DP83867IS: Waveform of SGMII

Hello Matsumoto-san 

Why is the reason for the connector there? Can you try removing it as that may be causing the overshoot and undershoot.

Thanks,

Cecilia

Cecilia san

Thank you so much for your reply.

Why is the reason for the connector there?
->I don't know however we assume that it depends on layout.

Finally, we would like to know followings;
-There is no the setting of register to prevent from overshoot and undershoot. Is it correct?
-If you have the wave form of SGMII with EVM, could you show us?  -> We will inform the cutomer correct waveform of SGMII.

Kind regards,

Hirotaka Matsumoto

Matsumoto-san,

I do not believe with have waveforms from our EVM that we can share. However, I will also confirm with my team on if there are no register settings, but most likely there are not to prevent these overshoots or undershoots. 

My guess is that the connector is adding in extra load capacitance 

Thanks,

Cecilia

Cecilia san

Thank you so much for your cooperation!

I will also confirm with my team on if there are no register settings,
->OK, we are waiting for your update.

Kind regards,

Hirotaka Matsumoto

Cecilia san

Thank you so much for your reply!

As far as I know we do not have any register settings for this.
->OK, we got it.

with the undershoot and overshoot are you able to send and receive packets properly? 
->Yes, the customer is able to send and receive packets properly.

What is the issue you are concerned with on these over/undershoot signals?
->They are concerned with the compliance test.
   Actually, they need some margin, so they need more margin from head room.

Kind regards,

Hirotaka Matsumoto

Matsumoto-san 

Can you share the results of the compliance test? How much of a margin do they need? Are they already failing with these results? 

Thanks,

Cecilia

Cecilia san

Thank you so much for your reply!


Can you share the results of the compliance test?
->We could not accept from the customer.

Are they already failing with these results? 
->No, we assume that they could pass it.
   However, if there is the way to reduce overshoot and undershoot, they would like to try it.

Kind regards,

Hirotaka Matsumoto