| US 7,466,766 B2 | ||
| Processing servo data having DC level shifts | ||
| Pervez M. Aziz, Garland, Tex. (US) | ||
| Assigned to Agere Systems Inc., Allentown, Pa. (US) | ||
| Filed on Mar. 27, 2007, as Appl. No. 11/728,862. | ||
| Application 11/728862 is a continuation of application No. 10/436527, filed on May 13, 2003, granted, now 7,231,001. | ||
| Claims priority of provisional application 60/457041, filed on Mar. 24, 2003. | ||
| Prior Publication US 2007/0172005 A1, Jul. 26, 2007 | ||
| Int. Cl. H04L 25/06 (2006.01) | ||
| U.S. Cl. 375—319 | 24 Claims |
| 1. An apparatus for detecting data in a signal read from a channel, the apparatus comprising:
an equalizer configured to apply equalization to the signal to account for a DC shift in the signal; and
a detector adapted to detect the data based on either the presence or absence of the DC shift in the signal; and further comprising:
a DC shift detector adapted to detect the presence or absence of the DC shift in the signal and to generate a corresponding
DC shift detect signal;
wherein the equalizer, in response to the DC shift detect signal, modifies the equalization to Nyquist equalization when the
DC shift detect signal indicates the presence of the DC shift in the signal.
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