ADAPTIVE BUS ARBITRATION SYSTEM

PURPOSE:To effectively distribute the bus resources by deciding the priority of the bus using right based on the total bus using frequency of each device within a fixed time. CONSTITUTION:The devices 1 - N are provided with the arbiters 1a - Na which perform the bus arbitration, the transfer counters 1t - Nt which totalize the number of transfer data, the device numbers 1n - Nn respectively. Each device totalizes the hitherto bus using frequencies within a fixed time, and the priority of each device is decided for arbitration based on the totalized value of bus using frequency. For instance, the higher priorities are given to the devices in the order of lower total bus using frequencies measured in a fixed time. Then the arbitration control is carried out so that the bus using frequency is equalized among devices. Thus the bus using frequency can be equalized among 2 devices when these devices have the data transfer requests at one time. Then the bus resources effectively are distributed to the devices.