MSP430FR6879: FRAM Uncorrectable FRAM bit error detection SYSSNIV Interrupt

Hello,

On some devices with MSP430FR6879 I get interrupt SYSSNIV Uncorrectable FRAM bit error.

But CRC above memory is fine.

So far discovered about 10 pieces from batch 1000 pcs.

The device uses LPM3 and 1 MHz MCLK

PMM29 is implemented.

//-------------------------------------------------------------------------
// FRAM
//-------------------------------------------------------------------------
  FRCTL0 = FRCTLPW; // unlock FRAM control
    // enable NMI correctable & uncorrectable bit error
    // ERRATA PMM29 -> clear the FRLPMPWR
  GCCTL0 = UBDIE + CBDIE + FRPWR + 0;
  FRCTL0_H = 0; // lock FRAM control

In the past, MSP430FR6979 was used and the error never occurred.

Except this fault, everything else is fully functional.

Any idea ....