Why can I access 0x0810000 AXIM address in STM32F767ZG Flash , although the reference manual says that its only till 0x080F FFFF?

[Mr.Embedded]

I am using STM32F767ZG for a project of mine. As per page 89 of the reference manual , it has 1 MB of flash and has a flash organization structure, as shown in the screenshot. The manual says that the "Main memory block" is limited to 0x080F FFFF. I am using ST-Link utility now, and I can access ( read and flash) 0x0810000 address space. This address space should be available only for STM32F767ZI variants (2MB Flash), right ? Does this mean that my chips are 2MB (STM32F767ZI) instead of 1MB (STM32F767ZG), although they are marked as STM32F767ZG ?

Edit 1 : I using an RTOS, and it seem like the flash driver can indeed access these flash sectors, which should not technically exist. Strangely STM32Cube programmer does not show me those memory locations however ST-Link utility does allow me to access them.

[Peter BENSCH · Accepted solution]

Welcome, @Mr.Embedded​, to the community!

Similar questions have been asked and discussed many times, e.g. here and there.

The larger memory may well be physically present, but ST only guarantees functions that have been successfully tested. If you use the untested area and/or functions and are then exposed to warranty claims yourself because of the failed device and damage incurred, you must realize that you are entirely responsible. So, if you want to work professionally, we strongly recommend using only the functions and areas that are also tested and guaranteed.

BTW: The ST-LINK utility (STSW-LINK004) is already on status NRND and should definitely not be used anymore, also because it does not know the newly added STM32 members. The STM32CubeProgrammer checks the target platform more exactly and rightly does not allow access to untested areas for the reasons mentioned above.

Does it answer your question?

Regards

/Peter

[Mr.Embedded]

Thanks Peter, for the quick help. Saved my day 🙂

[Piranha]

> 0x0810000

You cannot access this address at all - it misses one zero at the end. Be careful with numbers! 😉