DIAG_TIMER_COUNT_OVF_MAX

#define DIAG_TIMER_COUNT_OVF_MAX (uint16_t)  ( ( DIAG_TIMER_COUNT_REF + DIAG_MAX_DIFFERENCE ))

This is a macro to set the TC maximum number of overflows. This is a limit for the number of TC overflows. If this should be exceeded the RTC would be assumed to be faulty and the error handler would be called.