Tektronix TDSUSB2 User Manual

TDSUSB2 Universal Serial Bus Measurement Package 077-0015-03

This document supports software version 3.0.3 and above.

www.tektronix.com

Tektronix products are covered by U.S. and foreign patents, issued and pending. Information in this publication supercedes that in all previously published material. Specifications and price change privileges reserved.

TEKTRONIX and TEK are registered trademarks of Tektronix, Inc. TDSUSB2 Compliance Test Software Online Help, 077-0015-03, Version 3.0.6.

Contacting Tektronix: Tektronix, Inc.

14200 SW Karl Braun Drive or P.O. Box 500 Beaverton, OR 97077 USA

For product information, sales, service, and technical support:

• In North America, call 1-800-833-9200.

• Worldwide, visit www.tektronix.com to find contacts in your area.

Table of Contents

General Safety Summary................................................................xi

Introduction .................................................................................... 1

Welcome to the TDSUSB2 Universal Serial Bus Measurements Package .....1

Online Help and Related Documentation........................................................2

Using Online Help...........................................................................................2

Printing from the Online Help.........................................................................4

Conventions.....................................................................................................4

Related Documentation....................................................................................5

Feedback..........................................................................................................6

General information ..................................................................................6

Application specific information...............................................................6

Getting Started................................................................................ 7

Introduction and Product Description..............................................................7

Compatibility...................................................................................................8

Requirements and Restrictions ........................................................................8

Accessories ......................................................................................................8

Optional Accessories.................................................................................8

Installation .................................................................................. 11

Setting up the Instrument to Take Measurements..........................................11

Recommended Instruments and Probes.........................................................11

Installing the Application...............................................................................11

Deskewing .....................................................................................................12

Deskewing the Probes and Channels.......................................................12

Deskewing Probes and Channels on the supported Instruments.............12

Operating Basics...........................................................................19

About Basic Operations................................................................................. 19

Application Interface .....................................................................................19

Application Interface Menu Controls ............................................................19

Basic Instrument Functions ...........................................................................20

Using Basic Oscilloscope Functions.......................................................20

Minimizing and Maximizing the Application.........................................20

TDSUSB2 Universal Serial Bus Measurement Package

Table of Contents

Application Directories and File Names.................................................21

File Name Extensions..............................................................................21

Returning to the Application...................................................................21

Exiting the Application ...........................................................................22

Setting up the Software to take Measurements..............................................22

Description of the Test Fixture................................................................22

Setting Up the Device Details.................................................................23

Setting up the Software...........................................................................24

Setting Preferences..................................................................................24

Table of Measurements and Options .............................................................27

Low Speed and Full Speed Measurements.............................................. 27

High Speed Measurements......................................................................27

Selecting a Measurement...............................................................................28

Signal Quality Check.....................................................................................29

Inrush Current Check.....................................................................................30

Droop Measurement ......................................................................................30

Receiver Sensitivity Measurement ................................................................31

Chirp Measurement........................................................................................33

Monotonic Property.......................................................................................34

Configuring a Measurement ..........................................................................34

Configure Limits............................................................................................35

Configuring Signal Quality Measurements ...................................................35

Configuring Inrush Current Measurements ...................................................36

Configuring Droop Measurements ................................................................36

Configuring Receiver Sensitivity Measurements ..........................................37

Configuring Chirp Measurement...................................................................37

Configuring Reset from High Speed Measurement.......................................39

Configuring Resume Measurement ...............................................................40

Configuring Suspend Measurement...............................................................41

Configuring Reset from Suspend Measurement............................................42

Configuring Packet Parameter Measurement ................................................43

Packet Parameter Measurement.....................................................................44

Suspend Measurement...................................................................................45

TDSUSB2 Universal Serial Bus Measurement Package

Resume Measurement....................................................................................45

Reset from Suspend Measurement.................................................................46

Reset from High Speed Measurement ...........................................................48

Taking Measurements................................................................... 49

Acquiring Data...............................................................................................49

Control Menu Options...................................................................................51

Viewing Results.............................................................................................51

