Marvell International Limited

Hitachi Global Storage Technologies Netherlands B.v.

Marvellworld Trade Ltd.

Marvell Technology Japan Y.k.

Minoru Tsukada

Soichi Isono

Tomoki Oura

Koji Takahashi

Hiroyuki Kimura

Yoshikatsu Fujii

Tomoki Ooura

An apparatus includes, in at least one aspect, a plurality of buffers and circuitry configured to store encoded data in one buffer of the plurality of buffers concurrently with storing other data in another buffer of the plurality of buffers and to write the stored encoded data from the one buffer to a storage device concurrently with storing encoded other data in the other buffer, replacing the stored other data in the other buffer.

Magnetic disc controller and method

A method includes, in at least one aspect, receiving a data set to be written onto a medium, identifying an index associated with the medium, identifying a first sector and a second sector of the medium, the first sector preceding the second sector, generating an error code for the data set based on the index and the first sector, and writing at least one of the data set or the generated error code into the second sector.

Writing data to a storage medium

Methods and apparatus describe processing of data for recording to a storage device. An apparatus includes, in at least one aspect, a plurality of buffers and circuitry configured to encode data stored in one buffer of the plurality of buffers concurrently with storing data in another buffer of the plurality of buffers and to write the encoded data from the one buffer to a storage device concurrently with encoding the stored data in the other buffer.

Processing data for recording to a storage device

A magnetic disk controller includes an error check code generating unit that generates error check codes associated with the encoded pieces of writing data; a first buffer that stores a first encoded piece of writing data and a first error check code associated with the first encoded piece; a second buffer that stores a second encoded piece of writing data and a second error check code associated with the second encoded piece; and a buffer control unit that, in a first period, substantially concurrently with a writing of the first encoded piece and the first error check code from the first buffer into a first sector of the magnetic disk, stores the second encoded piece and the second error check code into the second buffer.

Systems, methods and computer program products for writing and reading a plurality of data sets and error codes are described. In some implementations, a magnetic disk controller can be provided that includes an error code unit configured to generate one or more error codes for each of a plurality of data sets to be written onto corresponding sectors of a medium. The magnetic disk controller can also include a buffer unit configured to store each data set and an error code in an associated buffer, and an encoding unit configured to encode the plurality of data sets. In some implementations, at least one data set is encoded concurrently with the buffer unit storing another different data set in the associated buffer. The magnetic disk controller can also include a control unit configured to write each encoded data set and a corresponding error code onto a corresponding sector.

Magnetic disk controller to process plural data sets for recording onto a medium

Among other disclosed subject matter, a magnetic disk controller can include an index detecting unit to detect an index of the magnetic disk, an error check code generating unit to, after the index detecting unit detects the index, generate a first error check code for first write data based on the first write data and a first physical address of a first sector subsequent to the detected index, and a writing control unit to cause the first error check code generated by the error check code generating unit, the first write data and the first physical address to be written into a second sector subsequent to the first sector.

Magnetic disk controller and method

A magnetic disk controller includes a first buffer that includes a first storage area that stores former portions of pieces of writing data, and a second storage area that stores latter portions of pieces of writing data; an encoding unit that encodes a former portion of the first piece of writing data; a second buffer that stores the encoded former portion of the first piece of writing data; and a buffer control unit that writes the encoded former portion of the first piece of writing data into a first sector of the magnetic disk. The encoding unit encodes the latter portion of the first piece of writing data. The second buffer stores the encoded latter portion of the first piece of writing data. The buffer control unit, writes the encoded latter portion of the first piece of writing data into the first sector of the magnetic disk.

Embodiments of the present invention provide a magnetic disk drive capable of controlling write/read positions by a method that takes the disturbance in the circumferential direction of a magnetic disk into consideration, thereby making it possible to improve the positioning accuracy. A magnetic disk drive in accordance with an embodiment of the present invention comprises: a magnetic recording medium on which information is written to each track thereof, the recording medium having a servo signal formed in the each track at specified intervals; a magnetic head including a read head for reading a signal from the magnetic recording medium, and a write head for writing information to the magnetic recording medium. At the time of writing/reading information by the magnetic head, a servo signal is detected from among signals read out by the read head. Information about intervals of the detection is continuously acquired on the basis of the information about the servo-signal detection intervals that have been continuously acquired. The amount of rotational fluctuations of a magnetic disk is calculated; and if the amount of rotational fluctuations exceeds the predetermined allowable range, specified processing relating to at least one of writing and reading is stopped.

Magnetic disk drive

Among other disclosed subject matter, a magnetic disk controller includes an interface that receives and transmits data to be written into a magnetic disk. The magnetic disk controller includes a first buffer and a second buffer each of which temporarily stores data that is to be written into at least one sector of the magnetic disk. The magnetic disk controller includes an encoding unit that encodes the data stored in any of the first buffer and the second buffer into data representing a signal to be applied to the magnetic disk. A data width M between the encoding unit and the first and second buffers is at least equal to twice a data width N between the interface and the first and second buffers.

Embodiments of the invention eliminate the unnecessary disk format margin to raise the format efficiency. In one embodiment, a disk control unit (MPU) predicts the variation of the next servo sector pulse interval based on each learnt servo sector pulse interval. From this predicted interval, an optimal variation of the data sector pulse interval is determined for the current servo sector pulse. This optimal variation is set to an internal register of the hard disk controller (HDC). Based on this set variation, an internal calculation circuit calculates a corrected data sector pulse interval. Thus, data sector pulses are output at intervals optimized on an individual servo sector basis.

Growing community of inventors

Kanagawa, Japan

Minoru Tsukada