STM8L : why is the beginning of flash memory (0x8000 to 0x9200) erased/modified after power off ?(!)

[JPani.1]

Hello,

When I flash a user application to STM8L with STVD, it works fine. As long as I do NOT power off MCU, I can read back flash content with STVP. For the first byte located at address 0x8000 (beginning of IT vector table), value is 0x82, which is normal.

But, if I disconnect USB cable and reconnect it, and if I read flash content with STVP, the data have been modified and the first byte is not 0x82 any more ! Moreover, it seems that most of data are 0 (not all of them) from address 0x8000 to 0x9200.

I replaced my user application by a simple one, let's say an "empty main function", and the issue is still there.

Any idea ? Thank you in advance for any help... 🙂

Julien

[Philipp Krause]

Do you see the same problem when using stm8flash instead of STVD? What about writing with one and reading with the other?

[JPani.1]

Hello Philipp,

Thank you very much for your help.

I was using SVTD & SVTP on Windows 10. I followed your suggestion and tried with stm8flash, which I installed on another laptop running Ubuntu : I flashed a s19 file and read back memory successfully after unplugging/plugging back the device through USB. So, flash content is not erased any more. Congratulations for your good suggestion. 🙂

However, if I flash the device through stm8flash on Ubuntu, and if I disconnect the device for plugging it to the laptop running SVTP on Windows 10, the flash is still corrupted at SVTP reading. Do you think that it is a SVTP problem or rather a specific Windows 10 issue ? (that's just a bonus question, stm8flash workaround is already a very good thing for me)

Julien

[JPani.1]

PS : I did some others tests and it seems that memory corruption appears after a connexion to my laptop running Windows 10 (SVTP is not the problem). Weird, anyway... ^^

Thank you again for your help !

Best,

Julien