10/100Mbit only RMII solution for verdin iMX8M

We need a 10/100Mbit only RMII solution for verdin iMX8M (2nd Ethernet). In the carrier board design guide there is only a Gbit solution, but we would prefer a 10/100MBit only solution, as it is simplier. When searching the community I found the topic " Verdin IMX8MP with LAN8720A on RMII interface" which does not work. So is there any recommendation?

Hi @rosenheim !

I just asked internally about a recommendation.

I will get back to you as soon as I have some information.

In the mean time, could you please share the following information:

  • Which exact Verdin iMX8M Plus are you using? Please share its full name and version.
  • Which OS do you intend to use? Custom made with Yocto? TorizonCore?

Best regards,

Hi Henrique,
we’ll use the Verdin iMX8M Plus Quad 4GB IT (PN: 00631100) board, OS will bei custom made with Yocto.

Hello rosenheim,

if you use the 100 Mbit RMII you have to use pins of the module that are not guaranteed to be available on other verdin SOMs in the future.
RMII signals (alternate functions, not compatible with other Verdin modules) see datasheet page 36 https://docs.toradex.com/110977-verdin_imx8m_plus_v1.1_datasheet.pdf

Best Regards,

Matthias Gohlke

Hello Matthias,
good advice. So I’ll use the RGMII interface. In the KSZ9131RNX Hardware Design Checklist I found the instruction how to use the KSZ9131RNX with 10/100Mbit-only speed.
By the way you make a very good job in carrier board design guidelines.