Patent ID: 8605379

Claim:
A disk drive comprising: a disk comprising a plurality of servo tracks, wherein each servo track comprises a plurality of servo sectors; a head actuated radially over the disk, wherein the head comprises a read element separated from a write element by a reader/writer gap; and control circuitry operable to: position the head over a first servo track; synchronize a first clock to servo data in first and second servo sectors of the first servo track, wherein a length of the reader/writer gap comprises a non-integer number of cycles of the first clock at the first servo track; measure a first phase-offset of the first clock for the first servo sector and measure a second phase-offset of the first clock for the second servo sector, wherein the first and second phase-offset correspond to an end of the reader/writer gap at the first servo track; and average the first and second phase-offset to generate a first average phase-offset for the first servo track.