If the CPU is idle while a device completes an access request, the CPU cycles that could have been (but weren't) devoted to instruction execution are called ____.
A) I/O channels
B) I/O hooks
C) I/O wait states
D) I/O peers

Question

Quizplus · Accepted Answer

The cycles that were not used by the CPU while it was idle waiting for an I/O device to complete its access request are called I/O wait states. These wait states typically occur when the CPU has to wait for slow devices to complete read or write operations. During the wait states, the CPU is inactive and cannot execute instructions. Therefore, the CPU is said to be "waiting" for the I/O device to complete its operation. A and D are not relevant to the question, and B is not a commonly used term in this context.

If the CPU Is Idle While a Device Completes an Access