Interrupts and Interrupt Handling

Have you ever wondered how computer components demand and get attention from the CPU? How do they tell the CPU or operating system that something important has just happened in the computer system, which requires an immediate response from the CPU, e.g., new data has just arrived at an I/O interface and should be processed immediately? This is done using so-called interrupts. This chapter will cover the theory and practice of interrupts and their handling. An interrupt is a hardware-initiated procedure that interrupts whatever program CPU is currently executing and requests that the CPU immediately start running another program that is written to service the particular interrupt request.