LZCO_522_C3B

What is the main disadvantage of programmed I/O compared to interrupt-driven I/O?

• It requires more memory.

• The processor has to wait and continuously check the I/O module.

• It does not use a control line.

• It has a complex interrupt handling process.

In interrupt-driven I/O, when does the processor check for interrupts?

• Only at system startup.

• After every few cycles.

• At the end of each instruction cycle.

• Only when I/O operations are required.

What is the purpose of saving the program counter (PC) and processor status word (PSW) during an interrupt?

• To initialize a new program.

• To ensure the I/O module completes its task.

• To resume the interrupted program accurately.

• To reset the processor for a new task.

What sequence does the processor follow when it receives an interrupt signal from an I/O device?

• Completes current instruction, acknowledges the interrupt, saves state, and loads the interrupt handler.

• Loads the interrupt handler, saves state, acknowledges interrupt, and completes the instruction.

• Saves state, completes current instruction, loads interrupt handler, and resumes work.

• Acknowledges interrupt, completes current instruction, loads interrupt handler, and saves state.

Which of the following is not a technique used to determine which device issued an interrupt?

• Multiple interrupt lines.

• Software poll.

• Daisy chain.

• Stack allocation.

What is the main disadvantage of using a software poll for identifying interrupting devices?

• It requires extra hardware.

• It is very time-consuming.

• It cannot handle multiple interrupts.

• It only works with certain I/O devices.

How does the daisy chain technique manage interrupts?

• Each I/O module has a dedicated line to the processor.

• I/O modules share a common interrupt request line with the interrupt acknowledge line passing through each module.

• It uses software polling.

• It assigns a priority level to each device.

What is the role of an interrupt vector in a daisy chain configuration?

• It identifies the type of I/O module.

• It stores the interrupted program's state.

• It points to the device-service routine for the interrupting module.

• It restarts the I/O operation.

Why is it essential to save all register contents during interrupt processing?

• To update the system control stack.

• To prevent data corruption from the interrupt handler's use of the same registers.

• To start a new program after handling the interrupt.

• To send them to the I/O module for processing.

What is a significant advantage of interrupt-driven I/O over programmed I/O?

• It allows for higher storage capacity.

• It eliminates the need for device drivers.

• It reduces the time the processor spends waiting for I/O operations.

• It enables faster data transmission speeds.