| 摘要 |
<p>Servo circuitry (325) is disclosed that is configured to operate with a magnetic disk drive system. The servo circuitry is comprised of a first servo detector system (401), a second servo detector system (402), and a comparator (416). The first servo detector system and the second servo detector system each receive samples, taken from a read signal, that include servo data. The first servo detector system compares the samples to a plurality of servo codes to generate a first selected code. The second servo detector system compares a first shifted version of the samples to the plurality of servo codes to generate a second selected code. The comparator receives the selected codes and selects one of the selected codes. The selected code represents the servo data (359). The servo circuitry could also include a third servo detector system (403) that operates on a second shifted version of the samples. Alternatively, the first servo detector system, the second servo detector system, and the third servo detector system could each be programmed with different servo codes. The first servo detector system compares the samples to a plurality of first servo codes. The second servo detector system compares the samples to a plurality of second servo codes. The third servo detector system compares the samples to a plurality of third servo codes. The second servo codes and the third servo codes are shifted versions of the first servo codes. In either embodiment, the servo circuitry advantageously has improved phase shift tolerance.</p> |
