Chapter 5 Exceptions, Interrupts, and Initialization
In the MIPS architecture interrupts, traps, system calls, and everything else that can disrupt the normal flow of execution are called exceptions and are handled by a single mechanism. What sort of events are they?
External events: Some event outside the CPU core—that is, from some real “wire” input signal. These are interrupts.1 Interrupts are used to direct the attention of the CPU to some external event: an essential feature of an OS that attends to more than one different event at a time.