The following features are provided in time-shared bus organization:

• Addressing: It must be possible to distinguish modules on the bus to determine the source and destination of data


• Arbitration: Any I/O module can temporarily function as “master”. A mechanism is provided to arbitrate competing request for bus control, using some sort of priority scheme.


• Time shearing: when one module is controlling the bus, other modules are locked out and if necessary suspend operation until bus access in achieved.

The bus organization has several advantages compared with other approaches:

• Simplicity: This is the simplest approach to multiprocessor organization. The physical interface and the addressing, arbitration and time sharing logic of each processor remain the same as in a single processor system.


• Flexibility: It is generally easy to expand the system by attaching more processor to the bus.


• Reliability: The bus is essentially a passive medium and the failure of any attached device should not cause failure of the whole system.