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:
Nov. 03, 2009
Filed:
Aug. 31, 2006
Applicants:
Keitaro Uehara, Kokubunji, JP;
Jun Okitsu, Kokubunji, JP;
Yoshiki Murakami, Hadano, JP;
Inventors:
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06F 12/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
In a multi-processor system, counting snoop results bottlenecks the broadcast-based snoop protocol. The directory-based protocol delays the latency when remote node caches data. There is a need for shortening the memory access latency using a snoop and cache copy tag information. When the local node's cache copy tag information is available, the memory access latency can be shortened by omitting a process to count snoop results. When memory position information is used to update the cache copy tag during cache replacement, it is possible to increase a ratio to hit a copy tag during reaccess from the local node.