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. 20, 2002
Filed:
Jun. 14, 1999
Hideya Akashi, Kunitachi, JP;
Toshio Okochi, Dublin, IE;
Toru Shonai, Kodaira, JP;
Masamori Kashiyama, Isehara, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A multi-processor system includes a plurality of processor node control circuits in respective processor nodes, and a cache memory which is an external cache. Each of the processor node control circuits includes a summarized cache tag memory for storing “summarized information” which is information having a reduced number of bits by summarizing information on a cache tag portion in the cache memory and indicating whether each of blocks is effectively indexed in the cache tag portion. For cache coherence control, the summarized cache tag memory is first accessed, so that the cache tag portion is accessed only when it is determined that a target block is effectively indexed, to determine whether the cache coherence control for the node is required.