Flash memory size of STM32H743XGH6

[FlashInquiry_JP]

The STM32H743XGH6 is specified to have 1 MB of Flash memory.
However, it seems that the following 2 MB address ranges are writable:
BANK1: 0x08000000 to 0x080FFFFF
BANK2: 0x08100000 to 0x081FFFFF

If the device really has only 1 MB of Flash, I would expect the usable ranges to be:
BANK1: 0x08000000 to 0x0807FFFF
BANK2: 0x08100000 to 0x0817FFFF
Also, when I executed an erase operation on BANK2, it started erasing from address 0x08100000.

My question is:
Are the following areas valid and safe to use?
BANK1: 0x08080000 to 0x080FFFFF
BANK2: 0x08180000 to 0x081FFFFF

Any clarification about the actual usable Flash memory area would be appreciated.

[TDK · Accepted solution]

Only the 1 MB specified in the datasheet is tested and guaranteed to work. The additional 1 MB may be present but is not tested or guaranteed to function correctly (although most likely it works just fine).

This happens when the same die is used for multiple chips. The additional testing takes time.