Operator's Manual VirtualProbe Software
VirtualProbe Software Operator's Manual © 2013 Teledyne LeCroy, Inc. All rights reserved. Unauthorized duplication of Teledyne LeCroy documentation materials other than for internal sales and distribution purposes is strictly prohibited. However, clients are encouraged to distribute and duplicate Teledyne LeCroy documentation for their own internal educational purposes. VirtualProbe and Teledyne LeCroy are registered trademarks of Teledyne LeCroy, Inc.
Operator's Manual TABLE OF CONTENTS Virtual Probe Overview Virtual Probe Process Choose Your Mode of Operation VirtualProbe, EyeDoctor-VP and EyeDoctor II Compatible Models Required Firmware Modeling the Circuit VirtualProbe Main Dialog Setup Dialog Block Setup Dialog VirtualProbe (XTalk) Crosstalk Block Touchstone File Format 921148 Rev A 2 2 3 3 3 3 4 4 6 8 10 12 1
VirtualProbe Software Virtual Probe Overview The Teledyne LeCroy Virtual Probesoftware option lets you view waveforms as they would appear in circuit locations other than the probing point, and in circuit configurations different from the configuration actually used for the measurement. By using Virtual Probe, you can understand the characteristics of signals where a physical probe cannot be placed, such as inside of a package or at the end of an interconnect that doesn't physically exist.
Operator's Manual l l Identify the position of a "virtual probe" that outputs the waveform that would be seen at the selected position . When used in conjunction with SDAIII-CompleteLinQ serial data analysis packages, use the VirtualProbe output as the source waveforms for equalization, eye, jitter, and noise measurements. Choose Your Mode of Operation VirtualProbe appears in the Analysis menu of the scope application.
VirtualProbe Software Modeling the Circuit VirtualProbe Main Dialog The VirtualProbe main dialog is used to select an active setup/lane and configure the "blocks" in the circuit represented by it. It also displays summary information on and under each block that allows you to quickly see how that block in the circuit is defined. Before using this dialog to configure individual blocks, go to the VirtualProbe Setup Dialog to configure the overall setup/lane.
Operator's Manual Status LED - An LED next to the Apply button indicates the status of the VirtualProbe setup for the selected lane. Setup Status LED - An LED next to each setup button displays the current status of the setup. l Red: Error in setup. Check the setup for any inconsistency in the Num Ports, Input Type, or the block setup for undefined files or touchstone files with incorrect port count.
VirtualProbe Software Setup Dialog The Virtual Probe Setup dialog configures the overall settings for the circuit represented by the selected setup or lane. Source Setup The settings in the Source Setup section of the dialog define the overall topology of the circuit and how it connects to the oscilloscope taking the measurement. Num Ports field - Enter 2 or 4 to define whether the circuit is connecting a single-ended or differential lane between the transmitter and receiver.
Operator's Manual NOTE: there is no need to configure a math function to be the difference between two inputs when using VirtualProbe. SDAIII-COMPLETELINQ USE When using VirtualProbe from within the SDAIII-CompleteLinQ framework, the data source for the active lane is configured on the SDAIII-CompleteLinQ Signal dialog. Measurement Filter Section The measurement filter section of the Setup dialog configures elements that determine the bandwidth limit of the filter and the maximum gain.
VirtualProbe Software Block Setup Dialog The Block Setup dialog is displayed when you touch a Block definition button. It is used to configure the corresponding block in the circuit. Block Action Checkboxes When a block is configured for something other than "Ideal Thru," the left-side of the dialog includes a set of checkboxes that determine how the circuit element defined by the block is handled.
Operator's Manual Transmission Line - Select to use a lossless transmission line modeled by its delay and characteristic impedance. Touchstone File - Select to use S-parameters to represent the block. The Touchstone file should follow the Touchstone 1 format, and should also meet requirements described in Touchstone File Format. When you select Touchstone File, the additional settings described below are enabled.
VirtualProbe Software Mapping for two-port network specified in two files. VirtualProbe (XTalk) Crosstalk Block When the Crosstalk package is present on the oscilloscope, the main VirtualProbe dialog will include the XTalk block. The block is used to define the S-parameter Touchstone file and port assignments. By using the XTalk block—and in doing so, including a model of the crosstalk between lanes—you can create a more accurate model of the circuit and obtain better VirtualProbe results.
Operator's Manual is when you wish to understand how a signal would look if the path between the transmitter and receiver were to be extended by an interconnect that does physically exist, and for which you only have an S-parameter model. CONFIGURATION 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.
VirtualProbe Software Warnings and Error Messages If all lanes are not setup as 4 port, Channel in the VP Setup dialogs for each lane, then a message will be displayed. For example: Warning triangles may also be displayed in the XTalk dialog when an error situation exist. Touch the triangle to call up a dialog that explains the error. Touchstone File Format Touchstone is a file format used for specifying S-parameters.
Operator's Manual l All frequencies are assumed to go from the first frequency listed to the last frequency listed with constant frequency spacing. S-parameter File Interpretation and Usage S-parameters provided to the virtual probe will tend to have various frequency scales, differing in both resolution (frequency spacing) and range (start frequency and end frequency).
