AVR1001: Getting Started With the XMEGA Event System

The XMEGA event system is a set of features that allows peripherals to interact without intervention from the CPU. Several peripheral modules can generate events, often on the same conditions as interrupt requests. These events are routed through the event routing system to the event users, where certain actions can be triggered by the event. The CPU is not involved in this process, except in the setup phase. As an example, it is possible to trigger a Timer/Counter input capture when a user presses a button, or start an analog to digital conversion at the overflow of a timer/counter. When fully utilizing the power of the event system, it is possible to configure the chip to do complex operations, with very little intervention from the CPU, saving both valuable program memory and execution time.