Seagate Technology Incorporated

Richard Lyle Keizer

Mehmet Fatih Erden

Timothy Francis Ellis

Alexei Hiram Sacks

Puskal Prasad Pokharel

Mustafa Can Ozturk

Barmeshwar Vikramaditya

Mehmet Faith Erden

Patrick J Korkowski

In a servo control loop, servo burst signals that are read from a plurality of servo burst patterns that include a split servo burst pattern contain frequency acquisition error. The frequency acquisition error is at least partially removed to generate a frequency acquisition error compensated position error signal (PES).

Reducing effect of frequency acquisition error in a position error signal responsive to split servo burst patterns

In a servo control loop, phase detection between a clock signal and servo burst fields on a movable storage media is carried out with compensation for the effects of frequency variation in the timing of servo burst fields.

Phase detector that compensates for frequency variation induced bias in phases of servo burst fields

A method includes estimating a phase difference between components of a position signal in a servo position estimation system, and correcting the phase difference of the components of the position signal to provide a phase-compensated position signal.

Deterministic phase mismatch correction in servo position estimation systems

A servo system for detecting and demodulating servo data is disclosed. In illustrated aspects, a demodulation circuit or portion includes a correlator component configured to output a correlation of a sequence of equalized channel samples with a sequence of correlator weight derived based on at least one mapped channel sequence. A decision component, for example a threshold detector uses the correlation results to output a data bit symbol based upon the correlation of the sequence of equalized channel samples to the at least one mapped channel sequence.

Detection of servo data for a servo system

An apparatus comprises a data storage medium having a plurality of servo sectors and a plurality of data sectors, wherein each of the servo sectors includes a phase locked loop field and a track identification field, a controller for controlling the position of a recording head with respect to the data storage medium, and a servo demodulator for recovering timing information from both the phase locked loop field and the track identification field, and for producing a timing estimate. The method performed by the apparatus is also included.

Utilizing track identification fields for timing recovery

In a method for generating a confidence level of a position error signal (PES) component that is indicative of a quality of the PES component, a PES component is generated using position signal samples of a read back signal corresponding to a servo burst pattern. Next, a noise level corresponding to noise in the read back signal is extracted using the position signal samples. A confidence level is then generated based on the PES component and the noise level. A system for performing the method includes a transformation block, a position error signal (PES) component extractor, a noise extractor, and a confidence level generator. The transformation block is configured to receive position signal samples of a read back signal corresponding to a servo burst pattern taken at a sampling frequency. A transformed domain representation of the position signal samples is then generated by the transformation block based on the sampling frequency and the servo burst pattern. The PES component extractor is configured to extract a PES component of a PES based on the position signal samples. The noise extractor is configured to extract a noise level from the transformed domain representation. The confidence level generator is configured to generate a confidence level that is indicative of a quality of the PES component based on the PES component and the noise level.

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Minnetonka, MN, United States of America

Richard Lyle Keizer