ROUND-ROBIN SHARED BUS ARBITRATION PROVIDING PREFERENCE TO LOWER PRIORITY UNITS AFTER BUS ACCESS BY A HIGHER PRIORITY

A protocol is disclosed for the round-robin distributed arbitration of access to a common resource, such as a bus, in a multiprocessor system or machine. The protocol assigns identity values to each agent, or processor, which are compared during each arbitration to determine which agent is awarded control of the bus. To enhance fairness agents having an identity value lower than the winner of the last arbitration are favored over agents having a higher identity value in the next subsequent arbitration.