Patent ID: 7363432

Claim:
A system, comprising: a memory comprising: a plurality of data items and a plurality of directory information items, each data item uniquely associated with one of the plurality of directory information items; wherein each of the plurality of data items is configured in accordance with one of a plurality of access modes; wherein each of the plurality of directory information items comprises indicia of the access mode of its associated data item; a multiplexer coupled to the memory and comprising a multiplex ratio; a plurality of buffers coupled to the multiplexer and to the memory; wherein the multiplex ratio is a function of the number of buffers in the plurality of buffers; and a plurality of multiplexer/demultiplexers (MDMs), each MDM uniquely coupled to a different one of the plurality of buffers; a plurality of processing elements coupled to the memory, wherein each of the processing elements uniquely couples in a point-to-point connection to a different one of the plurality of MDMs; wherein each of the processing elements is configured to transmit a data request to its associated MDM, the data request identifying one of the plurality of data items and an access mode; wherein the memory is configured to transmit a data response to each of the processing elements in response to a data request, the data response comprising the identified data item and its associated directory information; and wherein each of the processing elements is further configured: to receive the data response and to compare the associated directory information with the access mode of the data request; and in the event that the associated directory information and the access mode of the data request are not compatible, to initiate coherence actions for the requested data item.