BUS ARBITRATION

The device that is allowed to initiate data transfers on the bus at any given time is called the bus master. When the current master relinquishes the control of the bus another device can acquire the status. Bus arbitration is the process by which the next device to become the master of the bus is selected and the bus mastership is transferred to it. The selection of the bus master must tale into accounts the needs of various devices bt establishing a priority system for gaining access to the bus.

There are two approaches to the process called bus arbitration. They are centralised bus arbitration and distributed bus arbitration. In centralized arbitration a single bus arbitrer performs the required arbitration.In distributed arbitration all the devices participate in the selection of the bus master.