Enabling AUXVCC3 gives RTC_C error interrupt RTCOFIFG MSP430F6779

Hello Abhishek,

The RTCOFIFG bit flag indicates failure of the 32-kHz crystal oscillator and stores a failure event that occurred while the RTC was operating on the backup supply from AUXVCC3. Make sure that the AUXVCC3 pin is properly connected as explained in Section 4.1 of the User's Guide and that LFXT1 has been initialized properly in your code, including the XT1 fault flag loop.

Regards,
Ryan

Hello Ryan Brown,
I am using AUXVCC3 internally by this code.


AUX3CHCTL = AUXCHKEY + AUXCHEN + AUXCHC_1 + AUXCHV_1;

Is there any need to apply externally? Can't i use internal supply?

Thanks for the reply..
I will check after applying and let you know if it is operating correctly or not.

Regards,
Abhishek Parikh

Hello Ryan,
I am not enabling RTCOFIE should RTCOFIFG flag come?
thanks

Hello Ryan,

I have connected AUXVCC3 and stopped my internal AUXVCC3 and checked but output is same.

Another thing i have noticed when I am enabling AUXVCC3 by external or internal my program stuck in clock configuration.

UCSCTL6 &= ~(XT1OFF); // Enable XT1
UCSCTL6 |= XCAP_3; // Internal load cap

// Loop until XT1, XT2 & DCO fault flag is cleared
do
{
UCSCTL7 &= ~(XT2OFFG | XT1LFOFFG | DCOFFG); //here my program stuck
// Clear XT2,XT1,DCO fault flags
SFRIFG1 &= ~OFIFG; // Clear fault flags
} while (SFRIFG1 & OFIFG);

Thanks
Regards
Abhishek Parikh

Hello Abhishek,

Even if the RTCOFIE is not enabled the RTCOFIFG will still become set when it detects crystal failure. The only difference is that the flag will not force the program to enter the RTC ISR. If your program is stuck in the clock configuration then this is further proof that your crystal hardware is faulty or not being driven properly. Are you using a TI-provided EVM or a custom-designed board? Are the traces between the crystal and the XIN/XOUT pins symmetrical and as short as possible? Are you using the proper loading caps? Try swapping crystals if possible.

Regards,
Ryan

Hello Ryan Brown1


Yes my AUXVCC3 is connected properly and initialized properly also.

Please go through https://e2e.ti.com/support/microcontrollers/msp430/f/166/t/453023  for more detail.

Thanks
Regards
Abhishek Parikh