NUCLEO-U575ZI-Q memory size incorrect in Arduino IDE showing 256 kbytes should be 786 kbytes

[Captainslarty]

Incorrect dynamic memory size being used by Arduino IDE for board Using NUCLEO-U575ZI-Q
IDE is showing - Maximum as 256 kbytes where device actually has 786 Kbytes of SRAM

Using NUCLEO-U575ZI-Q
Arduino IDE 1.8.19
Core 2.3.0

example report from 'blink' sketch

Sketch uses 19820 bytes (0%) of program storage space. Maximum is 2097152 bytes.
Global variables use 1016 bytes (0%) of dynamic memory, leaving 261128 bytes for local variables. Maximum is 262144 bytes.

thank you
Joe

[fpistm]

Hi @Captainslarty
Thanks to report this.
You're right, this mcu got up to 756Kb.
To define boards we generate several files automatically using the STM32_open_pin_data database. This is the same than the one used by STM32CubeMx tools.
The xml describing the STM32U575ZITxQ give 256Kb ram: https://github.com/STMicroelectronics/STM32_open_pin_data/blob/ae7fb660038b0bd9a2d50f0fa443dc024b15a4c9/mcu/STM32U575ZITxQ.xml#L13

Anyway the STM32CubeMx tools show the correct size. I have to investigate why/how and then probably update our scripts.

As a workaround you can edit the boards.txt and change the value:
https://github.com/stm32duino/Arduino_Core_STM32/blob/main/boards.txt#L200

[Captainslarty]

Hi and thank you for the very prompt response. Much appreciated.
Please can I confirm with you the exact values that should be entered in these two lines ?

Nucleo_144.menu.pnum.NUCLEO_U575ZI_Q.upload.maximum_size=2097152 Nucleo_144.menu.pnum.NUCLEO_U575ZI_Q.upload.maximum_data_size=262144

[fpistm]

here is the ram size entry:
Nucleo_144.menu.pnum.NUCLEO_U575ZI_Q.upload.maximum_data_size=786432

--> (192 + 64 + 512) * 1024

Anyway, I didn't check if you can use all the RAM. There is 4 SRAM + 1 bck SRAM:

That's why I set only SRAM1/SRAM2/SRAM3.

[Captainslarty]

Understood, Thank you.
Joe

[fpistm]

This would be fine to see if all RAM are contiguous else there will be an issue. 😉 In a general way this core simply manage maximum contiguous RAM without ECC for more complex RAM configuration some extra config are required and custom linker script have to be used.

[Captainslarty]

That is really appreciated. Fortunately or unfortunately ;) my level of knowledge is such that I will be highly unlikely to attempt more complex ram configurations :). I have made the changes and all appears well.
I know this next bit is going off topic slightly but please can I just enquire as to how I may get the NUCLEO-H7A3ZI-Q added to the Arduino core ? . I am not knowledgeable enough to produce a variant. Thanks again. Amazing support. Joe

[fpistm]

I think it is OK anyway I would prefer warn you 😉
About the Nucleo H7 it is already in the request variant list: #722
I've reference your comment too.

[Captainslarty]

Thank you ever so much for all your kind help Frederic.
Regards,
Joe

[fpistm]

Hi @Captainslarty

issue confirmed internally and xml files will be corrected. I made a patch to fix them in the core.
About the size, We only set 768K as the SRAM4 is not consecutive:

[Captainslarty]

Thank you again for you very hind help and response. Very much appreciated.
Joe