Western Digital Technologies, Inc.

Western Digital Corporation

Ralph A Proud

Raffi Codilian

Marc B Goldstone

Kenneth D Donner

Reduced bit number wedge identification techniques for use within a rotating media storage device (RMSD) are disclosed. The RMSD includes a disk having a circumferential track that includes a plurality of embedded servo wedges utilized in track following. A substantial majority of the plurality of wedges include a reduced bit wedge ID field that does not have a sufficient number of bits to uniquely identify the wedge within the track. A combined wedge ID code is formed from reading at least first and second reduced bit wedge ID numbers from first and second wedges, respectively, which is used to uniquely identifying a wedge.

Reduced bit number wedge identification techniques within a rotating media storage device

A disk drive circuit that includes a configuration resistor, a reference resistor, a capacitor and a processor. The processor is mounted on a first circuit assembly in the disk drive, such as the controller circuit board, and the configuration resistor is mounted on a second circuit assembly, such as the head-disk assembly (I-IDA). The resistance of the configuration resistor corresponds to the configuration of the second circuit assembly. The configuration may represent the number of heads or the type of preamplifier in the IDA. The processor calculates the resistance of the configuration resistor to determine the configuration of the second circuit assembly in the following manner. The processor charges the capacitor. The processor then allows the capacitor to discharge through a first circuit that includes both the configuration resistor and the reference resistor and measures the discharge time or time constant. The processor again charges the capacitor. The processor then allows the capacitor to discharge through a second circuit that includes the configuration resistor but not the reference and measures the time constant. The processor calculates the resistance of the configuration resistor in response to the ratio of the time constants of the first and second circuits.

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Mission Viejo, CA, United States of America

Ralph A Proud