Patent ID: 7961416

Claim:
A hard-disk drive comprising: an enclosure; a magnetic read/write head; a magnetic-recording disk rotatably mounted on a spindle; a drive motor mounted in said enclosure, said drive motor having a motor shaft attached to said spindle for rotating said magnetic-recording disk; a voice-coil motor configured to move said magnetic read/write head to access portions of said magnetic-recording disk; and one or more electronic components for reading servo data stored on the magnetic-recording disk, wherein the one or more electronic components are configured to perform: collecting statistics that describe the proportion of high frequency values to low frequency values in a readback signal, wherein the readback signal is read by the magnetic read/write head from a portion of the magnetic-recording disk, determining an estimated location of the magnetic read/write head using the statistics, determining, based on the estimated location of the magnetic read/write head, an estimated clock frequency for the readback channel to use in reading the servo data stored on the magnetic-recording disk, and the readback channel reading the servo data, from the magnetic-recording disk, using the estimated clock frequency.