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. 13, 2003
Filed:
Dec. 13, 2001
Jean-Claude Abbiate, La Gaude, FR;
Carl Cederbaum, Nice, FR;
International Business Machines Corporation, Armonk, NY (US);
Abstract
A method and circuit for comparing the frequencies of two clocks (clock and clock ), without taking into account their phase, is disclosed. Each clock is associated to a circular counter ( - and - ) which are initialized to different values, and the contents of the circular counters are compared. When the frequencies of the two clocks (clock and clock ) are equal, both counters ( - and - ) are incremented at a common frequency and thus, due to the initialization conditions, the contents of both counters can never be equal. Conversely, when the frequencies of the two clocks are different, the counters ( - and - ) are not increased at a common frequency and thus, after several clock pulses, the contents of the counters are equal, indicating different clock frequencies. In a preferred embodiment, the circular counters ( - and - ) are 2-bit circular counters.