GD25WB256 Alternative + Firmware Changes (nRF9151 External Flash)

[Akshay]

Hi,

I’m using GD25WB256 as external flash on nRF9151 for MCUboot secondary slot. It’s currently not available from our supplier, so I’m looking for alternatives.

Current overlay:

/ {
    chosen {
        nordic,pm-ext-flash = &gd25wb256;
    };
};

&gd25wb256 {
    status = "okay";
};

Questions:

1. What are good 256Mbit SPI NOR alternatives (preferably 1.8V) that work well with nRF Connect SDK + MCUboot?
   • Considering Winbond / ISSI / Macronix parts
2. For replacing the flash, is it enough to:
   • Just update the device tree (JEDEC ID, size)
   • Keep everything else unchanged?
3. Anything to watch out for (4-byte addressing, SFDP, etc.)?

Thanks!

[Hung Bui]

Hi Akshay, 

We won't be able to give you a specific recommendation for an alternative to GD25WB256. The NCS SDK is highly agnostic to a specific flash chip. Any modern QSPI flash will be "plug-and-play" once you update the JEDEC ID and size in your Devicetree. We are not supposed to give any "favorite" flash chip/ manufacturer that you should use. 

As far as I know, you just need to use the correct JDEC ID and correct size in the device tree overlay you should be fine. 

Anything to watch out for (4-byte addressing, SFDP, etc.)?

Not that I'm aware of, AFAIK you just need enter-4byte-addr = <0x01>;     defined in the device tree overlay.