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:
Dec. 17, 2013
Filed:
Sep. 14, 2012
Lip Kai Soh, Sitiawan Perak, MY;
Lip Kai Soh, Sitiawan Perak, MY;
Altera Corporation, San Jose, CA (US);
Abstract
One embodiment relates to a lock detection circuit. The lock detection circuit includes at least a dither detection circuit and a lock filter. The dither detection circuit maintains a bi-directional count based on early and late signals from a sampler circuit and asserts a non-lock signal if the bi-directional count reaches either a positive non-lock assertion threshold or a negative non-lock assertion threshold. The lock filter increments a lock filter count for each sample and outputs a lock-initiated signal when the lock filter count reaches a pre-set maximum value. The maximum value of the lock filter count is greater than the non-lock assertion thresholds. Other embodiments and features are also disclosed.