Interrupt Processing
Consider the steps involved in IO interrupt when a device completes IO operation.
1.. CPU initiates IO operation to a device and goes about its normal processing.
2. Device completes IO and sends interrupts signal to the processor.
3. Processor completes current instruction before responding to the interrupt.
4. Processor determines the source of interrupt and sends acknowledgement.
5. Processor them saves its current state and transfers control to interrupt handler.