F_ECATPHY clock generation details

[User15702]

Hello,

Whether anybody could to describe the details of generation of the F_ECATPHY signal. You could give counsel at option of quartz resonator for use in ECAT applications for accuracy and stability.

Thank you
Gene

[MichaelIFX]

I'm not sure if I really understood your question.
However please see our Relax Kit which demonstrates the appliance of the clock.
As demonstrated there, in general the clock from XMC must be provided to the PHY (PHY_CLK25).

We do not recommend single crystals. The external oscillator circuitry must be optimized by the customer and checked for negative resistance and
amplitude as recommended and specified by crystal suppliers.

In general the clock period supplied to the PHY must be of an accuracy of 25ppm.

See also:
https://download.beckhoff.com/download/Document/io/ethercat-development-products/an_esc_faq_v1i2.pdf
3.2 ESC clock source accuracy: Is 25 ppm necessary?

Kind Regards

Michael

[User15702]

Hello Michael,

Thank you for your answer. I will try to formulate question more accurate. I read the XMC 4800 User Manual and I did not find any configuration options for setting F_ECATPHY frequency depending on crystal frequency/pll frequencies used. It appears as if the CCU module does it itself?

Thank you
Gene