Describe the three data transfer modes (1) programmed I/o (2)
interrupt initiated i/o (3) DMA

Why does DMA have priority over the cpu when both request a memory transfer?

What do you mean by fault tolerance ?

What are MTTF and MTTR?

Why do we need DMA ? Draw the typical block diagram of a DMA
controller and explain how it is used for direct data transfer between
memory and peripherals???