In programmed I/O, who typically controls each data transfer between the CPU and the I/O device?

Options

  • A. The CPU
  • B. The DMA controller alone
  • C. The hard disk controller without CPU instructions
  • D. The cache controller
  • E. None of the above

Correct Answer (Detailed Explanation is Below)

A. The CPU

Detailed Explanation

Explanation: In programmed I/O, the CPU executes instructions to check device status and perform data transfers. This differs from DMA, which handles block transfers with less CPU intervention.