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:
Aug. 21, 2001
Filed:
May. 08, 2000
Mitsuo Baba, Tokyo, JP;
Yasushi Aoki, Tokyo, JP;
Minoru Kayano, Tokyo, JP;
Yuuji Takahashi, Tokyo, JP;
Atsushi Katayama, Tokyo, JP;
NEC Corporation, Tokyo, JP;
Abstract
A bit synchronization circuit extracts the central phase of an eye opening irrespective of a jitter distribution of input data to maintain an optimum timing adjustment margin. The bit synchronization circuit has a data edge detector for comparing the phases of an edge of the input data and m-phase clock signals divided from a reference clock. Data edge phase information from the data edge detector is accumulated by a phase accumulation register, which stores the jitter distribution of the input data as accumulated phase information. Based on the accumulated phase information, an eye center phase calculator decodes the negative and positive ends of a jitter range as negative jitter range information and positive jitter range information, and calculates a phase control direction in relation to an extracted phase value which represents a presently selected clock phase. A correction circuit extracts the positional relationship between a present eye opening width and the extracted phase value, and clears the accumulated phase information to increase the eye opening width.