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:
Jul. 29, 2003
Filed:
Apr. 15, 1999
Tetsuya Shimomura, Hitachi, JP;
Shigeru Matsuo, Hitachinaka, JP;
Kazuyoshi Koga, Kodaira, JP;
Koyo Katsura, Hitachiohta, JP;
Yasuhiro Nakatsuka, Tokai-mura, JP;
Kazushige Yamagishi, Higashimurayama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In order to assure that a plurality of circuits such as a CPU I/F circuit, a rendering circuit, a video input circuit and a display circuit, which are each required to always complete a processing within a prescribed time, are each assured the ability to make as many accesses to a memory as required to complete the processing within the prescribed time, it is necessary to arbitrate a contention for an access to the memory through an internal bus among the circuits by employing a bus control circuit wherein priority levels assigned to the circuits to make an access to the internal bus are dynamically changed by comparing degrees of access urgency among the circuits. In this way, circuits that each have to always complete theirs processing within a prescribed time are assured the ability to make as many accesses to the memory as required to complete the processing within the prescribed time even if a plurality of such circuits do exist.