Answer:
(a) Difference in data transfer rates
(b) Difference in word lengths
(c) Different peripherals with different modes of operation
Explanation:
There are several reasons. Some of them have been listed in the explanation section. A brief explanation is as follows
(a) Difference in data transfer rates
Some peripherals have fast transfer rate while some have slow transfer rates compared to the processor they are being connected to. This difference in the rates implies that a high speed system bus will find it difficult to communicate with a (say) low speed peripheral.
(b) Difference in word lengths
Another consideration is the word lengths. Often times, peripherals and the bus they are being connected with will have a different word lengths.
(c) Different peripherals with different modes of operation
In computer architecture, a processor can not be used to interact with peripheral of different mode of operations. In other word, each peripheral have its own mode and will require different means of connection.
