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. 06, 1983
Filed:
Jan. 29, 1982
John E Bjornholt, Mesa, AZ (US);
Motorola Inc., Schaumburg, IL (US);
Abstract
An augmented phase-locked loop for use with a data communication system in which the data is encoded into a plurality of symbol signals such that the channel on which transmission occurs is switched at a data clock rate between symbol signals and such that two like symbol signals cannot appear successively. The coincidental transitions between symbol signals are detected and are used to lock a phase-locked loop. If the integrated signal from a transition detector is greater than integration of the signal level of the pluses on each incoming channel at the frequency of the loop locking to a subharmonic is detected and causes a sweep circuit to drive an oscillator to sweep until the phase-locked loop locks on the correct data clock frequency. The frequency to which the loop is locked is used to clock a successive sampling of each input so that if the loop is locked on a harmonic of the correct data clock, the sequential repetition of a symbol signal on a channel is detected and is used to force an oscillator to sweep until the phase-locked loop is locked to the correct data clock frequency.