Detection of speculative precharge

Abstract

A DRAM controller may be configured to re-order read/write requests to maximize the number of page hits and minimize the number of page conflicts and page misses. A three-level prediction algorithm may be performed to obtain auto-precharge prediction for each read/write request, without having to track every individual page. Instead, the DRAM controller may track the history of page activity for each bank of DRAM, and make a prediction to first order based history that is not bank based. The memory requests may be stored in a queue, a specified number at a time, and used to determine whether a page should be closed or left open following access to that page. If no future requests in the queue are to the given bank containing the page, recent bank history for that bank may be used to obtain a prediction whether the page should be closed or left open. If the page is not closed as a result of the determination and/or prediction, it may be left open and closed after it has remained idle a specified length of time following the last access to the page.