MCQ IN COMPUTER SCIENCE & ENGINEERING

Detailed explanation-1: -The interrupt-based method, which controls the data transfer activity to and from connected I/O devices.

Detailed explanation-2: -A transfer from I/O device to memory requires the execution of several instructions by the CPU, including an input instruction to transfer the data from device to the CPU and store instruction to transfer the data from CPU to memory.

Detailed explanation-3: -This type of data transfer technique is known as DMA or direct memory access. During DMA the CPU is idle and it has no control over the memory buses. The DMA controller takes over the buses to manage the transfer directly between the I/O devices and the memory unit.

Detailed explanation-4: -I/O device operates asynchronously with CPU, interrupts CPU when finished. The advantage to this method is that every instruction which can access memory can be used to manipulate an I/O device. Memory mapped IO is used for most high-speed I/O devices like disks, communication interfaces.

Detailed explanation-5: -DMA Data Transfer Scheme Transferring bulk data using a microprocessor consumes more time. Therefore, the microprocessor performs the data transfer between an I/O device and memory using this DMA technique.