I don’t use CAN2…. Are you observing this problem randomly? Yes. Could you fix when you are observing exactly this problem? Yes. How are you detecting the RTCH decreased content? I read value from RTCL RTCH every 1 sec. I suspect the following points: - What's the RTC basic clock frequency? May be you are not spying the RTCH register in real time. I have external clock 11.0592 MHz and I init RTCPH RTCPL regs. - Are you updating RTC registers in your code? Yes. If occasionally the RTCL RTCH register has decreases, I fixed it. - May be, you are unintentionally updating RTC registers? Neila, please… :) Regards, Pawel