We describe a protocol of input device communication below.
a. Each device has a distinct address
b. The bus controller scans each device in sequence of increasing address value to determine if the entity wishes to communicate.
c. The device ready to communicate leaves it data in IO register.
d. The data is picked up and the controller moves to step-a above.
Identify the form of communication best describes the IO mode amongst the following:
Source: nptel
(A) Programmed mode of data transfer
(B) DMA
(C) Interrupt mode
(D) Polling
Answer: (D)
Explanation: See Polling