ABSTRACT
The interrupt system of a microprocessor is the key to allowing programs to respond immediately to external events. An interrupt is an event (technically, a signal) that can interrupt the ²ow of the currently running program. Interrupts can be triggered by external or internal signals; they can be caused by so‘ware or hardware. e interrupt system provides a mechanism whereby a normally executing program can be suspended temporarily (between instructions) to allow a high-priority task to run. When the task is completed, the original program resumes. is is a bit like a function call and return, however, in the case of interrupts, there is no explicit call statement, and the interrupt invocation can occur at virtually any location in a program. When a program is interrupted, the routine that is executed in response to the interrupt is called an interrupt service routine, or interrupt handler. e process of interrupting the current program, executing the interrupt handler, and returning, is called servicing the interrupt.
