Datasheet

24. EVSYS – Event System
24.1 Overview
The Event System (EVSYS) allows autonomous, low-latency and configurable communication between
peripherals.
Several peripherals can be configured to generate and/or respond to signals known as events. The exact
condition to generate an event, or the action taken upon receiving an event, is specific to each peripheral.
Peripherals that respond to events are called event users. Peripherals that generate events are called
event generators. A peripheral can have one or more event generators and can have one or more event
users.
Communication is made without CPU intervention and without consuming system resources such as bus
or RAM bandwidth. This reduces the load on the CPU and other system resources, compared to a
traditional interrupt-based system.
24.2 Features
• 12 configurable event channels, where each channel can:
– Be connected to any event generator.
– Provide a pure asynchronous, resynchronized or synchronous path
• 74 event generators.
• 29 event users.
• Configurable edge detector.
• Peripherals can be event generators, event users, or both.
• SleepWalking and interrupt for operation in sleep modes.
• Software event generation.
• Each event user can choose which channel to respond to.
24.3 Block Diagram
Figure 24-1. Event System Block Diagram
PERIPHERALS
EVSYS
USER
MUX
PERIPHERALS
GCLK
GENERATOR
EVENTS
CLOCK REQUESTS
USERS EVENTS
EVENT
CHANNELS
SAM D21 Family
EVSYS – Event System
© 2018 Microchip Technology Inc.
Datasheet Complete
DS40001882D-page 437