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:
Dec. 26, 1989
Filed:
Feb. 12, 1988
Applicant:
Inventor:
Paul A Devries, Wayne, MI (US);
Assignee:
Northern Telecom Limited, Montreal, CA;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03D / ;
U.S. Cl.
CPC ...
375120 ; 331 / ; 375 82 ;
Abstract
A dual-tracking phase-locked loop circuit is provided for moving with minimum disruption from conventional PLL operation to processor-controlled tracking of another closely related clock. In addition to conventional PLL components the circuit comprises a processor-controlled up/down counter which may operate alternatively as a link in the loop or as providing the base-line frequency determining value at the time of transition from PLL to processor-controlled tracking operation, thereby ensuring none disruptive transition.