Explanation:

DMA stands for direct memory access, which is a method of transferring data from one memory location to another without the involvement of the processor. In DMA, a dedicated DMA controller manages the transfer of data between the I/O device and the memory.

Interrupt mode is a method of handling I/O operations where the processor is involved in the transfer of data. In this mode, the processor receives an interrupt signal from the I/O device, which causes the processor to stop its current task and handle the interrupt. The processor then reads or writes data from or to the I/O device.

Differences between DMA and Interrupt mode:

1. Involvement of the processor:

In DMA, the processor is not involved in the transfer of data between the I/O device and the memory. Instead, a dedicated DMA controller manages the transfer.

In Interrupt mode, the processor is involved in the transfer of data. When an interrupt occurs, the processor stops its current task and handles the interrupt.

2. Method of accessing I/O devices:

In DMA, the DMA controller accesses the I/O device directly and transfers data to or from the memory.

In Interrupt mode, the processor accesses the I/O device and transfers data to or from the memory.

3. Amount of data transfer possible:

DMA allows for larger amounts of data to be transferred at a faster rate, as the transfer is managed by a dedicated controller.

In Interrupt mode, the amount of data that can be transferred is limited, as the processor has to handle the interrupt and manage the transfer.

Conclusion:

In summary, DMA and Interrupt mode are two different methods of handling I/O operations. DMA is faster and more efficient as it does not involve the processor in the transfer of data, while Interrupt mode involves the processor in the transfer of data.