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. 16, 1993
Filed:
Jun. 29, 1990
John H Zurawski, Boxboro, MA (US);
Raj Ramanujan, Leominster, MA (US);
John De Rosa, Princeton, MA (US);
Digital Equipment Corporation, Maynard, MA (US);
Abstract
A cache coherency scheme in a multiprocessor computer system allows data sharing between caches at a fast rate. A new cache coherency state is introduced which allows a processor pair to more effectively share data and eliminate bus transfers thereby improving system throughput. The transfer of data is accomplished by the returning a portion of a preselected data block pursuant to either a read or a read for ownership request by a first one of the processors of the processor pair by the second processor of the processor pair. The ownership of the portion of the preselected data block is shared by the processor pair. Both processors set an indicator to denote that the preselected data block is an incomplete data block.