Western Digital Technologies, Inc.

Davide Giovenzana

Teik Ee Yeo

Paul E Soderbloom

Guoxiao Guo

Jie Yu

John W Vanlaanen

Michael Sheperek

Richard Koonwai Wong

Galvin Chia

Prakash Balasubramaniam

Philip S Gordon

Honge Wang

Some embodiments described herein are directed to reducing or eliminating latency caused by data zone switches in a rotating magnetic storage device. More specifically, some embodiments described herein are directed to storing parameters associated with different zones in a parameter register in response to one or more received commands.

Allowing fast data zone switches on data storage devices

A disk drive is disclosed comprising a disk comprising a track, wherein the track comprises a sync mark. The disk drive further comprises a head comprising a plurality of read sensors including a first read sensor, and a second read sensor separated from the first read sensor by a down-track spacing. A first time-stamp (TS) is generated after detecting the sync mark using the first read sensor as the disk rotates, and a second time-stamp (TS) is generated after detecting the sync mark using the second read sensor as the disk rotates. A calibration value representing the down-track spacing is generated based on the TSand the TS

Disk drive measuring down-track spacing of read sensors

A data storage device is disclosed comprising a disk comprising a plurality of tracks, where each track comprises a plurality of servo sectors and at least one data segment between consecutive servo sectors. The data storage device further comprises a head actuated over the disk, the head comprising a laser configured to heat the disk during write operations based on a laser power. During a first revolution of the disk, the laser power is first increased over a first interval to cause at least part of the head to protrude toward a first data segment of the disk. After the first interval, the laser power is decreased and a fly height pattern is read from the first data segment to first measure a fly height of the head.

Data storage device measuring laser protrusion fly height profile

A disk drive is disclosed comprising a disk having a plurality of data tracks defined by servo sectors, where each data track comprises a plurality of data sectors, and each servo sector comprises a servo preamble and servo data. The disk drive further comprises a head comprising a read element and a write element, and a servo read channel comprising an analog front end and a timing recovery circuit. During an access operation, data preceding the servo preamble of a first servo sector in the first data track is read in order to initialize the analog front end of the servo read channel. At least part of the servo preamble is read to initialize the timing recovery circuit of the servo read channel, and at least part of the servo data of the servo sector is read using the timing recovery circuit.

Disk drive initializing servo read channel by reading data preceding servo preamble during access operation

A disk drive is disclosed comprising a disk comprising a plurality of servo tracks defined by servo sectors. The disk drive further comprises a head comprising a read element offset linearly from a write element by a gap such that when the disk rotates, the read element reaches a servo sector before the write element. During a first operation, a first length of a beginning of the servo sector is read, and during a write operation, a second length of the beginning of the servo sector shorter than the first length is read to enable data to be written while the read element is over at least part of the servo sector.

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Longmont, CO, United States of America

Davide Giovenzana