MII interface recommended for IEEE 1588 on Vybrid if best jitter performance required

[RossMcLuckie]

If attempting to use IEEE 1588 Timestamping it is important to understand the implications when selecting the Ethernet interface, either RMII or MII.

Using RMII will result in a jitter performance in the region of +/-120 nsecs, this is an inherent function of the RMII interface, when using MII the jitter performance will be in the region of +/-40 nsecs.

As a result it is recommended to use the MII interface if planning to implement IEEE 1588 Timestamping on Vybrid, unless the degraded performance from using the RMII interface is acceptable to your application.

Regards

Ross

[naoumgitnik]

Thanks Ross.

I would not call it jitter but rather latency. If agree, may you correct your original message, please?

BTW, details can be found here - Re: IEEE1588 time-stamping issue, dated "Jan 17, 2014 1:02 PM".

There is also a newly discovered erratum (still in progress) related to this feature (also in that thread).

/Naoum.