Can I use IS25WX01G flash instead of MX66UW1G45G on STM32N657X0H3Q

[Ajnas-c]

Hi Team,

I'm designing a custom board around the STM32N657X0H3Q and evaluating whether I can replace the reference MX66UW1G45GXDI00 (Macronix, used on the STM32N6570-DK) with the ISSI IS25WX01G-JILE (24-ball LFBGA, 1Gb, 1.7–2.0V Octal DDR NOR flash 166MHZ) as the external boot flash.

My questions:

1. Does the STM32N6 stage-0 (ROM) bootloader have hard-coded protocol/timing parameters tied specifically to the Macronix MX66UW1G45G, or is there a way to configure it for a different vendor/command set (e.g., via OTP, option bytes, or FSBL configuration)?
2. Is JEDEC manufacturer ID checked/enforced anywhere in the boot chain (ROM bootloader, FSBL, or STM32CubeProgrammer external loader) in a way that would reject a non-Macronix part?
3. Has anyone successfully booted an STM32N6 from a non-Macronix Octal DDR/OPI flash (e.g., ISSI, Winbond) by writing a custom BSP/XSPI driver, or is the boot ROM's dependency on the Macronix command set a hard blocker regardless of driver customization?
4. Has the IS25WX01G-JILE been validated or tested by ST with the STM32N6 series?
5. Is there an existing STM32CubeProgrammer external loader (.stldr) or BSP driver available for this ISSI flash device?
6. Can i use Quad flash instead of Octal for external flash? Please guide me how the integration?

Any guidance — official documentation, AN references, or prior experience — would be greatly appreciated.

 

Regards,

Ajnas

[KDJEM.1]

Hello ​@Ajnas-c and welcome to the community;

 

The model of  IS25WX01G is not supported by STM32N6 Cube ecosystem. You could refer to the following release notes files to find the supported memories: STM32Cube_FW_N6_V1.2.0/Middlewares/ST/STM32_ExtMem_Manager/Release_Notes.html

Thank you.

Kaouthar

[Ajnas-c]

Thanks for the details.

As per your response, does this mean that the STM32N6 supports only the flash devices included in the recommended list? If we need to use a different compatible flash device, what changes or additional steps would be required to make it work?

 

Regards,

Ajans C

[KDJEM.1]

Hello  ​@Ajnas-c ;

 

If the memory reference is not listed in supported by STM32N6 Cube ecosystem list you need to check if the memory is supported by the interface or not. So, in order to start, the user must verify if these interfaces are supported by the device. The command format and order shared in the device datasheet must be aligned with the command format and order mentioned in the STM32 reference. Then you need to develop specific drivers for the memory being used.

 

Thank you.

Kaouthar