Eye Diagram............................................................................................52

Waveform Plot........................................................................................54

Report Generation..........................................................................................57

Generating Reports..................................................................................57

Viewing Reports......................................................................................58

TSV File Generator.................................................................................58

Table of Contents

TSV file format description.....................................................................59

CSV file format description ....................................................................59

Saving and Recalling Setups..........................................................................60

How to Save and Recall a Setup .............................................................60

Saving a Setup.........................................................................................60

Recalling a Saved Setup..........................................................................60

Recalling the Default Setup..................................................................... 61

Recently Saved Setup..............................................................................61

Recently Recalled Setup..........................................................................61

Tutorial .................................................................................. 63

Introduction to the Tutorial............................................................................63

Starting the Application.................................................................................63

Recalling a .tsv File .......................................................................................63

Taking a Full Speed Signal Quality Measurement........................................64

Taking a Low Speed Inrush Current Measurement.......................................67

Taking a High Speed Signal Quality Measurement.......................................69

Taking a Low Speed Signal Quality Measurement .......................................72

Application Examples....................................................................77

Full Speed Signal Quality Tests for Downstream Testing.............................77

TDSUSB2 Universal Serial Bus Measurement Package

iii

Table of Contents

Specifying the Equipment-Full Speed Signal Quality

Downstream Tests...................................................................................77

Typical Equipment Setup-Full Speed Signal Quality

Downstream Tests...................................................................................77

Selecting and Configuring Measurements-Full Speed Signal

Quality Tests ..........................................................................................78

Configuring the Measurement.................................................................79

Viewing Results-Full Speed Signal Quality Tests ..................................80

Generating Reports-Full Speed Signal Quality Tests..............................81

Droop Test for Ports of Hub..........................................................................82

Specifying the Equipment-Low Speed Droop Tests...............................82

Typical Equipment Setup-Low Speed Droop Tests................................82

Selecting and Configuring Measurements-Droop Tests..........................84

Configuring the Measurement.................................................................84

Viewing Results-Droop Tests .................................................................84

Generating Reports-Droop Tests.............................................................85

Full Speed Signal Quality Tests for Upstream Testing..................................86

Specifying the Equipment-Full Speed Signal Quality Tests for

Upstream Testing ....................................................................................86

Typical Equipment Setup-Full Speed Signal Quality Tests for

Upstream Testing ....................................................................................86

Selecting and Configuring Measurements-Full Speed Signal

Quality Tests for Upstream Testing ........................................................87

Configuring the Measurement.................................................................88

Viewing Results-Full Speed Signal Quality Tests for

Upstream Testing ....................................................................................90

Generating Reports-Full Speed Signal Quality Tests for

Upstream Testing ...................................................................................91

Inrush Current Test for a Device ...................................................................91

Specifying the Equipment-Full Speed Inrush Current Test ....................91

Typical Equipment Setup-Inrush Current Test........................................91

Selecting and Configuring Measurements-Inrush Current Test..............93

Configuring the Measurement.................................................................93

TDSUSB2 Universal Serial Bus Measurement Package

Viewing Results-Inrush Current Test......................................................93

Generating Reports-Inrush Current Test.................................................94

Signal Quality Tests for High Speed Devices................................................95

Specifying the Equipment-Signal Quality Tests for High Speed

Devices for Upstream Testing.................................................................95

Typical Equipment Setup-Signal Quality Tests for High Speed

Devices for Upstream Testing.................................................................95

Selecting and Configuring Measurements-Signal Quality Tests for

High Speed Devices for Upstream Testing.............................................96

Configuring the Measurement.................................................................97

Viewing Results-Signal Quality Tests for High Speed Devices for

Upstream Testing ....................................................................................97

Generating Reports-Signal Quality Tests for High Speed Devices for

Table of Contents

Upstream Testing ..................................................................................100

Packet Parameter Measurement...................................................................101

Specifying the Equipment-Packet Parameter Measurement .................101

Typical Equipment Setup-Packet Parameter Measurement..................101

Set up the Oscilloscope for High Speed Host .......................................101

