2.1.2.6 TC_MIN_COUNT_BEFORE_ERROR

#define TC_MIN_COUNT_BEFORE_ERROR (5U)

The minimum overflow value of TMR0 before WDT is allowed to reset the device is approximately 5 ms, considering the frequency tolerance. WDT time-out is 8 ms - 35% frequency tolerance of the clock. TC_MIC_COUNT_BEFORE_ERROR is 8 ms - 35% tolerance = 8 ms / 2.8 ms = 5.2 ms (5 ms).