PREFETCH STREAM FILTER WITH FIFO ALLOCATION AND STREAM DIRECTION PREDICTION

摘要

A prefetch filter receives a memory read request having an associated address for accessing data that is stored in a line of memory. An address window is determined that has an address range that encompasses an address space that is twice as large as the line of memory. In response to a determination of in which half the address window includes the requested line of memory, a prefetch direction is to a first direction or to an opposite direction. The prefetch filter can include an array of slots for storing a portion of a next predicted access and determine a memory stream in response to a hit on the array by a subsequent memory request. The prefetch filter FIFO counter cycles through the slots of the array before wrapping around to a first slot of the array for storing a next predicted address portion.