Selecting and Configuring Measurement-Packet Parameter

Measurement.........................................................................................111

Configuring the Measurement...............................................................112

Viewing Results-Packet Parameter Measurement.................................112

Generating Reports-Packet Parameter Measurement............................113

Resume Measurement..................................................................................115

Specifying the Equipment-Resume Measurement ................................115

Typical Equipment Setup-Resume Measurement.................................116

Selecting and Configuring Measurement-Resume................................117

Configuring the Measurement...............................................................117

Viewing Results-Resume Measurement ...............................................118

Generating Reports-Resume Measurement...........................................118

Reset from Suspend Measurement...............................................................121

Specifying the Equipment-Reset from Suspend Measurement.............121

Typical Equipment Setup-Reset from Suspend Measurement..............121

TDSUSB2 Universal Serial Bus Measurement Package

Table of Contents

Selecting and Configuring Measurement-Reset from Suspend

Measurement........................................................................................122

Configuring the Measurement...............................................................123

Viewing Results-Reset from Suspend Measurement ............................123

Generating Reports-Reset from Suspend Measurement........................124

Suspend Measurement.................................................................................126

Specifying the Equipment-Suspend Measurement................................126

Typical Equipment Setup-Suspend Measurement.................................127

Selecting and Configuring Measurement-Suspend Measurement ........128

Configuring the Measurement...............................................................128

Viewing Results-Suspend Measurement...............................................129

Generating Reports-Suspend Measurement..........................................130

Reset from High Speed Measurement .........................................................132

Specifying the Equipment-Reset from High Speed Measurement........132

Typical Equipment Setup-Reset from High Speed Measurement.........132

Selecting and Configuring Measurement-Reset from High Speed

Measurement.........................................................................................133

Configuring the Measurement...............................................................134

Viewing Results-Reset from High Speed Measurement.......................134

Generating Reports-Reset from High Speed Measurement ..................136

Chirp Measurement......................................................................................138

Specifying the Equipment-Chirp...........................................................138

Typical Equipment Setup-Chirp............................................................138

Selecting and Configuring Measurement-Chirp....................................140

Configuring the Measurement...............................................................141

Viewing Results-Chirp..........................................................................141

Generating Reports-Chirp .....................................................................143

R-GPIB Commands .................................................................... 147

About the R-GPIB Program.........................................................................147

R-GPIB Reference Materials.......................................................................147

Introduction to the R-GPIB Commands ......................................................148

Guidelines to R-GPIB Programming...........................................................148

Launching the Application Using R-GPIB..................................................149

TDSUSB2 Universal Serial Bus Measurement Package

Variable: Value Command ..........................................................................150

Variable: Value TDSUSB2 Command Arguments and

Queries- Application....................................................................................150

Variable: Value TDSUSB2 Command Arguments and

Queries- Sequencer......................................................................................150

Variable: Value TDSUSB2 Command Arguments and

Queries- Save/Recall....................................................................................151

Variable: Value TDSUSB2 Command Arguments and

Queries- Report Generation.........................................................................151

Variable: Value TDSUSB2 Command Arguments and Queries- Results...152

Sample Program...........................................................................................156

Reference ................................................................................ 165

Shortcut Keys...............................................................................................165

Table of Contents

USB2.0 Specifications.................................................................................166

Low Speed.............................................................................................166

Full Speed..............................................................................................167

High Speed............................................................................................168

Inrush Current Check ............................................................................168

Droop Test.............................................................................................169

Error Codes and Warnings...........................................................................169

Settings for the supported Instruments ........................................................176

Upstream Setups for Low Speed signals...............................................176

Upstream Setups for Full Speed signals................................................176

Downstream Setups for Low Speed signals..........................................177

Downstream Setups for Full Speed signals...........................................177

Upstream Setup for High Speed signals................................................177

Inrush Setup...........................................................................................177

Droop Setup...........................................................................................178

Chirp Device EL_28, EL_29 EL_31 setup ...........................................178

Chirp Host EL_33, EL_34 setup...........................................................178

