Maxtor Corporation

Eduardo Gentile Veiga

Peter A McEwen

Ara Patapoutian

Bruce Douglas Buch

Jeffrey Lee Sonntag

Ke Han

Bill Richard Baker

Patrick J Moran

Stan Shepherd

Andrew Bishop

Tim Everett

Murat Erkocevic

Mike Moser

A method and system for self-servo writing a disk drive by transferring a servo reference pattern by magnetic printing onto at least one storage surface of a reference disk, wherein a resulting printed reference pattern includes embedded servo information providing servo timing and transducer head position information; assembling the disk drive including the steps of installing at least said disk into the disk drive and enclosing said disk and the data transducers within a housing sealed against particulate contamination from an eternal ambient environment; reading the printed reference pattern from said disk via at least one transducer head to generate a readback signal; sampling the readback signal at a sampling rate to generate a sampled signal; processing the sampled signal waveform specturm to generate a recovered signal including the embedded servo information and a fundamental frequency of the sampled signal; using the servo information from the recovered signal to precisely position and maintain the data transducers at concentric track locations of disk storage surfaces; and self-writing disk drive servo patterns onto the storage surfaces at the concentric track locations with the data transducers in accordance with disk drive servo pattern features.

Self-writing of servo patterns in disk drives

Adjusting a clock signal includes receiving a data stream, detecting a bit in the data stream using a first amount of data in the data stream, adjusting the clock signal based on the detected bit, detecting the bit in the data stream using a second amount of data in the data stream, the second amount of data comprising more data than the first amount of data, and correcting the clock signal if a result of initial detecting differs from a result of subsequent detecting.

System and method for clock adjustment by subsequently detecting a target bit of data stream, re-adjusting, and correcting clock based on difference in detected bit

Sampling data with wide bi-phase code symbols includes sampling a wide bi-phase code symbol in the data a number (N) of times to produce samples of data, selecting a subset of the samples, determining which sample in the subset of samples has a largest magnitude, and selecting a subset of samples in a subsequent wide bi-phase code symbol based on a sample in a previous subset that has the largest magnitude.

Asynchronously sampling wide bi-phase codes

An all digital timing loop is employed in a hard disk drive read channel for improved timing performance. Synchronizing the read channel to a sinewave preamble pattern at the beginning of a servo or data read operation is accomplished by first determining an accurate initial estimate of phase angle, and loading that phase value into the digital phase lock loop phase interpolator without having to halt and restart the sample clock. The timing loop synchronizes to the preamble input pattern very quickly so that timing overhead is reduced. The initial phase estimate is formed by accumulating even and odd ADC samples over a selected integration period, and using those values to access an arctan lookup table. Since ratios of even and odd ADC samples are used, gain variations and other analog tolerance issues are avoided.

Digital zero-phase restart circuit

Growing community of inventors

Sunnyvale, CA, United States of America

Eduardo Gentile Veiga