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. 06, 1987
Filed:
Feb. 24, 1986
Applicant:
Inventor:
Dale B Chapman, San Jose, CA (US);
Assignee:
International Business Machines Corporation, Armonk, NY (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H03L / ;
U.S. Cl.
CPC ...
331 / ; 331 17 ;
Abstract
A clock phase discriminator measures phase difference between a pair of digital clock signals to produce phase error signals used to adjust the frequency of one clock so as to reduce the phase difference. The discriminator includes a latch circuit that responds to successive transitions of the clock signals by undertaking a multistate phase measurement transition path in which only one state variable changes at a time. The latch circuit reduces the exposure of the phase discriminator to race conditions while measuring the phase difference and producing the error signals.