Seagate Technology Incorporated

Other

Jimmie Ray Shaver

Sean R Atsatt

Barmeshwar Vikramaditya

Prafulla Bollampalli Reddy

William K Weberg

Timothy V Gates

Shawn Alan Wakefield

Brett Alan Sloan

Mark Hubert Groo

Mark A Gaertner

Bernardo Rub

Brian Thomas Edgar

Stephen R Genheimer

Mark Alan Heath

Clifton James Williamson

Robert D Cronch

Peter Igorevich Vasiliev

Kenneth R Burns

Kenneth Lawrence Barham

Bang Cong Nguyen

Mark H Groo

Dhiru N Desai

Pervez Edul Virjee

Robert William Warren, Jr

Gary W Reininga

Srinivas Maddali

Wuping Chen

Kavi Alptekin

The defined architecture allows for format-efficient data storage on bit-patterned media, while allowing for typical variations in the drive, such as reader to writer gap variations. The defined BPM architecture relaxes some timing requirements on real-time signaling from the formatter to the channel, while enabling bit-accurate alignment between data accesses and the media.

Data access formatter

Data format that allows for format-efficient data storage, particularly on bit-patterned media. The data format allows for variations in the data storage device, such as reader-to-writer gap variations. A medium can also have at least a pair of a synchronization field and a quiet field with a length greater than a length of the synchronization field. These can be implemented in a bit patterned media system.

Quiet field and synchronization field data format

A data format that allows for format-efficient data storage, particularly on bit-patterned media. The data format uses an intersector gap that is dimensioned relative to a physical dimension of a transducer. Further described is a data storage medium comprising transducer overhead, such as an intersector gap, interleaved with fragment overhead. Also described is a storage medium comprising intersector gaps that each include a write splice and extra symbols.

Data intersector gaps for data sector format

Apparatus and methods are disclosed that adjust the phase of a read/write clock signal. The read/write clock signal may be used in a data storage apparatus to regulate reading/writing on a data storage media. An apparatus includes an adjustment circuit that adjusts phase of an edge of a read/write clock signal based on the timing of information that is read from a data storage media. Another apparatus includes a servo circuit and a read/write channel circuit. The servo circuit generates a leading edge transition of a servo gate signal in response to a signal indicating that a read/write transducer is approaching a start of a servo wedge. The read/write channel circuit generates a trailing edge transition of the servo gate signal in response to occurrence of a defined time delay following the transducer reading a servo address mark from the servo wedge.

Adjustment of read/write clock edge timing

A system and method for accessing data stored on surfaces of discs in a disc drive utilizing more than one serpent per recording zone. The serpents are traversed using a defect descriptor table and one or more physical zone tables (PZTs). An Address Translation Logic Unit is configurable to use one or more PZTs to access multiple serpents per recording zone.

Physical zone table for use with surface-based serpentine format

A method and apparatus for an error-correction buffer having self-throttling data burst control in a disc drive. One aspect of the present invention provides an arbitration-throttling control circuit for use in a disc drive to self-throttle the data transfer of an error-correction buffer. The arbitration-throttling control circuit includes a control circuit having an error-correction buffer interface and a disc-drive main buffer memory interface for controlling data transfer from the error-correction buffer to a disc-drive main buffer in a plurality of data bursts. The control circuit arbitrates for access to transfer data into the disc-drive main buffer such that a series of data bursts from the error-correction buffer to the disc-drive main buffer are spread substantially evenly over a period of time.

Self-throttling error-correction buffer and method for a disc drive

An apparatus and method are disclosed for improving data recovery operations in a disc drive employing a redundant sync data block format. The disc drive includes a rotatable disc and a controllably positionable head which is used to store user data in a plurality of data blocks on tracks of the disc. Each data block includes a user data field to store user data, a first sync field and a redundant, second sync field, the sync fields storing first and second sync words, respectively, which establish symbol boundaries used by a read channel of the disc drive. User data are recovered from a selected data block by initiating a delay of selected duration during which a first portion of the selected data block passes proximate the head, allowing the second, remaining portion of the selected data block to be read at the completion of the delay. Data can thus be recovered in the presence of mis-sync errors, wherein a selected sync word is detected early or late by one or more bits, as well as from non-contiguous data blocks that are split into two fragments to accommodate a coincident servo block.

Data recovery in a disc drive with redundant sync data blocks

Embodiments of the present invention illustrate various configurations of a channel-to-controller interface. In one embodiment, width of symbols crossing the interface is fixed, as is the clock rate. In other embodiments, the symbol width is variable, and the clock rate is also varied based upon the size of the interface symbol width and the operation of the channel.

Configuration of channel-to-controller interface in a disc drive

A memory medium has a plurality of tracks arranged in a plurality of sectors with each track sector having a format which does not include header fields identifying sectors or sector defects or defect management procedures. Track management apparatus identifies the track sector currently confronting a transducer; the track management being based on sector pulses (in the case of a dedicated servo system), or being calculated based on track information, an index pulse and data wedge information from previous wedges (in the case of embedded servo systems), or being derived from a lookup table. To accommodate sector defects, a defect bank contains the identity and type of each defective or spare sector. Defect management apparatus is connected to the defect bank and track management apparatus to indicate when the sector confronting the transducer is a defective or spare sector to halt data transfer to thereby skip the defective sector, or to generate an interrupt signal to the processor to transfer data between the processor and an alternate sector.

Apparatus and process for identifying sectors in a headerless sector data track

Read error recovery utilizing ECC and read channel quality indicators

An address translation unit is provided for logical to physical address conversion. In particular, apparatus and method are described for receiving a logical cylinder head sector for a logical block address and converting it into a physical cylinder head sector. If a logical block address is received, it is converted to a physical block address and then the physical block address is converted into a physical cylinder head sector. If a logical cylinder head sector is first received, it is converted into a logical block address, and then the conversion takes place just as it would for an initially received logical block address.

Autonomous high speed address translation with defect management for

Apparatus and process for managing defective headerless sectors

A data transfer circuit for coordinating transfer of data between a host and a disc of a disc drive having a state machine for coordinating with a buffer controller to transfer data between the host and a buffer segment and a second state machine for coordinating with the buffer controller to transfer data between the buffer segment and a disc of the disc drive. Counting circuits count the number of bytes transferred between the host and the buffer segment and between the buffer segment and the disc and provide sector count signals each time a sector of data is transferred into or out of the buffer segment. The sector count signals are received by a buffer manager which includes counters for counting sectors of data transferred into and out of the buffer segment and a comparator circuit that compares the contents of the buffer manager counters to provide a code indicative of the state of the buffer segment to a decoder. The decoder provides pause signals to the state machines to suspend data transfers from the source, host or disc, of data when the buffer segment is filled to capacity and to suspend transfers to the receiver, host or disc, of the data when the buffer contains no data which has not been previously transferred to the receiver.

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Yukon, OK, United States of America

Jimmie Ray Shaver