SAM D21 External Interrupt Controller (EIC) Overview

The External Interrupt Controller (EIC) allows up to 16 external pins (EXTINTx) to be configured as interrupt lines. Each interrupt line can be individually masked and can generate an interrupt on rising, falling, or both edges, or on high or low levels.

Each external pin:

  • has a configurable filter to remove spikes,
  • can be configured to be asynchronous (in order to wake up the device from sleep modes where all clocks have been disabled), and
  • can also generate an event.

A separate, non-maskable interrupt (NMI) is also supported. An NMI cannot, as the name suggests, be disabled in firmware and will take precedence over any in-progress interrupt sources. NMIs can be used to implement critical device features, such as forced software reset, or other functionality where the action should be executed in preference to all other running code, with a minimum amount of latency.

A generic clock (GCLK_EIC) is required to clock the peripheral. This clock must be configured and enabled in the Generic Clock Controller before using the peripheral. This generic clock is asynchronous to the user interface clock (CLK_EIC_APB). Due to this asynchronicity, writes to certain registers will require synchronization between the clock domains.

EIC Block Diagram

EIC.png

 Learn More

 
EIC Configuration
Learn more >
 
EIC Example Project
Learn more >
© 2018 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contained on this site regarding device applications and the like is provided only for your convenience and may be superseded by updates.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.