Section 16.5
Review Questions
Multiple bus initiators and arbitration

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1. Why is it not enough for there to simply be a bus busy wire which is used as a kind of traffic light to keep other would-be bus initiators from attempting to use the bus when it is being used by another component?

2. What do we call the set of rules that govern the behavior of all bus devices to keep them from interfering with each other?

3. Besides some buses, where else might decentralized bus contention protocols be used?

4. What do we call the device that imposes centralized bus contention control?

5. Which wire is used by would-be bus initiators to tell this device that they want to use the bus?

6. Which wire is used to tell a component that it can act as initiator?

7. Which of the two wires in the previous two questions is really a group of wires, one for each would-be bus initiator?

8. What do we call one complete use of the bus, from initial request all way to the end of the use?

9. Make a totally fair arbiter is hard, one that randomly chooses the next bus initiator. What circuit have we seen so far could act as an arbiter for two devices?