Method and system for supporting multiple local buses operating at different frequencies

摘要

A method and system for supporting multiple Peripheral Component Interconnect (PCI) local buses through a single PCI host bridge having multiple PCI interfaces within a data-processing system are disclosed. In accordance with the method and system of the present invention, a processor and a system memory are connected to a system bus. One or more PCI local buses are connected to the system bus through a single PCI host bridge having bus and frequency control logic and bus clocks. The PCI local buses include sets of in-line electronic switches, dividing each PCI local bus into PCI local bus segments for supporting more PCI peripheral component slots then are called out by the PCI local bus standard. The sets of in-line electronic switches are open and closed in accordance with the bus and frequency control logic within the PCI host bridge thereby allowing the PCI peripheral component slots to operate at different bus frequencies, including bus frequencies higher than 66 MHz by using the bus clocks. The sets of in-line electronic switches further allowing different bus segments on the same PCI logical bus to dynamically be operated at different frequencies.