Patent ID: 6989954

Claim:
A method of manufacturing a disk drive, the disk drive comprising control circuitry and a head disk assembly (HDA) comprising a disk, an actuator arm, a head connected to a distal end of the actuator arm, and a voice coil motor for rotating the actuator arm about a pivot to position the head radially over the disk, the disk comprising a plurality of spiral tracks, each spiral track comprising a high frequency signal interrupted at a predetermined interval by a sync mark, the method comprising the steps of: (a) writing product servo sectors to the disk to define a plurality of radially spaced, concentric data tracks by: using the head internal to the disk drive to read the spiral tracks to generate a read signal; using burst demodulation circuitry to demodulate the read signal representing the high frequency signal between the sync marks in one of the spiral tracks into a plurality of respective servo burst signals; processing the servo burst signals generated from reading the spiral track to generate a position error signal used to maintain the head along a substantially circular target path; using the head internal to the disk drive to write product servo sectors along the circular target path, wherein each product servo sector comprises a plurality of servo bursts; (b) using the head internal to the disk drive to read the product servo sectors to generate the read signal; (c) using the burst demodulation circuitry to demodulate the read signal representing the servo bursts in one of the product servo sectors into a plurality of respective servo burst signals; and (g) processing the servo burst signals generated from reading the product servo sector to generate a position error signal used to maintain the head along a substantially circular target path.