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:
Sep. 28, 1993
Filed:
Dec. 24, 1990
Vernon K Boland, Durham, NC (US);
NCR Corporation, Dayton, OH (US);
Abstract
A method and apparatus for providing coherency for cache data in a multiple processor system with the processors distributed among multiple independent data paths. The apparatus includes a set of cache monitors, sometimes called snoopers, associated with each cache memory. There are the same number of monitors as there are independent data paths. Thus, each cache stores cache tags that correspond to its currently encached data into each of the monitors of the set associated therewith. Thus, each cache has an monitor associated therewith which monitors each of the multiple paths for an operation at an address that corresponds to data stored in its cache. If such an access is detected by one of the set of monitors, the monitor notifies its cache so that appropriate action will be taken to ensure cache data coherency.