STM32L4: Read Out Protection Level

[TNaka.0]

Hi, I use STM32L431CCT6 for development.

Occasionally, even I have no done any special operation, read out protection mode is enabled.

(Level0→Level1)

I do not know the cause clearly.

Please tell me the cause or ​reproduction method.

And is there any solution to this problem?

[Tesla DeLorean]

As reported by what software?

Any diagnostic or telemetry output from the device where you can understand the process or commonality to the failure?

Testing the options bits in your own software to observe if this is occuring?

How frequently is this occurring?

How many chips/boards is this being observed on?

Discussed with your local FAE?

Been using the L432 for a couple of months without issue. Using the STM32 Cube Programmer app to download code.

[TNaka.0]

This problem is occurring in the program I created for development.

But my program does not set ROP(Read Out Protection).

Reproduction frequency is 1 or 2 times in several hundred trials.

I confirmed that POR is enabled by ST-LinkUtiliry.

this problem is being observed on three chips.

Is there processing such as automatically enabling ROP mode on the MCU side when detecting something abnormal?

[Tesla DeLorean]

The Flash Demonstrator occasionally reported this when it had comms errors.

I'm not personally familiar with the failure modes, you check the errata, but realistically you should work with the FAE out of your local sales office, or start an online support request vis st.com.