STM32H7S7 PSRAM REFERENCE using APS256XXN-OBR-BG

[Hamady]

Hello ,

I'm desining a PCB for the H7S7 and the PSRAM on the discovery board is : APS256XXN-OBR-BG

But it seems to be NRND.

Can you confirm that this chip can be used in remplacement ?

APS256XXN-OBx9

https://www.apmemory.com/en/downloadFiles/0325021716tb786912

Thanks

[KDJEM.1]

Hello @Hamady ;

To check whether a device is supported by the XSPI interface, you need to refer to the device datasheet. Then, check the command format and order shared in the device datasheet must be aligned with the command format and order mentioned in the STM32 reference.

For more XSPI tips and tricks, I recommend you to look at Overall FAQs for QUADSPI/OCTOSPI/HSPI/XSPI - STMicroelectronics Community

Thank you.

Kaouthar

[Alex - APMemory]

Hi, 

Please use APS256XXN-OB9-BG, this is latest device revision (highest speed grade covering all previous) for this PSRAM family and fully compatible with STM32H7S7 without any change, (as well as all other STM32 supporting OPI). See attached some more comment and recommendation.

Thanks

Alex

[Hamady]

Hi @Alex - APMemory 

Thanks for the info 

I'm happy to report that we used APS256XXN-OB9-BG with succes in our custom pcb

Concerning the doc you shared is there any modification to be done in Cube MX

Thanks

[Alex - APMemory]

Good to and thanks for the confirmation using the "OB9" version successfully

you can use the "OBR" & "OB9" version with the same configuration.

The report is advising a second point, which is the recommendation to use the CSBOUND function, rather the  RBX read option (row boundary crossing). if your SW is already done, no need to change, but if not, this is a better habit to take. 

Cross-page access: Method 1: By PSRAM RBX(Row Boundary Crossing) feature if available
Single-page access: Method 2: By controller page-boundary setting if available   => RECOMMENDED