External RMII reference clock on i.mx93 (ENET_QOS)

[YoshiDev]

Hi all, 

We are using ENET1 interface on an i.mx93 SOC in RMII mode. The RMII phy transceiver generates its own 50MHz reference clock. How can we configure this? 

The i.mx8mp has a similar hardware architecture, and has a special register in its GPR where we configure such settings. However the reference manual of the i.mx93 does not mention such registers, but it mentions in section 43.4.2 that it should be possible. 

Kind regards, 

Yoshi

[Manuel_Salas]

Hello @YoshiDev ,

Could you please share more details about the PHY you are using?

and

What is the clock source you want to use (SOC or PHY)?

Best regards!

[YoshiDev · Accepted solution]

Hi, 

Thank you for your reply. 

Both the SOC and the PHY were generating the RMII reference clock. However, we wanted the PHY to generate the reference clock. 

However, I was able to disable the clock generation of the SOC after reading the reference manual again. We overlooked the enet clock direction selection register of the WAKEUPMIX. 

Kind regards, 

Yoshi