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:
Oct. 22, 2002
Filed:
May. 16, 2001
Applicant:
Inventor:
Naoya Kimura, Chiba, JP;
Assignee:
Oki Electric Industry Co, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03K 5/19 ;
U.S. Cl.
CPC ...
H03K 5/19 ;
Abstract
A circuit for detecting abnormality of a subject clock signal, includes a frequency dividing circuit for frequency-dividing a monitoring clock signal to provide a frequency-divided monitoring clock signal; a shift register which stores the frequency-divided monitoring clock signal in synchronization with the subject clock signal; and a plurality of abnormality evaluation circuits. The abnormality evaluation circuits operate complementarily each other in accordance with an output signal of the shift register and detect abnormality of the subject clock signal for a period of time corresponding to the cycle of the monitoring clock signal.