SWRU626 December 2025 CC3501E , CC3551E
The Watchdog Timer (WDT) is used to regain control when the system has failed due to a software error or due to the failure of an external device to respond in the expected way during sleep. The WDT supports 2 thresholds: the first (31b) generates an event (this is reserved for TI SW) and the second (23b with 8 bit resolution) generates a reset when a time-out value is reached. The WDT relies on a working LFCLK.
The WDT can be configured using the following sequence of writes and reads in the HOSTMCU_AON.ELPTMREN register: Halt (ELPTMRRST=1) Verify halted (Read VAL=0) Unhalt (ELPTMRRST=0) Reset counter value (ELPTMRLD=1) Start (ELPTMRSET) Verify started (VAL=1).
The reset bit (ELPTMREN[3] ELPTMRRST) takes precedence over start bit (ELPTMREN[2] ELPTMRSET), if both are set, the timer is halted.