Patent ID: 7405897
Filing Date: 2008-07-29
Classification: G11B

Abstract:
1. A method for writing embedded servo position information in the data storage tracks of a data storage device (DSD) having (1) a rotating data storage medium with at least one data storage surface containing the data storage tracks each disposed over a plurality of sectors, (2) a read/write head (RWH) disposed in a transducing relationship with the data storage surface, (3) an actuator for disposing the RWH in a radial position on the data storage surface according to a voice-coil motor (VCM) signal value, (4) at least one crashstop disposed to limit actuator motion, and (5) a servo control loop for producing the VCM signal responsive to information read from the data storage surface, the method comprising the steps of: (a) forcing the actuator against a crashstop, thereby moving the RWH to a crashstop region of the data storage surface; (b) writing an open-loop sequence of servo bursts in the crashstop region; (c) writing a closed-loop sequence of servo bursts each positioned in the crashstop region according to amplitude information read from a plurality of servo bursts written earlier; (d) writing a plurality of closed-loop servo seed tracks each positioned in the crashstop region according to amplitude information read from a plurality of servo bursts written earlier; and (e) writing a plurality of servo tracks each positioned according to servo positioning information read from a servo track written earlier, whereby the servo tracks are propagated across the data storage surface from the servo seed tracks under servo loop control.