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.

Date of Patent:
Jun. 15, 1993

Filed:

Apr. 13, 1992
Applicant:
Inventors:

Neal Glover, Bloomfield, CO (US);

Peter Murray, Louisville, CO (US);

Assignee:

Cirrus Logic, Inc., Fremont, CA (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03L / ;
U.S. Cl.
CPC ...
331 25 ; 331D / ;
Abstract

A Loss of Lock Detector and Re-lock Control function using digital techniques to detect a programmable difference in frequencies over a programmable range. Once Loss of Lock is detected, the Re-lock sequence is initiated and PLLIS, PLLMS & PLLGS are stepped through a programmable sequence. The invention detects the frequency difference by counting down two counters and evaluating the value left in one when the other reaches terminal count using a programmable tolerance of frequency differences before Loss of Lock is declared. The complexity and cost of implementation of the invention is reduced by multiple use of a single down counter. Other features of the invention are disclosed.


Find Patent Forward Citations

Loading…