METHOD AND SYSTEM FOR MAINTAINING STRONG ORDER IN COHERENT MEMORY SYSTEM

摘要

PROBLEM TO BE SOLVED: To maintain strong order in a multiprocessor computer system having a coherent memory. ;SOLUTION: A memory transaction(MT) is sent from processors more than one to a processor agent(PA) 118. The PA 118 sends the transaction through cross bar switches(CB) 114 (114A-114D) to a memory agent(MA) 124. The MA 124 performs memory coherency operation and returns the MT through the CB 114 to the PA 118. The CB 114 can change the order to send the MT to the PA 118. Therefore, the MA 124 sends a time stamp (TA) through a dedicated link to the PA 118 for each MT. An arbitrator (A) in the PA 118 receives these TA and MT, reorders the MT while using that TA and sends that MT to the processors in the order sending that MT. Further, the MA 124 sends a parity signal together with each TA. The type of MT to be received from the MA 124 is reported to the A based on the specified combination of parity signal and TA. Corresponding to the type of MT, this A can change the order for sending the MT to these processors.;COPYRIGHT: (C)1998,JPO