10.2.5   Watchdog Timer+ Clock Fail-Safe Operation
The WDT+ module provides a fail-safe clocking feature assuring the clock to the WDT+ cannot be
disabled while in watchdog mode. This means the low-power modes may be affected by the choice for the
WDT+ clock. For example, if ACLK is the WDT+ clock source, LPM4 will not be available, because the
WDT+ will prevent ACLK from being disabled. Also, if ACLK or SMCLK fail while sourcing the WDT+, the
WDT+ clock source is automatically switched to MCLK. In this case, if MCLK is sourced from a crystal,
and the crystal has failed, the fail-safe feature will activate the DCO and use it as the source for MCLK.
When the WDT+ module is used in interval timer mode, there is no fail-safe feature for the clock source.






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