Hi everyone,
I’m working with an STM32H7S3 microcontroller and an external Octo-SPI NOR flash IS25WX064 from ISSI (datasheet: https://www.issi.com/WW/pdf/25LX-WX032-064.pdf)
My goal is to get this memory working with ExtMemLoader (including XIP support). I’ve gone through all the available tutorials and many of the forum threads related to ISSI 25LX/WX devices, but after many hours I still haven’t been able to generate even a single .stldr that doesn’t crash in the STM32CubeProgrammer.
A few important points:
This does not seem to be a hardware issue. I can successfully communicate with the flash and read the manufacturer configuration/registers via the XSPI peripheral.
I have been following the ST tutorials for this MCU family (the ones that use the Macronix flash on the official demo board).
In my case, when I try to adapt the code for the IS25WX064, the driver fails in the last check of step 9 of the EXTMEM_NOR_SFDP driver (the final verification step):
After a lot of iterations, I would really appreciate some clarification:
Is it actually possible to use the EXTMEM_NOR_SFDP driver with the ISSI IS25WX064, or is this driver incompatible with this flash family?
If it’s supposed to work, are there any known configuration changes needed (e.g. SFDP quirks, different parameter tables, etc.)?If EXTMEM_NOR_SFDP is not suitable for this device, am I expected to write my own custom driver manually (as in the older tutorials for ISSI memories), and add XIP support myself?
For example, based on these resources:
https://community.st.com/t5/stm32-mcus/how-to-set-up-the-ospi-peripheral-to-interface-with-the/ta-p/49474
https://youtu.be/JAlMxgjlSkE
In that case, should I be working in EXTMEM_USER driver?
Is there any documentation or “user manual” that explains in detail how to properly use EXTMEM_USER mode to implement a fully custom driver (including what callbacks are mandatory, how XIP is expected to be set up, etc.)?
Some extra details about the flash configuration: All flash registers are currently left at their default values. After initializing the XSPI peripheral, I send only a reset command to the memory. I have also tried switching the memory to Octal DDR mode, and forcing Memory Mapped Mode by manually programming the registers, but in those cases the initialization fails even before step 9 of the EXTMEM_NOR_SFDP driver. Of course I have set the Memory type to "Micron" in the XSPI configuration.
If anyone has successfully used an ISSI IS25WX064 (or similar 25LX/WX series) with STM32H7S3 and the ExtMemLoader or can confirm whether EXTMEM_NOR_SFDP can support this device, I would be very grateful for any hints, example projects, or configuration guidelines.
Thanks in advance for your help!
