单选题：Which of the following is NOT true regarding a device that uses
Which of the following is NOT true regarding a device that uses interrupt-driven I/O？@[A](1)
A. The CPU must continously check whether the current I/O operation is done.
B. The CPU is informed through an interrupt request line when the current I/O operation is done.
C. I/O on the device can be overlapped with computation on CPU by other processes.
D. A device status table is necessary to save information about pending I/O requests.
A.The CPU must continously check whether the current I/O operation is done.
B.The CPU is informed through an interrupt request line when the current I/O operation is done.
C.I/O on the device can be overlapped with computation on CPU by other processes.
D.A device status table is necessary to save information about pending I/O requests.
答案：A
A. The CPU must continously check whether the current I/O operation is done.
B. The CPU is informed through an interrupt request line when the current I/O operation is done.
C. I/O on the device can be overlapped with computation on CPU by other processes.
D. A device status table is necessary to save information about pending I/O requests.
A.The CPU must continously check whether the current I/O operation is done.
B.The CPU is informed through an interrupt request line when the current I/O operation is done.
C.I/O on the device can be overlapped with computation on CPU by other processes.
D.A device status table is necessary to save information about pending I/O requests.
答案：A