Which of the following is responsible for transferring the data between Input/Output devices and main memory

The correct answer is Option 4) DMA controller.

Key Points

• DMA (Direct Memory Access) Controller is responsible for directly transferring data between I/O devices and the main memory without CPU intervention.
• This improves system efficiency and frees up the CPU to perform other tasks while the data transfer is managed independently by the DMA controller.
• DMA is especially useful for high-speed devices such as hard drives, sound cards, and network cards.
• The CPU initiates the DMA transfer by specifying the source, destination, and size, and then the DMA controller takes over the actual data movement.

Additional Information

• Option 1 – Cache controller: Manages communication between cache memory and CPU, not I/O transfers.
• Option 2 – Math coprocessor: Handles complex arithmetic operations like floating-point calculations; not related to data transfer.
• Option 3 – Control Unit: Directs operations of the processor but does not handle actual data movement between I/O and memory.
• Benefits of DMA:
  • Faster data transfer
  • Reduced CPU load
  • Improved system performance