device using the test bar award 'first come, first served' in systems sharing a resource

摘要

First-come, first-served bus allocation apparatus are distributed to each device sharing a common resource, such as a data bus. Bus allocation is achieved by placing each request from a device for control of the resource in an ordinal ranking with respect to requests from other devices. Requests are assigned positions in the ordinal ranking concurrent with other activity on the data bus. Substantially simultaneous requests are ordered sequentially. As control of the data bus is relinquished by one device, control is transferred to the device whose position in the ordinal ranking is contiguous with that of the relinquishing device. Delay in making this transfer is substantially eliminated.