EMMC Documentation

[Ecic2002]

Hello,

I am working on integrating a 5.1 EMMc with an NRF52840 running Zephyr. I am looking for some further documentation or a possible example. So far, I have found the following in Zephyr Docs. Thank you.

https://docs.zephyrproject.org/latest/services/storage/disk/access.html

" Zephyr also has support for eMMC devices using the Disk Access API. MMC in zephyr is implemented using the SD subsystem because the MMC bus shares a lot of similarity with the SD bus. MMC controllers also use the SDHC device driver API. "

https://docs.zephyrproject.org/latest/build/dts/api/bindings/sd/zephyr,mmc-disk.html

[Turbo J]

EMMC dropped SPI support around spec 4.5 version (i.e. many years ago).

Check the datasheet of your chip if it still supported that mode, the NRF chips don't support the wider SD or EMMC modes in hardware.

[Ecic2002]

If I understand you correctly, does the Zephyr EMMC support only consider the SPI protocol?

[Joakim Jakobsen]

As far as I can see we do not have any eMMC interfaces. We can support SD/MMC cards over SPI, but SPI support is not supported for eMMC.

There are some previous tickets already on devzone discussing this topic. You might have some luck searching through some of those;
ie: eMMC integration

Br,
Joakim