Disk drive centering sync frames on sync marks of a spiral track

摘要

A disk drive is disclosed comprising a head actuated over a disk comprising a plurality of spiral tracks. A first sync frame is first opened in response to a first frame offset during a first revolution of the disk, wherein the first sync frame corresponds to the head approaching a first sync mark in a first spiral track crossing. A first sync frame position error signal (PES) is generated representing a difference between a target framing of the first sync frame around the first sync mark and a detected framing of the first sync frame around the first sync mark. The first frame offset is adjusted in response to the first sync frame PES, and during a second revolution of the disk the first sync frame is second opened in response to the adjusted first frame offset.