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Re: 16-bit 625Mbaud XGMII





Jaimie,
I agree with Andy. We've done ASIC designs with the 622MHz OIF interface
and timing is rather tough. The 312M is much easier.





Andreas Bechtolsheim <avb@xxxxxxxxx>@ieee.org on 03/20/2000 04:07:09 PM

Sent by:  owner-stds-802-3-hssg@xxxxxxxx


To:   stds-802-3-hssg@xxxxxxxx, kardontchik.jaime@xxxxxxxxxxx
cc:
Subject:  Re: 16-bit 625Mbaud XGMII




Jaimie: you need to count package pins, not signal I/Os.

Your 625 MHz XGMII using LVDS differential signalling
requires 76 pins, which is the same pincost as the
312.5 MHz XGMII using single-ended drivers.

In addition, you would need to run at least part of
your logic at the 625 MHz which is significantly
more difficult to implement than staying with a
clock frequency of 312.5 MHz.