Method and system for memory control and access in data processing systems

Abstract

It has been discovered that a method and system can be produced which will, among other things, provide data processing systems having memory controllers with the ability to look ahead and intelligently schedule accesses to system memory. A method and system which improve data processing system memory access. The method and system provide a first-stage origin-sensitive memory access request reordering device, and a second-stage destination-sensitive memory access request reordering device operably coupled to said first-stage origin-sensitive memory access request reordering device. The first-stage origin-sensitive memory access request reordering device receives memory access requests having associated origin information, and reorders the memory access requests based upon the associated origin information. The first-stage origin-sensitive memory access request reordering device delivers to the second-stage destination-sensitive memory access request reordering device one or more memory access requests which the first-stage origin-sensitive memory access request reordering device has deemed to be the requests which should be next executed. The second-stage destination-sensitive memory access request reordering device receives such one or more reordered memory access requests from the first stage and, in conjunction with the state of various system memory devices, again reorders the requests on the basis of the state of various system memory devices, prior to executing the one or more requests.