Method and system for optimizing data transfers between devices interconnected by buses operating at different clocking speeds

Abstract

Disclosed is a method and apparatus for optimizing communication between buses operating at different frequencies. A high speed bus provides communication between high speed devices as well as provides communication to a lower speed bus which provides communications between low speed devices and between low speed devices and high speed devices. During transaction reset a bridge device that controls communication between the high and low speed buses determines the ratio of the respective bus clocks. The bridge device sets a logic state machine based on this data and selects from the higher frequency clock selected cycles on which transfers to the lower speed bus take place. The unused cycles of the high speed clock may then be used on the high speed bus for additional transfers. The clock ratios may be determined on each transaction reset and new data on clock ratios stored in the bridge device for subsequent operation.