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. 05, 2009
Filed:
Jun. 05, 2002
Manuel Joseph Alvarez, Ii, Austin, TX (US);
Sanjay Raghunath Deshpande, Austin, TX (US);
Kenneth Douglas Klapproth, Austin, TX (US);
David Mui, Round Rock, TX (US);
Manuel Joseph Alvarez, II, Austin, TX (US);
Sanjay Raghunath Deshpande, Austin, TX (US);
Kenneth Douglas Klapproth, Austin, TX (US);
David Mui, Round Rock, TX (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A distributed system structure for a large-way, symmetric multiprocessor system using a bus-based cache-coherence protocol is provided. The distributed system structure contains an address switch, multiple memory subsystems, and multiple master devices, either processors, I/O agents, or coherent memory adapters, organized into a set of nodes supported by a node controller. The node controller receives transactions from a master device, communicates with a master device as another master device or as a slave device, and queues transactions received from a master device. Since the achievement of coherency is distributed in time and space, the node controller helps to maintain cache coherency. A transaction tag format for a standard bus protocol is expanded to ensure unique transaction tags are maintained throughout the system. A sideband signal is used for intervention and Reruns to preserve transaction tags at the node controller in certain circumstances.