Hardware requirements

  • Micro USB cable

  • LPCXpresso55S28 board

  • Personal Computer

Board settings

No special settings are required.

Please note that, if you run the demo with the J10 unconnected, download maybe failed in the second time, please connect the J10 while debugging, then the CPU can be booted from ROM, otherwise, with the WWDT running, downloading maybe failed.

Prepare the Demo

Note: MCUXpresso IDE project default debug console is semihost

  1. Connect a micro USB cable between the host PC and the LPC-Link USB port (P6) on the target board.

  2. Open a serial terminal with the following settings:

    • 115200 baud rate

    • 8 data bits

    • No parity

    • One stop bit

    • No flow control

  3. Download the program to the target board.

  4. Either press the reset button on your board or launch the debugger in your IDE to begin running the demo.

Running the demo

If the demo run successfully, you will see the red LED blink every two seconds. The log below shows example output of the WWDT driver demo in the terminal window:

— Time out reset test start — Watchdog reset occurred

— Window mode refresh test start—

WDOG has be refreshed! WDOG has be refreshed! WDOG has be refreshed! WDOG has be refreshed! WDOG has be refreshed! WDOG has be refreshed! WDOG has be refreshed! WDOG has be refreshed! WDOG has be refreshed! WDOG has be refreshed! WDOG has be refreshed! WDOG has be refreshed! WDOG has be refreshed! WDOG has be refreshed!