Chirp Host EL_35 setup........................................................................178

Suspend Setup.......................................................................................179

Resume Setup........................................................................................179

Reset from High Speed .........................................................................179

TDSUSB2 Universal Serial Bus Measurement Package

vii

Table of Contents

Reset from Suspend...............................................................................179

Packet Parameter...................................................................................180

Parameters ................................................................................ 181

About Application Parameters.....................................................................181

File Menu Parameters..................................................................................181

Save and Recall Menu Parameters...............................................................181

Preferences Parameters................................................................................181

Measurement Menus....................................................................................182

Measurement Parameters.............................................................................182

Configure Menu...........................................................................................183

Configure Signal Quality Measurements Parameters..................................183

Configure...............................................................................................183

Source....................................................................................................184

Configure Inrush Current Measurement Parameters ...................................184

Configure...............................................................................................184

Source....................................................................................................184

Configure Droop Test Parameters ...............................................................185

Configure...............................................................................................185

Source....................................................................................................185

Configure Receiver Sensitivity....................................................................185

Configure Suspend, Reset from High Speed, Resume, Reset

from Suspend...............................................................................................185

Configure Packet Parameter ........................................................................186

Configure Chirp...........................................................................................186

Results Menus..............................................................................................186

Utilities Menus.............................................................................................187

Deskew ........................................................................................................187

Report Generator Menu Parameters.............................................................187

TSV File Generator Menu Parameters.........................................................188

viii

Help Menu ...................................................................................................188

Control Menu...............................................................................................188

Control Menu Parameters......................................................................188

TDSUSB2 Universal Serial Bus Measurement Package

Measurement Algorithms............................................................ 189

About Measurement Algorithms .................................................................189

Cross-Over Voltage for Low Speed and Full Speed Signals....................... 189

Cross-Over Voltage for High-Speed Signals...............................................191

Signal Rate...................................................................................................192

EOP Width Calculation ...............................................................................193

Consecutive and Paired Jitter.......................................................................194

Eye Diagram................................................................................................195

Eye Violation...............................................................................................195

Inrush Current..............................................................................................196

Droop Test ...................................................................................................196

Receiver Sensitivity Test .............................................................................197

Chirp Test for a Device................................................................................197

Table of Contents

Host Chirp Test............................................................................................198

Monotonic Property Test.............................................................................198

Rise Time.....................................................................................................199

Fall Time......................................................................................................199

Packet Parameter..........................................................................................200

Resume ........................................................................................................201

Suspend........................................................................................................201

Reset from Suspend.....................................................................................202

Reset from High Speed................................................................................203

Equipment Setup for Tests...........................................................................204

Low Speed Downstream Signal Quality Host Equipment Setup..........204

Low Speed Signal Quality for HUB Downstream................................205

Full Speed Signal Quality HUB Downstream Setup.............................206

Full Speed Downstream Host Equipment Setup...................................208

Full Speed Upstream Signal Quality Setup...........................................209

High Speed Device Signal Quality Setup..............................................211

Chirp Test Equipment Setup.................................................................212

Receiver Sensitivity Setup ....................................................................214

Procedural steps.....................................................................................215

Resume Test Equipment Setup..............................................................218

Reset from Suspend Test Equipment Setup..........................................219

TDSUSB2 Universal Serial Bus Measurement Package

Table of Contents

Suspend Test Equipment Setup.............................................................220

Reset from High Speed Test Equipment Setup.....................................221

Packet Parameter Test Equipment Setup.....................................................222

Test Fixture Setup .................................................................................222

Set up the Oscilloscope for High Speed Host .......................................223

Glossary ................................................................................ 233

TDSUSB2 Universal Serial Bus Measurement Package

General Safety Summary

Review the following safety precautions to avoid injury and prevent damage to this product or any products connected to it. To avoid potential hazards, use this product only as specified.

Only qualified personnel should perform service procedures. While using this product, you may need to access other parts of the system. Read

the General Safety Summary in other system manuals for warnings and cautions related to operating the system. To Avoid Fire or Personal Injury:

Connect and Disconnect Properly: Do not connect or disconnect probes or test leads while they are connected to a voltage source.

