Flash reading, if MCU is read protected

[matic]

Posted on June 09, 2016 at 22:16

Hi.

When read protection level 1 is applied to MCU, is it possible to read flash content somehow?

I would like to store CPU status register, PC and some other variables into flash in case of hard fault. But MCU was read protected with level 1 before. If I get such (defected) part back, is it possible to read those statuses and variables from flash? I would have one dedicated flash page only for that.

Or is it maybe possible to leave only that page unprotected?

Thanks

[Tesla DeLorean]

Posted on June 09, 2016 at 22:21

It is a binary option, and only your own code running in Flash can read the content. You will have to code your own methods to exfiltrate the data you have stored there.

[matic]

Posted on June 10, 2016 at 06:05

So, it is not possible to read that page, if I connect the part to the debug port? Am I correct?

[Tesla DeLorean]

Posted on June 10, 2016 at 18:30

I think I've been pretty clear, if you feel the need to validate what I'm saying you should experiment and draw your own conclusions.