How to read/flash WSON8 W25M chip series (w25m02gvzeig)

Thread Starter


Joined Oct 27, 2021
Hi all,

I'm new here, hope to be in the right place. I'm not skilled at all in the hardware stuff, so I'm looking for help in order to figure out how to solve my problem.

Recently I bought a device for photovoltaic monitoring. Unfortunately after the firmware upgrade, the device started rebooting in an infinite loop, I think it's bricked. I can't send back to the vendor the device, so I decided to open it and fix it.

Unfortunately, the device SOC has a Winbond's Flash Memory is packed in a WSON8, furthermore I do not see any programmer or tools (flashrom) that support this chip.

Winbond Nand Flash Memory with SpiStack® Technology by Winbond
ref: revb 070115.pdf

What should I do, do you know other methods?



Joined Sep 17, 2013
The data sheet for the memory part talks about "quad SPI" which is the common technology for SD memory cards (like SDHC). I'm not enough of an expert in the hardware aspects of this technology to know whether a particular device that is designed to program a particular SDHC flash memory can program the Winbond part. However it is certainly possible that an SDHC card that you have a way to program MIGHT be able to be substituted for the Winbond chip in your circuit at least for the read functions, maybe more. It would probably take some research to figure out whether the flash part is hardware compatible at some level. It's also a concern (at least on the surface) that you may need access to some low-level boot routines from your original card to even consider getting the software upgrade programmed onto the card (maybe it gets transfer-loaded into the MCU's RAM and run from there). All difficult issues to consider, and not recommended to be solved by a newbie if you can't afford to lose all the HW that you still have even partly working by making an "inaccurate guess".