METHOD FOR REPLACING CACHE MEMORY BLOCKS WITH FOR LOWER AMOUNT OF WRITE TRAFFIC AND INFORMATION PROCESSING APPARATUS HAVING CACHE SUBSYSTEM USING THE SAME

摘要

The cache subsystem of the present invention includes a cache data store for storing data blocks fetched from a lower cache or main memory into each of the cache blocks belonging to at least one mapping set and each including a plurality of lines, A sub information storage unit for storing additional information including a tag, a reference field, a valid bit, and a plurality of update bits allocated for each line, and an upper cache or processor communicating line by line and a lower cache or main memory And when a predetermined cache block replacement event occurs, the number of the reference fields and the number of update bits in the additional information stored in the additional information storage unit with respect to each cache block belonging to a certain mapping set that requires cache block replacement On the basis of this, among the cache blocks in the cache data storage unit, Selected, and can comprise a cache control section for replacing the selected replacement destination cache block.