Deterministic arbitration of a serial bus using arbitration addresses

Abstract

An apparatus, system, and method for arbitrating for a serial bus in an efficient manner. An arbitration phase includes master devices asserting respective arbitration addresses on the serial bus after initiating communications sequences with a START condition. After the arbitration phase, the controlling master device conveys a data transfer upon the serial bus. The serial bus and the devices connected thereto may operate according to an I,C-compatable protocol. The arbitration address may correspond to a slave address associated with a slave device. Each arbitration address is preferably associated with only one master device. The arbitration address preferably initiates a READ cycle, and the slave device responds with a data byte. The data byte may be stored, discarded, or ignored by the master device, as desired. The arbitration address may not be associated with any slave device coupled to the serial bus. The master device is configured to continue the communications sequence without receiving acknowledge signals from a slave device during or after the arbitration phase. The master device continues the communications sequence with a repeated START condition and repeated address and data phases for the transfer of data. Each arbitration address may be associated with an arbitration device coupled to the serial bus. Acting as a slave device responsive to multiple slave addresses, the arbitration device may accept WRITE data and/or send READ data in response to receiving the arbitration address. The arbitration device properly acknowledges all addresses and data transfers in which it is involved.