Intel Corporation
System and method for replacement in associative memories using weighted PLRU trees

Abstract:

A processor includes an associative memory including ways organized in an asymmetric tree structure, a replacement control unit including a decision node indicator whose value determines the side of the tree structure to which a next memory element replacement operation is directed, and circuitry to cause, responsive to a miss in the associative memory while the decision node indicator points to the minority side of the tree structure, the decision node indicator to point a majority side of the tree structure, and to determine, responsive to a miss while the decision node indicator points to the majority side of the tree structure, whether or not to cause the decision node indicator to point to the minority side of the tree structure, the determination being dependent on a current replacement weight value. The replacement weight value may be counter-based or a probabilistic weight value.