Observe All Terminal Ratings: To avoid fire or shock hazard, observe all ratings and markings on the product. Consult the product manual for further ratings information before making connections to the product.

Do Not Operate With Suspected Failures: If you suspect there is damage to this product, have it inspected by qualified service personnel.

Symbols and Terms: The following terms and symbols may appear in the online help.

WARNING: Warning statements identify conditions or practices that could

result in injury or loss of life.

: CAUTION: Caution statements identify conditions or practices that could

result in damage to this product or other property.

Terms on the Product: The following terms may appear on the product:

 DANGER indicates an injury hazard immediately accessible as you read the

marking.

 WARNING indicates an injury hazard not immediately accessible as you

read the marking.

 CAUTION indicates a hazard to property including the product.

TDSUSB2 Universal Serial Bus Measurement Package

General Safety Summary

Symbols on the Product: The following symbol (s) may appear in the product:

CAUTION Refer to Help

xii

TDSUSB2 Universal Serial Bus Measurement Package

Introduction

Welcome to the TDSUSB2 Universal Serial Bus Measurements Package

TDSUSB2 Universal Serial Bus Measurements Package is a Sun Java-based application that runs on the supported instruments connected to a PC. You can use the application software with the compliance test fixture to take the following measurements:

 Signal Quality  Inrush  Droop  Drop (supported by the test fixture only)  Receiver Sensitivity  Impedance Measurement using Time Domain Reflectometry (TDR),

supported by the application only with the test fixture

 Chirp measurements  Packet Parameter  Resume  Reset from Suspend  Reset from High Speed  Suspend

TDSUSB2 Universal Serial Bus Measurement Package

Introduction

The application runs on the oscilloscope and displays on the lower part of the screen. The oscilloscope application runs on the upper part of the screen.

Online Help and Related Documentation

You can access the information on how to operate the application and the oscilloscope through the following related documents and online help.

Click Start > Programs > TekApplications > TDSUSB2 > Help to access the Online Help.

Click Start > Programs > TekApplications > TDSUSB2 > Help (PDF Version) to access the PDF version of the Online Help.

Using Online Help

Online help has many advantages over a printed manual because of advanced search capabilities. Select Help on the right side of the application menu bar to bring up the help file.

The main (opening) Help screen shows a series of book icons and three tabs along the top menu, each of which offers a unique mode of assistance:

 Tables of Contents (TOC) tab -organizes the Help into book-like sections.

Select a book icon to open a section; select any of the topics listed under the book.

 Index tab - enables you to scroll a list of alphabetical keywords. Select the

topic of interest to bring up the appropriate help page.

 Search tab - allows a text-based search. Follow these steps:

1. Type the word or phrase you want to find in the search box

2. Select some matching words in the next box to narrow your search

3. Choose a topic in the lower box, and then select the Display button

 To print a topic, select the Print button from the Help Topics menu bar.  Select Options from the menu bar for other commands, such as

Refresh.

 Select the Back button to return to the previous help window. Use the

Hyperlink to jump from one topic to another. If the Back button is grayed out or a jump is not available, choose the Help Topics button to return to the originating help folder.

TDSUSB2 Universal Serial Bus Measurement Package

Introduction

 Browse buttons (Next >> and Previous <<) allow you to move forward

and backward through topics in the order of the Table of Contents (TOC).

 Sometimes you will see the word, Note, in the topic text. This indicates

important information.

 Certain aspects of the online help are unique to applications that run on

the oscilloscope.

Note: Green-underlined text indicates a jump (hyperlink) to another topic. Select the green text to jump to the related topic. For example, select the green text to jump to the topic on button to return to this topic page.

You can tell when the cursor is over an active hyperlink (button, jump, or

popup), because the cursor arrow changes to a small hand.

Online Help and Related Documentation and the Back

Note: The light bulb and the word Tip in the graphic indicates additional information to help you function faster or more efficiently.

