Patent ID: 6973545
Filing Date: 2005-12-06
Classification: G06F

Abstract:
1. A computer system comprising: a plurality of active devices, wherein the plurality of active devices includes a first active device, wherein the first active device includes a first cache configured to store data accessed by the first active device; a directory configured to indicate which of the plurality of active devices has an ownership responsibility for a given coherency unit; an address network for conveying address packets point-to-point between the plurality of active devices and the directory; a data network for conveying data packets between the plurality of active devices; wherein the first active device is configured to transition an ownership responsibility for a first coherency unit cached in the first cache upon receipt of a first address packet and to transition an access right to the first coherency unit cached in the first cache upon receipt of a corresponding data packet, wherein the ownership responsibility transitions at a different time than the access right transitions.