TM4C1231H6PGE Datasheet, PDF (757/1192 Pages) Texas Instruments – Tiva™ TM4C1231H6PGE Microcontroller

Tiva^™ TM4C1231H6PGE Microcontroller
12
Watchdog Timers
A watchdog timer can generate a non-maskable interrupt (NMI), a regular interrupt or a reset when
a time-out value is reached. The watchdog timer is used to regain control when a system has failed
due to a software error or due to the failure of an external device to respond in the expected way.
The TM4C1231H6PGE microcontroller has two Watchdog Timer Modules, one module is clocked
by the system clock (Watchdog Timer 0) and the other (Watchdog Timer 1) is clocked by the PIOSC
The two modules are identical except that WDT1 is in a different clock domain, and therefore requires
synchronizers. As a result, WDT1 has a bit defined in the Watchdog Timer Control (WDTCTL)
register to indicate when a write to a WDT1 register is complete. Software can use this bit to ensure
that the previous access has completed before starting the next access.
The TM4C1231H6PGE controller has two Watchdog Timer modules with the following features:
■ 32-bit down counter with a programmable load register
■ Separate watchdog clock with an enable
■ Programmable interrupt generation logic with interrupt masking and optional NMI function
■ Lock register protection from runaway software
■ Reset generation logic with an enable/disable
■ User-enabled stalling when the microcontroller asserts the CPU Halt flag during debug
The Watchdog Timer can be configured to generate an interrupt to the controller on its first time-out,
and to generate a reset signal on its second time-out. Once the Watchdog Timer has been configured,
the lock register can be written to prevent the timer configuration from being inadvertently altered.
June 12, 2014
757
Texas Instruments-Production Data