In order to go out of the Long Window and start the first watchdog sequence, the MCU must do the following before elapse of the Long Window time interval:

• Clear bits WD_PWRHOLD (more detail in Section 8.14.4)
• Apply a pulse signal with a minimum pulse-width t_{WD_pulse} on the pre-assigned GPIO pin in the case the watchdog is configured for Trigger mode, or
• Write four times to WD_ANSWER[7:0] in the case the watchdog is configured for Q&A mode

When the MCU fails to get the watchdog out of the Long Window before the configured Long Window time interval (t_{LONG_WINDOW}) elapses, the device goes through a warm reset, and sets the WD_LONGWIN_TIMEOUT_INT. This bit latched until the MCU writes a ‘1’ to clear it.