Precautions When Using Hardware Watchdog Timer - Fujitsu F2MC-8FX Hardware Manual

CHAPTER 12 HARDWARE WATCHDOG TIMER
12.5

Precautions when Using Hardware Watchdog Timer

Care must be taken for the following points when using the hardware watchdog timer.
Precautions when Using Hardware Watchdog Timer
Stopping the hardware watchdog timer
Hareware watchdog is activated after reset. Once activated, the hardware watchdog timer cannot be stopped
until a reset is generated. Therefore, after reset, the hardware watchdog timer must be cleared within timer
interval.
Clearing the hardware watchdog timer
Clearing the RC oscillator prescalar also clears the counter of the hardware watchdog timer.
The counter of the hardware watchdog timer is cleared when entering the sleep mode, stop mode or watch
mode.
Programming precaution
When creating a program in which the hardware watchdog timer is cleared repeatedly in the main loop, set
the processing time of the main loop including the interrupt processing time to the minimum hardware
watchdog timer interval time or shorter.
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