The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 30, 2010
Filed:
Sep. 28, 2006
Tom Gibbons, Macungie, PA (US);
Kenneth W. Paist, Spring City, PA (US);
Mark Trafford, Fleetwood, PA (US);
William B. Wilson, Macungie, PA (US);
Tom Gibbons, Macungie, PA (US);
Kenneth W. Paist, Spring City, PA (US);
Mark Trafford, Fleetwood, PA (US);
William B. Wilson, Macungie, PA (US);
Agere Systems Inc., Allentown, PA (US);
Abstract
Methods and apparatus are provided for clock skew calibration in a clock and data recovery system. One aspect of the invention compensates for skew among a plurality of clocks in a clock and data recovery system. The clocks are applied to a plurality of latches to sample an incoming signal. A reference signal, such as a Nyquist signal, is applied to a data input of each of the latches. Statistics of 'early' and 'late' corrections applied to at least one of the clocks by a bang-bang phase detector in the clock and data recovery system are evaluated and a delay of a clock buffer associated with the at least one clock is adjusted to obtain approximately a 50% early-to-late ratio for the at least one clock. The clock and data recovery system ensures that the early-to-late ratio for the sum of the plurality of clocks is approximately 50%.