Answer to Question #265515 in Computer Networks for GOWTHAM

Question

Explain any two methods of accessing 1/0 devices and transferring data from them

Answer 1

Programmed I/O

Programmed I/O methods control the transfer of data between the connected device and the computer. Each I/O device connected to the computer continuously checks for input. As soon as it receives an input signal from the device, it makes this request until it stops receiving the input signal. Let's say you want to print a document. When you choose to print from your computer, a request is sent through the central processing unit (CPU), a communication signal is acknowledged and sent to the printer.

Interrupt-Based I/O

Interrupt-based I/O controls the transfer of data to and from the connected I/O device. Instead, it allows the CPU to continue other tasks and only stops when it receives an input signal from an I/O device. For example, when a key on the keyboard is pressed, an I/O interrupt signals the CPU to suspend the current task and executes the request.