2nd Ethernet KSZ8041 with iMX7d

I use 2nd Ethernet PHY KSZ8041 with iMX7d board in RMII mode and I get some problem to make it work. My first problem is to make the iMX7d board to generate the 50MHz clock for my 2nd PHY. Is there someone to clarify the registry programmation to make it work ? Thank you

Hi @Phil_Elec ,

Although there would be a way to generate the 50 Mhz clock in the SOC (ccm.ENET2_REF_CLK_ROOT see Toradex Colibri iMX7 Datasheet), it’s not recommended to do so, as the generated 50Mhz clock will not be accurate enough for a 100Mbit PHY.

See Errata #7:


The best solution is to use a dedicated 50Mhz Crystal or Oscillator. (That’s also what we do on the module for the internal Phy)