SAM L10/L11 Event System (EVSYS)

Event System Overview

The Event System (EVSYS) is part of the SAM L10/L11 architecture, it allows autonomous, low-latency, and configurable communication between peripherals.

Several peripherals can be configured to generate and 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 receive events from multiple generators, and generate events for multiple users.

Communication is made without CPU intervention and without consuming bus or RAM bandwidth. This reduces the load of the CPU and other system resources, compared to a traditional interrupt-based system.

Event System Features

  • Eight configurable event channels:
    • All channels can be connected to any event generator
    • All channels provide a pure asynchronous path
    • Four channels (CHANNEL0 to CHANNEL3) provide a resynchronized or synchronous path using their dedicated generic clock (GCLK_EVSYS_CHANNEL_n)
  • 49 event generators
  • 23 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
  • Optional Static or Round-Robin interrupt priority arbitration
  • Each channel and each event user can be configured as secured or non-secured (SAM L11)

The following figures compare a system WITHOUT an Event System to a system WITH an Event System. The first figure shows that for a typical application, the CPU is quickly busy and overloaded, while in the second figure, the Event System, allows all the peripherals to interact without requiring CPU intervention until a relevant event occurs.

Refer to the related links to these peripherals at the page bottom to get more details and examples.

Animated GIF of a System WITHOUT Event System


Animated GIF of a System WITH Event System


Event Generator/ User (a few examples):


You will find several code examples for each peripheral listed in "Peripherals" section of the SAM L10/L11 Family Training.


Low Power Techniques
Learn more >
SAM L10 L11 family page
Learn more >
© 2024 Microchip Technology, Inc.
Notice: ARM and Cortex are the registered trademarks of ARM Limited in the EU and other countries.
Information contained on this site regarding device applications and the like is provided only for your convenience and may be superseded by updates. It is your responsibility to ensure that your application meets with your specifications. MICROCHIP MAKES NO REPRESENTATIONS OR WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY OR OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY OR FITNESS FOR PURPOSE. Microchip disclaims all liability arising from this information and its use. Use of Microchip devices in life support and/or safety applications is entirely at the buyer's risk, and the buyer agrees to defend, indemnify and hold harmless Microchip from any and all damages, claims, suits, or expenses resulting from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual property rights.