25MHz clock out for RGMII

langerboris — Wed, 18 Jan 2017 14:14:00 GMT

In my RGMII setup i would like to remove the PHY crystal so i'm hoping to generate 25 MHz (instead of 50 MHz for RMII use cases) from GPIO16, route it to the PHY and then route back the 125MHz clock from this to the ENET_REF_CLK. Does this setup work?

If not, are there any other suitable I/Os to generate a 25MHz clock available?

Re: 25MHz clock out for RGMII

gusarambula — Wed, 18 Jan 2017 17:36:36 GMT

Hello Langer Boris,

It is possible to do as you wish, as mentioned on Table 2-9 of the Hardware Development Guide for i.MX6 (link below).

http://www.nxp.com/assets/documents/data/en/user-guides/IMX6DQ6SDLHDG.pdf

You may either generate the 125MHZ but if your PHY requires the 25MHZ you may configure the clock to feed the PHY and then bring the 125MHZ clock to ENET_REF_CLK.

I hope this helps!

Regards,

topic 25MHz clock out for RGMII in i.MX Processors

25MHz clock out for RGMII

Re: 25MHz clock out for RGMII