Patent ID: 6792498
Filing Date: 2004-09-14
Classification: G06F

Abstract:
A memory system comprising:a first cache memory of a high rank close to a processor; a second cache memory or a main memory device of a lower rank; a first table for registering a least one line address of a previous transfer request for line data, the previous transfer request for said line data being made to said second cache memory or said main memory device when the line data is not available in said first cache memory; first means for comparing the line address registered in said first table with a line address of a new transfer request for line data, the new transfer request for said line data being made to said second cache memory or said main memory device when the line data is not available in said first cache memory; a first buffer for storing thrashing line data, which is transferred from said second cache memory or said main memory device due to thrashing, in a part of said second line memory or main memory device; a second table for registering at least one corresponding trashing line address to the thrashing line data to be stored in said first buffer; second means for comparing said line address of said new transfer request for line data with said thrashing line address in said second table at a time of making the transfer request for the thrashing line data; means for registering said line address of said new transfer request in said second table with respect to said flagged line data transfer request; means for storing line data in said first buffer when said thrashing line address has been registered in said second table during transferring the thrashing line data from said main memory device or said second cache memory; and means for transferring the thrashing line data to a transfer requester from said first buffer when a result generated by the second means for comparing is a hit, Wherein a result generated by the first means for comparing is either a hit or a mishit, and when the result is a miss-hit, said line address of said new transfer request is registered in said first table, and a flagged line data transfer request having a flag indicating the result being a hit is generated.