What is mean by bus arbitration? List different types of bus arbitration.

Bus arbitration is the process of deciding which device becomes the bus master when several devices ask for the shared bus at the same time. Only one master can use the bus at a time.

Two types of bus arbitration exist.

• Centralized arbitration: a single arbiter or the CPU grants the bus. It has the daisy chaining method, the polling method and the independent request (parallel) method.
• Distributed arbitration: there is no central arbiter. Every device has its own arbitration logic, and the devices decide by themselves using a priority code placed on the bus.