ALLOTTING METHOD FOR SYSTEM RESOURCE IN HIERARCHICAL BUS STRUCTURE

PROBLEM TO BE SOLVED: To easily and speedily allot resources needed for multi-layered PCI bus architecture by grouping classified lists by first-fit algorithm and determining resource allotment to respective buses in bus layers. SOLUTION: A host processor 12 executes proper commands to determine a request to allot resources to respective devices. After this request is determined, requests of respective PCI (peripheral component interconnect) buses 19, 23, 25, 29, 36, and 39 in layers are determined. Then the buses 29 and 39 of the lowest order in the layers are discriminated and then resource allotment request of the device connected to the specific bus 29 or 39 of the lowest order is grouped into the request of the whole buses. This grouping acquires the resource request of the whole buses by using the first-fit algorithm. Consequently, the resources needed for the multi-layered PCI bus architecture can easily and speedily be allotted.