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:
Oct. 08, 2002
Filed:
Dec. 29, 2000
Phillip M. Jones, Spring, TX (US);
Robert L. Woods, Allentown, PA (US);
Compaq Information Technologies Group, L.P., Houston, TX (US);
Abstract
An apparatus for identifying memory requests originating on remote I/O devices as non-cacheable in a computer system with multiple processors includes a main memory, memory cache, processor, cache coherence directory and cache coherence controller all coupled to a host bridge unit (North bridge). The I/O device transmits requests for data to an I/O bridge unit. The I/O bridge unit forwards the request for data to the host bridge unit and asserts a sideband signal to the host bridge unit if the request is for non-cacheable data. The sideband signal informs the host bridge unit that the memory request is for non-cacheable data and that the cache coherence controller does not need to perform a cache coherence directory lookup. For cacheable data, the cache coherence controller performs a cache coherence directory lookup to maintain the coherence of data stored in a plurality of processor caches in the computer system.