GD32F403xx User Manual
232
14.
Watchdog timer (WDGT)
The watchdog timer (WDGT) is a hardware timing circuitry that can be used to detect system
f ailures due to software malfunctions. There are two watchdog timer peripherals in the chip:
f ree watchdog timer (FWDGT) and window watchdog timer (WWDGT). They offer a
combination of a high safety level, flexibility of use and timing accuracy. Both watchdog timers
are offered to resolve malfunctions of software.
The watchdog timer will generate a reset when the internal counter reaches a given value.
The watchdog timer counter can be stopped while the processor is in the debug mode.
14.1.
Free watchdog timer (FWDGT)
14.1.1.
Overview
The f ree watchdog timer (FWDGT) has f ree clock source (IRC40K). Thereupon the FWDGT
can operate even if the main clock fails. It’s suitable for the situation that requires an
independent environment and lower timing accuracy.
The f ree watchdog timer causes a reset when the internal down counter reaches 0. The
register write protection function in free watchdog can be enabled to prevent it from changing
the configuration unexpectedly.
14.1.2.
Characteristics
◼
Free-running 12-bit downcounter.
◼
Reset when the downcounter reaches 0, if the watchdog is enabled.
◼
Free clock source, FWDGT can operate even if the main clock fails such as in standby
and Deep-sleep modes.
◼
Hardware f ree watchdog bit, automatically start the FWDGT or not when power on.
◼
FWDGT debug mode, the FWDGT can stop or continue to work in debug mode.
14.1.3.
Function overview
The f ree watchdog consists of an 8-stage prescaler and a 12-bit down-counter.
shows the functional block of the free watchdog module.