1. Are you able to read the data back from flash in the next power cycle after the power failure?
2. After the sudden power failure does the VCC voltage of flash devices become 0V? Can you capture the VCC waveform during the sudden power down?
3. How does the MCU behave after a communicate failure? Does it write any data to flash, when communication failure happens?
4. Are you reading any data from flash during power up?
Thanks and Regards,