System bus read data transfers with bus utilization based data ordering

Abstract

A method for selecting an order of data transmittal based on system bus utilization of a data processing system. The method comprises the steps of coupling system components to a processor within the data processing system to effectuate data transfer, dynamically determining based on current system bus loading, an order in which to retrieve and transmit data from the system component to the processor, and informing the processor of the order selected by issuing to the data bus a plurality of selected order bits concurrent with the transmittal of the data, wherein the selected order bit alerts the processor of the order and the data is transmitted in that order. In a preferred embodiment, the system component is a cache and a system monitor monitors the system bus usage/loading. When a read request appears at the cache, the modified cache controller preference order logic or a preference order logic component determines the order to transmit the data wherein the order is selected to substantially optimize data bandwidth when the system bus usage is high and selected to substantially optimize data latency when system bus usage is low.