Bus protocol and method for controlling a data processor

A bus protocol uses signals to designate a bus transfer termination (BTT*) and a bus grant relinquish (BGR*). The BTT* signal is an output which is asserted by a bus master which currently has ownership of a bus to indicate to other potential bus masters that a bus transfer is complete and that bus ownership may be transferred to another bus master. The BGR* signal is an input to a bus master. When BGR* is asserted, a bus arbiter/controller is informing the current bus master that the bus must be relinquished as soon as possible, after the deassertion of the Bus Grant signal, with no regard for locked sequences. If BGR* is deasserted, the bus arbiter is informing the current bus master that the bus can be relinquished at a time which is convenient for the current bus master. In general, BGR* is a bit which indicates the urgency of a pending bus ownership transfer.