is the shortest, as a data block to be read next, on the basis of the present position of the head, which has been estimated by the head position estimator, and the positions of the respective data blocks, which have been calculated by the LBA calculator.

Recording and reproducing apparatus, content reproducing apparatus, magnetic disk device, and control method thereof

A file is transferred directly between a parent magnetic-disk device and a child magnetic-disk device. In one embodiment, a parent magnetic-disk device has a host-mode execution program, whereas a child magnetic-disk device is capable operating in a device mode as is the case with an ordinary magnetic-disk device. The parent magnetic-disk device has an operating-mode-setting unit including a special-purpose jumper block. An MPU employed in the parent magnetic-disk device executes the host-mode execution program to put the parent magnetic-disk device in a host mode. At an activation time, the MPU refers to the logic of the special jumper block to start an operation in the host mode. The MPU controls the parent magnetic-disk device to directly transfer a file to the child magnetic-disk device. Thus, the file can be transferred between the parent and child magnetic-disk devices without intervention by a host computer.

Storage devices and method of transferring file between the devices

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 invention provide an interface circuit that is capable of reducing the power consumption, which may be increased by a shoot-through current, and provide an electronic device having such an interface circuit. In one embodiment, an interface circuit exchanges signals with another electronic device via a signal transmission line. The interface circuit includes a switch for pulling up the signal transmission line and a switch for pulling down the signal transmission line. While a pull-up or pull-down is performed, the interface circuit detects the potential level of the signal transmission line to determine whether the signal transmission line is pulled down or pulled up by the other electronic device. If the signal transmission line is not pulled down/pulled up by the other electronic device, the interface circuit exercises pull-down/pull-up control.

Interface circuit power reduction

The signal output device of the present invention comprises of a driver circuit and a controller. The signal sending method of the present invention sets any one of a plurality of the different sending rates. The method also includes setting a slew rate of the driver circuit to a standard value that is in accordance with the predetermined data transfer rate, thereby starting signal transmission. The next step involves determining whether or not a data transfer error occurrence rate is below a predetermined allowable threshold. Then, changes in the slew rate of the driver circuit are made if the data transfer error occurrence rate is determined to be over the allowable threshold. Next, a search for a slew rate value that can decrease the data transfer error occurrence rate below the allowable threshold or decrease the data transfer error occurrence rate is performed. The new slew rate value is set as a new standard value. Finally, the process ends by setting the new standard slew rate for the driver circuit if the slew rate value can decrease the data transfer error occurrence rate below the allowable threshold or decrease the data transfer error occurrence rate.

Signal output device and method for sending signals at multiple transfer rates while minimizing crosstalk effects

Methods and apparatus are described for a data transfer unit between a storage unit and a host, wherein a slower data transfer rate is established when a predetermined error is detected. In one embodiment the cyclicity of the error occurrence calculated and a wait is inserted between data to avoid transferring data at the calculated cyclicity point of the detected error. Optionally the data transfer unit may return the data transfer rate to the original data transfer rate or state after a predetermined time has elapsed, after a predetermined number of commands have been received, after a predetermined amount of data have been transferred, or by combination of these.

DMA transfer from a storage unit to a host using at least two transfer rates and cyclic error detection

Growing community of inventors

Kanagawa, Japan

Hiroshi Oshikawa