How to erase pages on bank 2 on stm32g4?

[Rafael Bachmann]

I was trying to erase some flash pages on an stm32g474re nucleo (and on a custom board with the stm32g474veh3).

The flash pages are all on flash bank 2, because i read in the reference manual that flash bank 2 can be written while code is running from bank 1.

However, erasing pages in the second bank (by setting 'Banks' of the FLASH_EraseInitTypeDef to FLASH_BANK_2) has no effect.

In the example given in https://www.st.com/en/embedded-software/stm32cubeg4.html, (STM32Cube_FW_G4_V1.1.0/Projects/NUCLEO-G474RE/Examples/FLASH/FLASH_EraseProgram), there is a function defined called

uint32_t GetBank(uint32_t Addr)

which just returns FLASH_BANK_1.

This does not make sense to me, isn't flash bank 2 the one bank where erasing or writing makes sense?

Greetings,

Rafael

[TDK · Accepted solution]

The flash in the STM32G4 can be run in either single bank or dual bank mode. (Because why not make it as confusing as possible?)

Is your FLASH_OPTR_DBANK macro defined to enable dual bank mode?

The example you're pointing to runs in single bank mode, so all memory is bank 1.

[Rafael Bachmann]

This is true, but my issue was different.

This app note has a typo:

https://www.st.com/content/ccc/resource/training/technical/product_training/group0/33/dc/74/43/0e/2d/46/4b/STM32G4-Memory-Flash_FLASH/files/STM32G4-Memory-Flash_FLASH.pdf/jcr:content/translations/en.STM32G4-Memory-Flash_FLASH.pdf

It says that the second bank starts at 0x08004000 which is, well, ludicrous =)

[Imen.D]

Hello @Community member​ ,

You are right, the second bank in the STM32G4-Flash presentation is typo mistake.

In RM0440 is correct and it should be 0x0804 0000 - 0x0804 07FF.

I will raise this internally for correction.

Best Regards,

Imen

[Anguel]

Just noticed that you also got it wrong in the Youtube video of the presentation...

[Anguel]

Hmm, are you sure that this example really uses single bank mode? Because dual bank is the default and the example also defines pages as 2 KB, not 4 KB as in single bank mode.

So did they maybe just implement the GetBank() incorrectly?

Best regards,

Anguel

[RBach.1]

For what its worth, see here: https://github.com/barafael/g4-dual-bank-example