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GD32F20x User Manual
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16.
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.
16.1.
Free watchdog timer (FWDGT)
16.1.1.
Overview
The free watchdog timer (FWDGT) has free 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 free 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.
16.1.2.
Charateristics
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 free watchdog bit, automatically start the FWDGT at power on.
FWDGT debug mode, the FWDGT can stop or continue to work in debug mode.
16.1.3.
Function overview
The free watchdog consists of an 8-stage prescaler and a 12-bit down-counter. Refer to the
figure below for the functional block of the free watchdog module.
Summary of Contents for GD32F20 Series
Page 191: ...GD32F20x User Manual 191 Bits Fields Descriptions 31 0 TRNDATA 31 0 32 Bit Random data ...
Page 290: ...GD32F20x User Manual 290 conversion is ongoing ...
Page 325: ...GD32F20x User Manual 325 15 0 ALRM 15 0 RTC alarm value low ...
Page 385: ...GD32F20x User Manual 385 ...
Page 523: ...GD32F20x User Manual 523 clears AERR bit by writing 0 to it ...