Today I received a product that was returned for repair. After checking the hardware, it was found that the MCU was not running normally. Through Simplicity Studio software, I found that the first page of Flash data is all FF. But I can't confirm how this phenomenon happened. Now I ask everyone for help, thank you.
without detailed hardware and software information, it was hard to draw conclusion what may cause this issue.
You may consider to check each items listed in below KBA:
The final result of the software part of BKA you provided is the formation of three officially recommended Flash operation functions. I used them.
Many of the reasons mentioned in the hardware section are illusory, and this kind of failure is basically unexplainable. Only more safety measures can be taken to avoid it, but it cannot be eliminated 100%.
Can you share your layout and schematic files for the board? Has only one board failed in this way?
There are 12 identical modules, and only 1 of them has a problem at present. There are hundreds of all products using EFM8, and there are 4 similar problems.
I recommend placing the bypass capacitors on VDD as close to the chip as possible. What powers the chip? Is it subjected to sudden power loss or electrical noise? Both of these can potentially cause flash corruption.