Seagate Technology Incorporated

Other

Anish A Ukani

Karl Louis Enarson

Timothy Ted Walker

Daniel Eugene Hobson

Ronald D Metzner

John Edward Moon

Lealon Ray McKenzie

Robert Matousek

Paul Francis Kusbel

David R Street

Paul William Burnett

John M Baker

Ronald L Delamarter

Raymond Dean Nicholson

Kent Dillin

Method and apparatus for monitoring temperature

A method and apparatus are disclosed for optimizing operational performance of a disc drive. The disc drive is provided with an integrated temperature measurement circuit which provides a temperature measurement signal indicative of operational temperature of the disc drive. The integrated temperature measurement circuit is formed as part of an application specific integrated circuit (ASIC) housing additional circuitry used by the disc drive during operation. A parametric configuration circuit, operably coupled to the integrated temperature measurement circuit, identifies selected parameters for use by the disc drive to optimize disc drive performance, the parameters arranged as a plurality of parameter sets corresponding to a plurality of predefined operational temperature ranges. The parametric configuration circuit periodically measures the operational temperature of the disc drive through evaluation of the temperature measurement signal, identifies the operational temperature range in which the measured operational temperature falls, and implements the parameter set corresponding to the identified operational temperature range.

Integrated temperature sense circuit in a disc drive

Method and apparatus for predicting future failure of a disc drive head from degradation in a head readback response characteristic, such as electrical resistance, readback signal amplitude, asymmetry or nonlinearity. During manufacturing, the disc drive determines and store a baseline level for a selected readback response characteristic of the head indicative of head performance as data are read back from a disc. During subsequent data processing use, the disc drive subsequently periodically determines a subsequent level for the readback response characteristic of the head. The possibility of a future failure of the drive is next predicted in relation to a difference between the baseline level and the subsequent level for the readback response characteristic of the head. An indication of the possibility of the future failure is provided to allow a host device to reallocate data stored on the disc before the failure of the head.

Detecting head readback response degradation in a disc drive

A method and apparatus are disclosed for optimizing operational performance of a disc drive through temperature dependent parametric configuration. A plurality of parameter sets corresponding to a plurality of predefined contiguous operational temperature ranges of the disc drive are initially established. During operation of the disc drive, a temperature sensor is used to periodically measure the temperature of the drive. The operational temperature range in which the measured temperature falls is identified, and the disc drive utilizes the parameter set corresponding to the identified operational temperature range.

Temperature dependent disc drive parametric configuration

Method and apparatus for improving the operational response of a disc drive. Compensation routines are performed to adjust disc drive parameters in accordance with existing environmental conditions during an idle mode of operation of the drive. At such time that a selected, uninterrupted amount of time passes since the most recently performed disc drive operation, the disc drive enters the idle mode and performs a predetermined sequence of the compensation routines, after which the disc drive performs dithering in which heads of the disc drive are positioned about various locations with respect to the corresponding discs of the disc drive. A compensation table is provided setting forth the predetermined sequence of the compensation routines and the table is reordered so that the compensation routines are subsequently performed in a different sequence.

Disc drive operational response using idle mode compensation

Apparatus and method for detecting defective servo frames in a disc drive, the defective servo frames including anomalous position field patterns which generate burst signals of insufficient relative magnitude to facilitate proper servo control. Burst signals are generated from the position field patterns of a selected servo frame and a combination term is determined as a selected combination of the magnitudes of the burst signals. The combination term is compared to a predetermined threshold and the servo frame is identified as being defective when the combination term falls below the predetermined threshold. The combination term is preferably generated from the magnitudes of burst signals generated from three burst patterns: a first burst pattern extending from a first track boundary to a second, adjacent track boundary, a second burst pattern extending from a track centerline to the first track boundary and a third burst pattern extending from the track centerline to the second track boundary.

Servo frame defect mapping in a hard disc drive

A method for calibrating the position error signal in a servo system of a disc drive. The disc drive comprises a disc and an actuator adjacent the disc, the actuator including a head which is controllably positionable relative to data tracks on the surface of the disc using a servo position error signal generated using a scale factor generally indicative of the ratio of the width of the head to the width of the tracks on the disc. The head is positioned at the center of a selected track using an initial scale factor for the position error signal, the selected track having servo position fields comprising a plurality of burst patterns. The burst patterns include a first burst pattern extending radially from a first track boundary to a second track boundary of the selected track, a second burst pattern extending radially from the center of the selected track to the first track boundary and a third burst pattern extending radially from the center of the selected track to the second track boundary. At the center of the selected track, the magnitude of burst signals read by the head from the second and third burst patterns is nominally equal, and from this location the head is swept towards the first track boundary until the magnitude of burst signals from the second burst pattern is nominally equal to the magnitude of burst signals from the first burst pattern, identifying a quarter-track location halfway between the center of the selected track and the first track boundary. A calibration scale factor for the position error signal is determined from the ratio of the expected position error signal to the actual position error signal obtained at the quarter-track location. Alternatively, the initial scale factor is incremented and the head is repositioned towards until the quarter-track location until the magnitude of burst signals from the second burst pattern is nominally equal to the magnitude of burst signals from the first burst pattern, after which the incremented scale factor is stored as the calibration scale factor.

Servo position error signal calibration in a hard disc drive

Method and apparatus for optimizing the read/write channel error recovery process in a disc drive. An error recovery table comprising a plurality of sequentially ordered corrective operations is provided so that, upon receipt of an error from the disc drive read/write channel, the corrective operations are sequentially performed in an attempt to correct the error. At such time that a selected one of the corrective operations results in the correction of the error, the table is reordered so that the selected one of the corrective operations is advanced in the table sequence, and the reordered table is used upon the occurrence of the next error. Additionally, a series of free retries is performed prior to the operation of the error recovery table.

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Oklahoma City, OK, United States of America

Anish A Ukani