23.4.4 Reset State Priorities

The reset state manager manages the following priorities between the different reset sources, given in descending order:

  • Backup reset
  • Wake-up reset
  • Watchdog reset
  • 32.768 kHz Crystal Oscillator Failure Detection reset
  • Software reset
  • User reset

Particular cases are listed below:

  • When in user reset:
    • A watchdog event is impossible because the watchdog timer is being reset by the processor reset signal.
    • A software reset is impossible, since the processor reset is being activated.
  • When in software reset:
    • A watchdog event has priority over the current state.
    • The NRST has no effect.
  • When in watchdog reset:
    • The processor reset is active and so a software reset cannot be programmed.
    • A user reset cannot be entered.