10-26-2011 12:15 AM
I've got a problem with the GTX Transceivers of the LX240T on my ML605 Board.
On the pictures you see two different eye diagrams. One is the output of an Anritsu MP1800A and the other is the output of the ML605 with IBERT Design. Both are 7bit PRBS Signals. The output of the ML605 seems to be very noisy doesn't it? I think there must be some kind of Jitter, but where does it come from? Im sure I've had better eye patterns of the ML605 before. I'm still using the reference design from the usb stick... Can somebody help me?
10-26-2011 08:00 AM
10-27-2011 02:51 AM
Both, ML605 (J26/J27) and Anritsu MP1800A are connected the same way by a matched SMA cable to the Tektronix DSA8200 Digital Serial Analyzer (with differential probe). So there should be no big influence by the link.
Yes you're right i just took the reference IBERT Design from the USB Stick. So today I've customized a new design with the Core Generator with only one active GTX Transceiver. Unfortunately I got nearly the same result (see attachment)...
Is there any other reason for such a noisy signal? I think the eye pattern of a Virtex6 GTX Transceiver should be better, shouldn't it? I am confident with the opening but the jitter unsettles me...
Thank you for your help!
10-27-2011 09:26 AM