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:
Jun. 24, 2008
Filed:
Aug. 14, 2006
Shosaku Yamasaki, Kawasaki, JP;
Shosaku Yamasaki, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A clock anomaly detection circuit includes: a dividing unit configured to output a divided target clock by dividing frequency of a target clock; a first time width measurement unit configured to obtain values of the divided target clock using rising edges of a monitoring clock that is synchronized with the target clock, and to measure an H level time with and an L level time width; a second time width measurement unit configured to obtain values of the divided target clock using falling edges of the monitoring clock, and to measure an H level time with and an L level time width; and an anomaly determination unit configured to determine that the target clock is abnormal when an anomaly is detected in the H level time width or the L level time width measured in the first time width measurement unit and when an anomaly is detected in the H level time width or the L level time width measured in the second time width measurement unit.