SLAU847D October 2022 – May 2024 MSPM0L1105 , MSPM0L1106 , MSPM0L1227 , MSPM0L1228 , MSPM0L1228-Q1 , MSPM0L1303 , MSPM0L1304 , MSPM0L1304-Q1 , MSPM0L1305 , MSPM0L1305-Q1 , MSPM0L1306 , MSPM0L1306-Q1 , MSPM0L1343 , MSPM0L1344 , MSPM0L1345 , MSPM0L1346 , MSPM0L2227 , MSPM0L2228 , MSPM0L2228-Q1
The primary function of the window watchdog timer (WWDT) is to initiate a reset when correct operation of the device has failed due to an unexpected software or system delay. The WWDT can be programmed with a predefined time window within which the application software must restart the timer, indicating that application execution is proceeding normally. If application software fails to restart the timer within the specified window, the WWDT will issue a WWDT violation signal to SYSCTL to generate a reset.
If watchdog functionality is not required in an application, the WWDT can also be configured as a basic system interval timer which is capable of generating periodic maskable interrupts to the CPU.
Key features of the WWDT include:
Devices may have 1 or 2 WWDT instances. A WWDT0 violation generates a BOOTRST, which resets the peripheral and CPU state and also causes the boot configuration routine (BCR) to run. A WWDT1 violation generates a SYSRST, which resets the peripheral and CPU state but does not trigger execution of the BCR. As such, WWDT1 is well suited for recovering from execution stalls that result from software execution, while WWDT0 is well suited for catching larger issues such as a corrupted trim value, at the expense of a longer reset time.