Flash READ & WRITE works even beyond specified size!

[hongjo]

Dear ST 
We are currently proceeding with development using the STM32H743VGT6.
As you can see in the datasheet, the STM32H743VGT6 has a built-in 1M flash.

I confirmed that it operates normally even though the flash partition was divided as shown below for the FOTA function.

and 
Confirmed normal operation of arbitrary 0xFFFF0F0 Write/Read at address 0x8140030 in the Storage area.

Therefore, to check if the MCU with 2MB Flash was incorrectly mounted on the PCB, I disassembled the device and examined the STM MCU part number under a microscope, confirming that it is an STM32H743VGT6 as shown in the figure below

And by referring to the RM04033 reference manual and reading the flash size as shown below, I confirmed that it has 1MB of Flash.

The register values ​​and product name on the STM32H743VGT6 appear to indicate a 1MB FLASH, so I am wondering why READ & WRITE to the FLASH is working normally even in areas exceeding 1MB

Thanks

BR

Mr.shim 

[Ozone · Accepted solution]

I don't know the STM32H74x lineup in particular, but this is not really a new phenomenon.
Like most other vendors, ST produces mostly the silicon variants with larger Flash. Individual ICs were the upper Flash region(s) are defective can still be sold as 'smaller' devices.

Trying to employ this extra Flash you will surely run into problems eventually.

[Peter BENSCH]

@hongjo In addition to the statement by @Ozone, you can also take a look at this statement, for example.

Regards
/Peter

[hongjo]

Dear OZone 

thanks for your reply 

[hongjo]

Dear Peter

thanks for your reply 

[STOne-32]

Dear @hongjo ,

As said by @Peter BENSCH  @Ozone , this behavior is normal on this product where the silicon device has 2MBytes of Flash , but only 1 MBytes ( your ordered  part) is fully tested at our factory,  the upper part of the flash we cannot support in case of failure or claim.

Hope it helps you

Cheers,

STOne-32.