Shown below is a bus system with a central arbiter that handles four devices. The device priorities range from highest for Device 4 down to the lowest for Device 1. The arbiter grants access to the highest present request. Each device has a separate request and grant line. The total available bus bandwidth is 80 MB/s. Each device wants to use 30MB/s of bus bandwidth. If a device is not granted access to the bus, it tries again as soon as the bus is not busy and keeps trying until it gets access. How much bus bandwidth will Device 1 be able to use and how much bus bandwith will Device 3 be able to use if:

a) Bus access is granted strictly on a priority basis?

Device 1 bandwidth = ------------- Device 3 bandwidth = ------------------

b) The bus arbiter grants access based on a fairness basis?

Device 1 bandwidth = ------------- Device 3 bandwidth = ------------------