I/O CONTROLLER WITH A DYNAMICALLY ADJUSTABLE CACHE MEMORY

摘要

A controller I/O (20) for transferring data between a host processor (10) and a plurality of attachment devices (16) comprises a cache memory (42) provided for storing blocks of data which are most likely to be needed in the near future. When transferring data to cache memory (42) from an attachment device (16), additional unrequested information can be transferred at the same time if it is likely that this additional data will soon be requested. Further memory (47) includes a directory table wherein all data in cache memory (42) is listed at a <> position and, if more than one block of data in cache memory (42) have the same home position, a conflict chain is set-up so that checking the contents of the cache memory (42) can be done simply and quickly.