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. 27, 1991
Filed:
Aug. 18, 1989
Noboru Masuda, Kokubunji, JP;
Hiroyuki Itoh, Kodaira, JP;
Bunichi Fujita, Hadano, JP;
Seiichi Kawashima, Hadano, JP;
Shuichi Ishii, Sayama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
The present invention relates to a clock signal supplying device provided with an automatic phase regulating function for preventing errors in the phase regulation due to noise. In the device according to the present invention, there is disposed a reference signal serving as a phase reference, and transmission lines for clock signals and a transmission line for the reference signal are disposed from a clock signal supplying source to devices which are destinations of the distribution of clock signals. The transmission line for the reference signal is adjusted in advance so as to produce no skew. In the device, which is the destination of distribution of the clock signal, there is disposed a variable delay circuit for regulation of the phase of the clock signal and a phase comparing circuit for comparing the output of the variable delay circuit with the phase of the reference signal to output the result of the comparison. In the device according to the present invention, a noise filter is provided which detects phase regulation errors to effect correct phase regulation. Furthermore, the phase regulation is effected while avoiding a period of time wherein noise is apt to be produced.