. This graphic

TDSUSB2 Universal Serial Bus Measurement Package

Introduction

Printing from the Online Help

Some online help topics have color in the examples of the displayed application. If you want to print this type of topic on a monochrome printer, some information may not print because of certain colors. Instead, you should print the topic from the PDF (portable document format) file that corresponds to the Online Help. You can find the file in the Documents directory on the Optional Applications Software on Windows-Based Oscilloscopes CD–ROM. The figures of application menus in the PDF file are gray scale and all of the information prints.

Conventions

Online help uses the following conventions:

 Refers to the software part of the TDSUSB2 Universal Serial Bus

Measurements Package as the TDSUSB2 application or as the application

 When steps require a sequence of selections using the application interface,

the ">" delimiter marks each transition between a menu and an option. For example, one of the steps to recall a setup file would appear as File> Recall

 Unit under test (UUT) refers to the USB2.0 device under test, hub under

test, host under test, and port under test

 SOF refers to the Start of Frames exchanged between the host controller and

the device when the device is connected to the host and enumerated by the test mode software

TDSUSB2 Universal Serial Bus Measurement Package

Feedback

Tektronix values your feedback on our products. To help us serve you better, please send us your suggestions, ideas, or comments about your oscilloscope.

Direct your feedback via email to 627-5695 and include the following information. Please be as specific as possible.

General information

techsupport@tektronix.com or FAX at (503)

 Instrument model number and hardware options, if any  Probes used  Your name, company, mailing address, phone number, FAX number  Please indicate if you would like to be contacted by Tektronix about your

suggestion or comments

Application specific information

 Software version number  Description of the problem such that technical support can duplicate the

problem

 If possible, save the oscilloscope and application setup files as .set files

 If possible, save the waveform on which you are performing the

measurement as a .wfm file

Once you have gathered this information, you can contact technical support by phone or through e-mail. If using e-mail, be sure to enter in the subject line "TDSUSB2 Problem," and attach the .set and .wfm files.

To include screen shots from the oscilloscope menu bar, select File> Export Setup> Image tab or File > Save > Screen Capture. Save the screen shot in the default directory or you can choose a directory of your choice. If you want the screen shots in color, select Edit> Copy setup> Images tab or select File > Save > Screen Capture and select Options to get the Screen Capture Save Option dialog box. Select the Color, Full Screen and the Normal option buttons. Select Copy. Copy the picture to any Paint editor software.

You can then attach the file to your email (depending on the capabilities of your email editor).

TDSUSB2 Universal Serial Bus Measurement Package

Getting Started

Introduction and Product Description

The TDSUSB2 Universal Serial Bus Measurements is a package that runs on the supported instruments. The solution consists of a Java-based application and a comprehensive test fixture. You can use the application software with the compliance test fixture to take the following measurements:

 Signal Quality  Inrush  Droop  Drop (supported by the test fixture only)  Receiver Sensitivity  Impedance Measurement using Time Domain Reflectometry (TDR),

supported by the application only with the test fixture

 Chirp measurements  Packet Parameter  Resume  Reset from Suspend  Reset from High Speed  Suspend

The application performs tests that measure the test signals for USB2.0 compliance, displays eye diagrams and plots, displays the results as a summary or as details, and generates reports in different formats.

TDSUSB2 Universal Serial Bus Measurement Package

Getting Started

Compatibility

For information on oscilloscope compatibility, refer to the *Optional Applications Software on Windows-Based Oscilloscopes Installation Manual,

Tektronix part number 071-1888-XX. The manual is also available as a PDF file. The dynamic range of the probes used for Low Speed and Full Speed testing should be at least ± 8 volts. For High Speed testing, the dynamic range should be ± 2 volts.

*For a current list of compatible instruments, see the Software and Drivers category in the Tektronix Web site

Requirements and Restrictions

You must install Java Run-Time Environment V1.4.2_02 on the supported oscilloscope.

Accessories

The application uses the Math1 channel for Low Speed and Full Speed mode of operation. You will lose any information that you have stored in the Math1 channel.

