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:
May. 11, 1993
Filed:
Jul. 09, 1992
Lishing Liu, Pleasantville, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A tightly coupled multi-processor (MP) system is provided with large granularity locking of exclusivity in multi-processor caches. The unique access right for a processor P.sub.i is enforced by giving other central processors (CPs) a temporarily invalid (TI) state on block B, even though some lines in the block B may still be resident in the cache. Any CP trying to access a block in the TI state will need to talk to the storage control element (SCE) to obtain proper authorization (e.g., RO or EX state) on the block. Assuming that a CP may have three states on a block B, temporarily invalid TI.sub.B, read only RO.sub.B and exclusive EX.sub.B, TI.sub.B is the initial state for all B at all CPs.