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:
Jun. 21, 1977
Filed:
Jun. 29, 1976
James Monroe Clark, Cedar Grove, NJ (US);
International Telephone and Telegraph Corporation, Nutley, NJ (US);
Abstract
Two D-type flip flops have a clock and a 1/4-bit delayed clock coupled to the D inputs of respective ones of the two flip flops to provide a +/- phase error of a present sample of digital data coupled to the clock inputs of the two flip flops and a second signal indicating a large/small phase error of the present sample of the data. A third signal indicating a +/- phase error of a previous state of the data is provided and a fourth signal indicating a large/small error of the previous state of the data is provided. A read only memory is responsive to the first, second, third and fourth signals in accordance with a given set of rules to produce a phase error signal with a clockwise change of phase states of the data providing a negative frequency error signal and a counter-clockwise change of phase states of the data providing a positive frequency error signal.