You cannot restore the oscilloscope settings if you select File> Exit from the application.

The application includes the following standard accessories:

 Optional Application Software on Windows-Based Instruments CD–ROM  Optional Application Software on Windows-Based Instruments Installation

Manual

 TDSUSB2 Universal Serial Bus Measurements Package Reference  TDSUSBF USB2.0 Compliance Test Fixture Instructions  TDSUSBF USB2.0 Compliance Test Fixture

Optional Accessories

 DG2040 Data Generator (for receiver sensitivity)  AWG610 Arbitrary Waveform Generator  P6248 Differential probes

TDSUSB2 Universal Serial Bus Measurement Package

Getting Started

 P6245, P6243, TAP1500 Single-ended active probes  TCP202/TCP0030 Current probes  TDS8000 Instrument with 80E04 Time Domain Reflectometry sampling

module

 Deskew Fixture: for supported instrument-Probe Calibration and Deskew

Fixture, Tektronix part number (067-0405-xx)

TDSUSB2 Universal Serial Bus Measurement Package

Getting Started

TDSUSB2 Universal Serial Bus Measurement Package

Installation

Setting up the Instrument to Take Measurements

To set up the oscilloscope, follow these steps:

1. You must power on the oscilloscope for twenty minutes before you can start

to take measurements.

2. You must run the compensation signal path on the oscilloscope.

3. You must make sure that the default factory setup is recalled before you

start using the application in the oscilloscope. To do so, push the recall default setup button on the front-panel of the oscilloscope to recall the default factory settings.

4. You should always use calibrated probes and degauss the current probes.

Recommended Instruments and Probes

For information on recommended instruments and probes, refer to the Optional Application Software on Windows-Based Oscilloscopes Installation Manual.

Installing the Application

Refer to the Optional Applications Software on Windows-Based Instruments Installation Manual for the following information:

 Installing an application  Applying a new label  Enabling an application  Downloading updates from the Tektronix Web site

You can find a PDF (portable document format) file of this document in the Documents directory on the Optional Applications Software on Windows-Based Instruments CD–ROM. The CD booklet only contains information on installing the application from the CD and on how to apply a new label.

TDSUSB2 Universal Serial Bus Measurement Package

Installation

Deskewing

Deskewing the Probes and Channels

To ensure accurate measurements, you must deskew the probes before you take measurements from your unit under test. The deskew process is where the oscilloscope adjusts the relative delay between the signals to accurately time correlate the displayed waveforms.

The application includes an automated deskew utility that you can use to deskew any pair of oscilloscope channels.

Note 1: It is recommended that you use the deskew fixture specified in the accessories section to perform deskew. The deskew source can be the built-in probe compensation signal in the oscilloscope or an external signal source. Note 2: The oscilloscope has a deskew range of 50 ns.

Deskewing Probes and Channels on the supported Instruments

To deskew probes and channels on the supported instruments, follow these steps:

1. Connect the probes to Ch1 and Ch2 on the oscilloscope.

2. Connect the probe compensation signal to the deskew fixture. You can use

the probe compensation signal from the oscilloscope as the source for the deskew fixture.

3. Follow the on-screen prompts for the deskew operation with an external

source.

TDSUSB2 Universal Serial Bus Measurement Package

Installation

The following figure shows signals before performing the deskew procedure with a single edge:

Figure 1: Signals before deskew

4. To start the application from a supported oscilloscope, select File> Run

Application> USB2.0 Test Package or Analyze>USB2.0 Test Package from the menu bar of the oscilloscope.

5. Select Utilities> Deskew.

6. Set the channel Source in the From area to Ch1. The Source waveform is the

reference point to which the remaining channels are deskewed.

7. Set the channel Source in the To area to Ch2, to deskew the channel.

8. Select the Reference Level for Ch1 and set the reference value. The

reference level is the percentage level of the waveform from which to take the edges to deskew.

9. Select the Reference Level in the To area for Ch2 and set the reference

value.

10. Select the Hysteresis in the From area for Ch1. Hysteresis helps to ignore

the noise level in the waveform.

