| 摘要 |
Apparatus and method for improving index reference position detection on a disc of a disc drive. The disc includes servo fields used by a servo circuit to control position of a head adjacent the disc and data fields used to store user data, with at least one data field between each successive pair of servo fields. Each servo field includes a binary index field used to indicate angular position. A multi-bit index detection word is selected having at least two bits at a first logical state and at least two bits at a second logical state. A plurality of index fields leading up to, and including a selected index field at the index reference position, are written with respective patterns corresponding to the logical sequence of the index detection word. As the disc rotates, the servo circuit reads each of the successive index fields and identifies the index reference position upon detection of the index detection word.
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