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:
May. 24, 2005
Filed:
Aug. 18, 2003
Westerfield J. Ficken, Cary, NC (US);
Louis L. Hsu, Fishkill, NY (US);
James S. Mason, Hampshire, GB;
Phil J. Murfet, Hampshire, GB;
Westerfield J. Ficken, Cary, NC (US);
Louis L. Hsu, Fishkill, NY (US);
James S. Mason, Hampshire, GB;
Phil J. Murfet, Hampshire, GB;
International Business Machines Corporation, Armonk, NY (US);
Abstract
An apparatus and method is provided for detecting loss of differential signal carried by a pair of differential signal lines. According to the method, a common mode level is detected from voltages on the pair of differential signal lines. A threshold level is generated, referenced to the detected common mode level. A signal level is generated from the voltages on the pair of differential signal lines, the signal level being averaged over a first period of time. From the threshold level and the detected common mode level a reference level is generated, the reference level being averaged over a second period of time longer than then the first period of time. The signal level is compared to the reference level to determine if a signal is present on the pair of differential signal lines.