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RE: XGMII repeater


From my count, this repeater would have 74 pins in each direction, for a
total of about 148 pins.  With the power and ground requirements, the
repeater device would most likely use a 208 pin package.  Going 10 inches on
a server motherboard would require 4 of these repeater devices plus the real
estate for the 76 PCB traces and the device.

I know I'd have a tough time trying to convince my customers that this is a
better solution than XAUI.  For the same implementation, two XGXS devices
and 16 PCB traces to do the same thing is simpler and lower cost.  I know my
customers like things to be simpler and less expensive.


	-----Original Message-----
	From:	Curt Berg [SMTP:cberg@xxxxxxxxxxxxxxxxxxx]
	Sent:	Tuesday, March 21, 2000 10:02 AM
	To:	stds-802-3-hssg@xxxxxxxx
	Subject:	XGMII repeater

	XGMII is basically source synchronous,
	(don't know how the pacing will be done).
	To me this means an inexpensive extender/repeater 
	chip can easily be built.

	If we use an HSTL, or impedance controlled
	driver for XGMII, it should be possible to extend
	the bus with several hops, and even through connectors.
	At these baud rates (312.5M) it might even be possible to 
	retime the data without PLLs.

	My conclusion is that physical distance on XGMII should not
	be a big issue. 

	-Curt Berg-
	Extreme Networks