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GD32L23x User Manual
243
15.
Watchdog timer (WDGT)
The watchdog timer (WDGT) is a hardware timing circuitry that can be used to detect system
failures due to software malfunctions. There are two watchdog timer peripherals in the chip:
free 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 (or an interrupt in window watchdog timer) when the
internal counter reaches a given value. The watchdog timer counter can be stopped while the
processor is in the debug mode.
15.1.
Free watchdog timer (FWDGT)
15.1.1.
Overview
The Free watchdog timer (FWDGT) has free clock source (IRC32K). 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 Free watchdog timer causes a reset when the internal down counter reaches 0 or the
counter is refreshed when the value of the counter is greater than the window register value.
The register write protection function in free watchdog can be enabled to prevent it from
changing the configuration unexpectedly.
15.1.2.
Characteristics
Free-running 12-bit down counter.
Generate reset in two conditions when FWDGT is enabled:
–
Reset when the counter reached 0.
–
The counter is refreshed when the value of the counter is greater than the window
register value.
Free clock source, FWDGT can operate even if the main clock fails such as in standby
and Deep-sleep modes.
Hardware free 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.
15.1.3.
Function overview
The free watchdog consists of an 8-stage prescaler and a 12-bit down counter.