i210-IS SERDES Specification

[LukeK]

So we are using the SGMII version of the WGI210 device in a specific way 
to receive data.

We connect a Marvell 88Q2112 PHY, via a TI MUX and a TI CML buffer to 
the WGI210IS Serdes inputs.

I have attached a sample schematic of the components involved in this link.

We have discovered that after some time (typically a couple of weeks) 
some of our WGI210 devices seem to break permanently (specifically the 
SERDES receive channel). We know this is broken permanently because we 
have removed the device and placed it on another of our working boards 
and the link still seems to be broken.

Before it breaks, the link works 100%. We have run tests for several 
days over this link at full gigabit bandwidth and 0 packets are lost. 
When the device breaks the I210 will receive no packets typically, but 
we have also seen in some cases that bursts of packets come through but 
they are all reported as errors.

We are assuming that electrically the SERDES receivers are breaking. 
However, the I210 datasheet does not give any indication of how they 
work electrically, only that they are compliant to SGMII interfaces.

We have used this design with other MACs and PHYs with no failures, but 
it seems that the I210 is sensitive to these outputs.

In the schematic I have noted that the design outputs a 550mV peak-peak 
signal, but in an attempt to fix the problem I have reduced the 
amplitude to 360mV to match the I210 outputs. I can only assume that the 
I210 outputs indicate what the I210 needs, but I have no information on 
these inputs. I have been tested this design with 360mV for a few days 
now with now failures, but this doesn't mean it could fail in the future.

So please could you help us with a few questions :

1. What exactly is required electrically by the I210 SERDES receive 
channels?

2. Could you suggest where the problem could be or how we can debug this 
issue?

3. Could you suggest another SGMII buffer that has been used with the 
I210 successfully?

4. Is there something in the design that we can change to fix the issue?

Thank you and regards

[Caguicla_Intel]

Hello LukeK,

Thank you for posting in Intel Ethernet Communities. 

Can you confirm if your inquiry involves design/customization of your own board? If you do, we have a specific who will be best to assist you and we will be glad to move this thread for further assistance. 

Looking forward to your reply. 

Should there be no response from you, I’ll make sure to reach out after 3 business days. 

Best regards,

Crisselle C.

Intel® Customer Support

[LukeK]

Hi Crisselle

Thank you for your response.

Yes, this is for a custom product for my company and we have an NDA in place if that helps.

Hope to hear from you.

Regards

Luke

[Caguicla_Intel]

Hello Luke, 

Thank you for the confirmation. 

Since your query involves custom board, please be informed that this will be best answered by our Embedded Connectivity Support team. We will help you to move this post to the designated team for further assistance. Please feel free to contact us if you need assistance from Ethernet support team.

Have a good day and stay safe!

Best regards,

Crisselle C.

Intel Customer Support

[Jaime_Lizarme]

Hi Luke,

 Thank you for contacting Intel Embedded Community.

 Just a note to let you know that I have sent you some information to your registered email.

 Regards,

Jaime L.

Intel Customer Support Engineer