Thus the processor is involved only at the beginning and end of the transfer. During that time the processor is suspended.

It is not required to complete the current instruction to suspend the processor. The processor may be suspended just after the completion of the current bus cycle. On the other hand, the processor can be suspended just before the need of the system bus by the processor, because DMA controller is going to use the system bus, it will not use the processor.

The point where in the instruction cycle the processor may be suspended shown in the Figure 6.10.