Q. Define Interrupts and Instruction Cycle?

Let's precise the interrupt process, on the event of an interrupt, an interrupt request (in form of a signal) is concerned to CPU. The CPU on receipt of interrupt request postpones the operation of currently executing program saves context of currently executing program and starts executing program that services which interrupt request. This program is termed as interrupt handler also. After the interrupting condition/ device has been serviced execution of original program is resumed.

So an interrupt may be determined as interruption of execution of an ongoing user program. Execution of user program resumes the instant interrupt processing is completed. So the user program doesn't comprise any code for interrupt handling. This job is to be performed by processor and operating system which in turn is also accountable for suspending execution of the user program and afterwards interrupt handling resumes user program from point of interruption.