Distributed first-come first-served bus allocation apparatus

Claim 1

A first-come first-served resource allocation system in which a plurality of devices share a common resource, each device being adapted for requesting control of said resource and for relinquishing control of said resource, said system including means (110, 140, 141, 142) for establishing an ordinal ranking among successive ones of said devices requesting control of said resource and means (120) responsive to relinquishment of control of the resource by a device contiguous in said ordinal ranking with an individual one of said devices for transferring control of said resource to the individual one of said requesting devices, said rank establishing means (110, 140, 141, 142) characterized by, first means (111) for storing an indicium of an unassigned ordinal position, separate means (112) associated with respective ones of said devices responsive to a request for control of said resource by one of said devices for assigning to that same device the indicium of the unassigned ordinal position currently stored in said first storing means (111), and first means (113a, 113b, 114, 115) responsive to each request for control of said resource by any of said devices for changing the indicium of the assigned ordinal position in said first storing means (111) to the indicium of the next unassigned ordinal position, wherein the rank establishing means operates independent from and concurrent with the means for transferring control of the resource thereby allowing control to be transferred from one device relinquishing control of the resource to the requesting device with minimal delay.