Teledyne LeCroy VirtualProbe - Manual (Page 13)

Operator's Manual
is when you wish to understand how a signal would look if the path between the trans-
mitter and receiver were to be extended by an interconnect that does physically exist, and
for which you only have an S-parameter model.
C ONFIGURATION
The Config selector allows the user to from several topologies for the XTalk block:
1xS8P - Select to use a single 8-port S-parameter model
1xS12P - Select to use a single 12-port S-parameter model
2xS8P - Select to use two 8-port S-parameter models.
The dialog will adapt based on the config selected, showing a network(s) with the number of ports cor-
responding to the selection. For example, selecting 1xS12P shows a 12-port network; selecting 2xS8P
shows two 8-port networks (16 ports total).
P ORTS A SSIGNMENTS
On the left side of the Touchstone File Port Mapping section, select the S-parameter port number that
maps to the signal flow for each lane. Lane numbers go from top to bottom, and, since each lane is dif-
ferential in the XTalk model, each lane should map to a (+) and (-) port. On the right side, select the ports
that correspond as THRUs for the input ports.
A PPLY S ETTINGS
After completing XTalk configuration, switch to the VirtualProbe or any VP Setup dialog and click Apply.
The system description is compiled. When XTalk is active, there is only one system description to com-
pile, which includes all lanes.
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