Patent ID: 9013819
Filing Date: 2015-04-21
Classification: G11B

Abstract:
1. An apparatus comprising: circuitry configured to produce a servo detect pulse based on a waveform, wherein the waveform is produced by a read head operated with respect to a recording medium, the medium comprising magnetic data positions, servo sync marks, and phase tracking fields arranged between a first servo sync mark of the servo sync marks and a second servo sync mark of the servo sync marks, wherein the servo detect pulse indicates a detection of at least one of the servo sync marks; circuitry configured to produce, responsive to the servo detect pulse, calibration pulses, wherein each of the calibration pulses corresponds to a passage of the read head over one of the phase tracking fields; and circuitry configured to control, responsive to the calibration pulses, adjustments of a phase of a write clock signal to align the write clock signal with at least a portion of the data positions, wherein the adjustments are based on groups of samples of the waveform that respectively correspond to the phase tracking fields.