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# 1.38 TrustZone EIC Pin Toggle

This example application demonstrates handling of external pin interrupt in secure and non-secure project.

## Description

This demonstrates TrustZone feature and uses two projects viz., Secure and Non-Secure Project that work together on the same MCU and offering security isolation between the Trusted and the Non-trusted resources in the device.

- Secure project uses an EIC pin to generate interrupt on rising edge and toggles the LED
- Non-secure project uses an EIC pin to generate interrupt on rising edge and toggle an GPIO pin
- Non-secure project also uses RTC to generate periodic event to toggle a GPIO pin

## Components Used

- EIC - Configured as Mix-Secure Peripheral for Secure EIC and Non-secure EIC interrupts
- Event System - Configured as Mix-Secure Peripheral for the Secure and Non-secure events
- RTC - Configured as Non-secure mode
- LED - Configured as Secure mode
- Two NON_SECURE_PIN - Configured as Non-secure mode

## Downloading and Building the Application

To clone or download this application from Github, go to the main page of this repository and then click Clone button to clone this repository or download as zip file. This content can also be downloaded using content manager by following these instructions.

Path of the application within the repository is as shown below:

Type | Path
--- | ---
Project group | apps/trustZone/eic/eic_pin_toggle
Secure Project | apps/trustZone/eic/eic_pin_toggle/Secure/firmware
Non-Secure Project | apps/trustZone/eic/eic_pin_toggle/NonSecure/firmware

To build the application, refer to the following table and open the project using its IDE.

Project Name | Description
--- | ---
sam_l11_xpro_Secure.X sam_l11_xpro_NonSecure.X | Secure and Non-secure MPLABX project for SAML11 Xplained Pro Evaluation Kit

## Setting Up the Hardware

The following table shows the target hardware for the application projects.

Project Name | Description
--- | ---
sam_l11_xpro_Secure.X sam_l11_xpro_NonSecure.X | SAML11 Xplained Pro Evaluation Kit

### Setting Up SAM L11 Xplained Pro Evaluation Kit

- Connect the Debug USB port on the board to the computer using a micro USB cable
- Connect an oscilloscope/Logic analyzer to monitor the PORT pin PA08 (Pin #14 on EXT1)
- Connect an oscilloscope/Logic analyzer to monitor the PORT pin PA17 (Pin #12 on EXT1)
- Tie a push button switch to PA09 (Pin #13 on EXT1) to drive the line LOW on switch press and also connect the same to the oscilloscope/logic analyzer

## Running the Application

1. Open the project group in the MPLAB X IDE and set the non-secure project as main project
2. Build and program the application
3. Observe the output for SAML11 Xplained Pro Evaluation Kit as follows:
   - LED0 is toggled on Switch (SW0) press using EIC interrupt in secure project
   - Pin PA08 is toggled on Switch (connected to PA09) press using EIC interrupt in non-secure project
   - Periodic RTC event (every ~32ms) toggles PA17 pin in non-secure project