UM0306 Window watchdog (WWDG)
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Figure 23. Window watchdog timing diagram
11.5 Debug mode
When the microcontroller enters debug mode (Cortex-M3 core halted), the WWDG counter
either continues to work normally or stops, depending on DBG_WWDG_STOP configuration
bit in DBG module. For more details, refer to Section 20.15.2: Debug support for timers and
watchdog and bxCAN.
T6 bit
Reset
W[6:0]
T[6:0] CNT downcounter
time
Refresh WindowRefresh not allowed
3Fh
The formula to calculate the timeout value is given by:
where:
T
WWDG
: WWDG timeout
T
PCLK1
: APB1 Clock period measured in ms
Min-max timeout value @36MHz (PCLK1)
WDGTB Min Timeout Value Max Timout Value
0 113 µs 7.28 ms
1 227 µs 14.56 ms
2 455 µs 29.12 ms
3 910 µs 58.25 ms
T
WWDG
T
PCLK1
4096× 2
WDGTB
× T5:0[]1+()×= ms();