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:
Mar. 22, 2011
Filed:
Oct. 27, 2009
Applicant:
Masafumi Kondou, Kawasaki, JP;
Inventor:
Masafumi Kondou, Kawasaki, JP;
Assignee:
Fujitsu Limited, Kawasaki, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03K 3/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
A clock signal generation apparatus includes a clock signal generation circuit generating a plurality of clock signals, and a self-test circuit measuring a phase difference of one pair of clock signals. The self-test circuit includes a clock signal selection circuit selecting the pair of clock signals among the plurality of clock signals, a phase detection circuit generating a phase difference pulse signal, a test signal generation circuit generating a test signal having a frequency which is lower than the phase difference pulse signal, and a counter circuit counting the pulse number of the test signal.