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MCHP

RSWDT timeout

This example shows how to generate a RSWDT reset by emulating a deadlock.

Description

This example demonstrates the usage of Reinforced Safety Watchdog Timer to avoid system deadlock. The simplest way to emulate a deadlock is to wait in an infinite loop. The application enters such an infinite loop when the switch is pressed. As a result the RSWDT counter is not cleared within a bounded time configured using MHC. The RSWDT peripheral will trigger a system reset as the counter exceeds the specified time band.

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 apps/rswdt/rswdt_timeout/firmware .

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

Project Name Description
sam_e70_xult.X MPLABX Project for SAM E70 Xplained Ultra board
sam_v71_xult.X MPLABX Project for SAM V71 Xplained Ultra board
   

Setting up the hardware

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

Project Name Board
sam_e70_xult.X SAM E70 Xplained Ultra board
sam_v71_xult.X SAM V71 Xplained Ultra board
   

Setting up SAM E70 Xplained Ultra board

  • Connect the Debug USB port on the board to the computer using a micro USB cable

Setting up SAM V71 Xplained Ultra board

  • Connect the Debug USB port on the board to the computer using a micro USB cable

Running the Application

  1. Open the Terminal application (Ex.:Tera term) on the computer
  2. Connect to the EDBG Virtual COM port and configure the serial settings as follows:
    • Baud : 115200
    • Data : 8 Bits
    • Parity : None
    • Stop : 1 Bit
    • Flow Control : None
  3. Build and Program the application project using its IDE
  4. The console displays the following message

    output

  5. Press the switch to put the system in a deadlock
  6. LED should stop blinking and the console should print the following message

    output

  7. RSWDT will reset the device in four seconds and the demonstration should restart

The following table provides the LED and switch names

Board LED Switch
SAM E70 Xplained Ultra board LED1 SW0
SAM V71 Xplained Ultra board LED0 SW0
     


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