TDSUSB2 Universal Serial Bus Measurement Package

Installation

11. Select the Hysteresis in the To area for Ch2 and set the hysteresis value.

12. Select the Slope, Rise or Fall, on which to perform the deskew operation.

13. Select the number of edges used for deskew.

14. To start the deskew utility, select Utilities> Perform Deskew and confirm

the operation.

15. Without changing the From: Ch1 channel, deskew the remaining channels. The following figure shows the results after performing the deskew operation

with a single edge. The reference level is set to 50% for Ch1 and Ch2, the hysteresis is set to 5%, the number of edges is set to 1, and the slope is set to the rising edge.

Note: The probe compensation signals vary from 0.8 to 1 volt (for all supported TDS instruments) and from 0.35 to 1 volt (for all supported DPO instruments) rather than swinging from 0 to 1 volt in a traditional oscilloscope. Set the Reference level and the Hysteresis level appropriately so that the Ref level is at the middle of the swing on the signal.

Figure 2: Signals after deskew

TDSUSB2 Universal Serial Bus Measurement Package

Installation

To perform the deskew operation with an external source, follow these steps:

1. Connect the probes to Ch1 and Ch2 on the oscilloscope.

2. Connect an external source to the deskew fixture.

3. Follow the instructions of the Probe Calibration and Deskew fixture

(Tektronix part number: 067-0405-xx) to make the connections.

4. Set up the oscilloscope as follows:

 Use the Horizontal Scale knob to set the oscilloscope to an acquisition

rate so that there are two or more samples on the deskew edge.

 Use the Vertical Scale and Position knobs to adjust the signals to fill

the display without missing any part of the signals.

 Set the Record Length so that there are more samples for the edges in

the acquisition. It is recommended that you set the record length to 25000 points.

5. To start the application from a supported oscilloscope, select File> Run

Application> USB2.0 Test Package or Analyze> USB2.0 Test Package from the menu bar of the oscilloscope.

6. Select Utilities> Deskew.

7. Set the channel Source in the From area to Ch1. The remaining channels are

deskewed to the Source waveform, which is the reference point.

8. Set the channel Source in the To area to Ch2, the channel to be deskewed.

9. Select the Reference Level for Ch1. The reference level is the percentage

level of the waveform from which to take the edges to deskew.

10. Select the Reference Level in the To area for Ch2 and set the reference

value.

11. Select the Hysteresis in the From area for Ch1. Hysteresis helps to ignore

the noise level in the waveform.

12. Select the Hysteresis in the To area for Ch2 and set the hysteresis value.

13. Select the Slope, Rise or Fall, on which to perform the deskew operation.

14. Select the number of edges used for deskew.

15. To start the deskew utility, select Utilities> Perform Deskew and confirm

the operation.

16. Without changing the From: Ch1 channel, deskew the remaining channels.

17. The setup is an acquisition of a square signal at 100 KHz, with the Record

length set to 25000 points to achieve the sample resolution of 1.6 ns.

TDSUSB2 Universal Serial Bus Measurement Package

Installation

The following figure shows an example of a deskew setup:

Figure 3: Example of deskew setup

18. Set the Reference levels for Ch1 and Ch2 in the application to 50%, the

hysteresis to 10%, the number of edges to 4, and the type to rising edge. The following figure shows the display after performing the deskew for the multiple edge:

TDSUSB2 Universal Serial Bus Measurement Package

+ 220 hidden pages

Tektronix TDSUSB2 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

General Safety Summary

Introduction

Welcome to the TDSUSB2 Universal Serial Bus Measurements Package

Online Help and Related Documentation

Using Online Help

Printing from the Online Help

Conventions

Related Documentation

Feedback

General information

Application specific information

Getting Started

Introduction and Product Description

Compatibility

Requirements and Restrictions

Accessories

Optional Accessories

Installation

Setting up the Instrument to Take Measurements

Recommended Instruments and Probes

Installing the Application

Deskewing

Deskewing the Probes and Channels

Deskewing Probes and Channels on the supported Instruments