Low Power Watchdog Timer Example

Demonstrates using the nanoring watchdog timer (WDT2) to wake-up from LP1
and/or reset the program

When the program starts LED3 is turned on (LP3 mode) and LED0 start blinking
continuously.

  - Open a terminal program to see interrupt messages.

    - SW1: Push SW1 to enter LP1 and wake-up based on watchdog timer's wake-up
           period (2 seconds).
           - While in LP1 LED0 stops blinking and LED1 turns on.
           - After approximately 2 seconds the watchdog wake-up period
             expires and wakes up to LP3 (LED3 on, LED0 continuous blinking).

    -  SW2: Push SW2 to enter LP1 and reset program based on watchdog timer's
            reset period (4 seconds).
            - While in LP1 LED0 stops blinking and LED1 turns on. After about
              4 seconds the watchdog reset period expires and resets the
              program. (LED3 blinks three times).

   -  SW3: Push SW3 to trigger a long delay and see the program restart by
           blinking LED3 three times.
           - During the delay LED0 will stop blinking.
           - This delay is long enough for the reset period to expire and
             trigger a reset (4 seconds).