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:
Apr. 11, 2000
Filed:
Jul. 08, 1998
Kenichi Ishibashi, Kokubunji, JP;
Takehisa Hayashi, Sagamihara, JP;
Tsutomu Goto, Yokohama, JP;
Hideki Murayama, Kunitachi, JP;
Akira Yamagiwa, Kanagawa-ken, JP;
Yasuhiro Ishii, Hadano, JP;
Naoki Hamanaka, Tokyo, JP;
Masabumi Shibata, Kawasaki, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A semiconductor integrated circuit system having a function of automatically adjusting an output resistance value with reference to a temperature of an LSI which is operating. When a count value obtained from a counter by counting the output of a timer becomes equal to a predetermined value, a temperature sensor measures temperatures of LSIs. If a temperature fluctuation measured from a previous measured value is greater than a predetermined width, then a control apparatus issues an output resistance value adjustment request signal to output resistance adjustment units of the LSIs. When receiving the output resistance value adjustment request signal, the output resistance value adjustment units stop the signal transmission between the LSIs, adjust output resistance values of output circuits in such a manner that the output resistance values are matched with a characteristic impedance of a transmission line, and maintains the adjusted output resistance values until the output resistance value adjustment units receive next output resistance value adjustment request signal.