A fair and high speed arbitration system based on rotative and weighted priority monitoring

摘要

A mixed rotative and weighted arbiter for arbitrating the priority of request signals R1-Rn supplied from a plurality of devices is disclosed. The arbiter is composed of a token circuit which delivers a token vector having one position set active.The token vector as well as the plurality of request signals are input to a rotative arbitration circuit. The rotative arbitration circuit processes a round robin algorithm to output a rotative request vector having input requests ordered from a higher to a lower priority configuration according to the active position of the token vector. The arbiter further comprises a weighted arbitration circuit connected to the output of the rotative arbitration circuit for generating a weighted request vector determining a linear priority configuration of the rotative request vector. A grant generation circuit is connected to the output of the weighted arbitration circuit and to the output of the token circuit to deliver a grant order to the device which may gain access to the bus and a plurality of no grant orders to the others devices. <IMAGE>