qphy-sas2 instruction manual - teledyne lecroy

QPHY-SAS2 SAS2 Serial Data Compliance Software

Instruction Manual

Revision B – November, 2017 Relating to:

XStreamDSO™ Version 8.5.x.x and later QualiPHY Version 8.5.x.x and later

700 Chestnut Ridge Road Chestnut Ridge, NY, 10977-6499 Tel: (845) 425-2000, Fax: (845) 578 5985 teledynelecroy.com

© 2017 Teledyne LeCroy, Inc. All rights reserved. Customers are permitted to duplicate and distribute Teledyne LeCroy documentation for internal training purposes. Unauthorized duplication is strictly prohibited. Teledyne LeCroy and other product or brand names are trademarks or requested trademarks of their respective holders. Information in this publication supersedes all earlier versions. Specifications are subject to change without notice. 922262 Rev B November, 2017

QPHY-SAS2 Instruction Manual

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Table of Contents Introduction .................................................................................................................................................. 1 Test Equipment .............................................................................................................................................. 1

Oscilloscope ........................................................................................................................................... 1 Test Fixture and Cables ......................................................................................................................... 2 Protocol Analyzer (Optional) .................................................................................................................. 2

Remote Host Computer Requirements ......................................................................................................... 3 Installation and Setup ................................................................................................................................. 4 Install Base Application .................................................................................................................................. 4 Activate Components..................................................................................................................................... 4 Set Up Dual Monitor Display ......................................................................................................................... 4 Set Up Remote Control ................................................................................................................................. 5

Configure Oscilloscope for Remote Control ........................................................................................... 5 Add Connection to QualiPHY ................................................................................................................. 5 Select Connection .................................................................................................................................. 5

Using QualiPHY ........................................................................................................................................... 6 Accessing the Software ................................................................................................................................. 6 General Setup ................................................................................................................................................ 7

Connection tab ....................................................................................................................................... 7 Session Info tab ...................................................................................................................................... 7 Report tab ............................................................................................................................................... 7 Advanced tab ......................................................................................................................................... 7 About tab ................................................................................................................................................ 7

QualiPHY Test Process ................................................................................................................................. 8 Set Up Test Session ............................................................................................................................... 8 Run Tests ............................................................................................................................................... 9 Generate Reports ................................................................................................................................. 10

Customizing QualiPHY ................................................................................................................................ 11 Copy Configuration ............................................................................................................................... 11 Select Tests .......................................................................................................................................... 12 Edit Variables ....................................................................................................................................... 13 Edit Test Limits ..................................................................................................................................... 14

X-Replay Mode ............................................................................................................................................ 15 QPHY-SAS2 Testing .................................................................................................................................. 16 Test Preparation ........................................................................................................................................... 16 Using Sierra for SAS Transmitter Testing .................................................................................................... 16

Configuring Sierra ................................................................................................................................ 16 Signaling the DUT ................................................................................................................................ 21 Data Block Selections .......................................................................................................................... 21

Using the SASWDP MATLAB Script............................................................................................................ 22 Installing the SASWDP Script .............................................................................................................. 22 Running SASWDP ............................................................................................................................... 22

QPHY-SAS2 Test Configurations ................................................................................................................. 23 1.5 Gbps TX Tests Using Live (Acquisition) Data ................................................................................ 23 1.5 Gbps TX Tests Using Saved Data ................................................................................................. 23 3.0 Gbps TX Tests Using Live (Acquisition) Data ................................................................................ 23 3.0 Gbps TX Tests Using Saved Data ................................................................................................. 23 6.0 Gbps TX Tests Using Live (Acquisition) Data ................................................................................ 23 6.0 Gbps TX Tests Using Saved Data ................................................................................................. 23 Demo of 6Gbps TX Tests Using Saved Data ....................................................................................... 23

QPHY-SAS2 Test Descriptions .................................................................................................................... 24 TX Group 1 Out of Band Tests 5.1.x (OOB) ........................................................................................ 24 TX Group 2 Spread Spectrum Clocking Tests ..................................................................................... 26

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TX Group 3 (Link Stability, Common Mode, … WDP) ......................................................................... 27 QPHY-SAS2 Variables ................................................................................................................................. 35 QPHY-SAS2 Limit Sets ................................................................................................................................ 36

SAS2-6G .............................................................................................................................................. 36 SAS2-3G .............................................................................................................................................. 36 SAS2-1.5G ........................................................................................................................................... 36

Appendix A: File Name Conventions for Saved Waveform Data .......................................................... 37 Appendix B: Manual Deskewing Procedures ......................................................................................... 38 Cable Deskewing Using the Fast Edge Output ........................................................................................... 38 Cable Deskewing Without the Fast Edge Output ........................................................................................ 41

Figures Figure 1. Connection Diagram when using Sierra to control DUT ................................................................ 2 Figure 2. QualiPHY framework dialog and Standard selection menu ........................................................... 6 Figure 3. The Test Report Summary Table and Details pages .................................................................... 10 Figure 4. Configuration Test Selector tab .................................................................................................... 12 Figure 5. X-Replay Mode window ................................................................................................................ 15 Figure 6. Example BER Map with WDP Results ......................................................................................... 22 Figure 7. Oscilloscope after Out of Band Tests ........................................................................................... 24 Figure 8. Oscilloscope after SSC Tests ....................................................................................................... 26 Figure 9. Oscilloscope after Phy Link Rate Stability Test ............................................................................ 28 Figure 10. Oscilloscope after the Common Mode RMS Voltage Test ......................................................... 29 Figure 11. Oscilloscope after the Vpp, VMA and EQ tests .......................................................................... 30 Figure 12. Oscilloscope after the Rise and Fall Times Test ........................................................................ 31 Figure 13. Oscilloscope after the Rj and Tj Tests ........................................................................................ 32 Figure 14. WDP Message Box .................................................................................................................... 33 Figure 15. Oscilloscope after the WDP Test ................................................................................................ 34

About This Manual This manual assumes that you are familiar with using an oscilloscope−in particular the Teledyne LeCroy oscilloscope that will be used with QualiPHY−and that you have purchased the QPHY-SAS2 software option. Some of the images in this manual may show QualiPHY products other than QPHY-SAS2, or were captured using different model oscilloscopes, as they are meant to illustrate general concepts only. Rest assured that while the user interface may look different from yours, the functionality is identical.


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Introduction QualiPHY is highly automated compliance test software meant to help you develop and validate the PHY (physical-electrical) layer of a device, in accordance with the official documents published by the applicable standards organizations and special interest groups (SIGs). You can additionally set custom variables and limits to test compliance to internal standards. QualiPHY is composed of a “framework” application that enables the configuration and control of separate tests for each standard through a common user interface. Features include:

• Multiple Data Source Capability

• User-Defined Test Limits to ensure devices are well within the passing region, even if subsequently measured with different equipment.

• Flexible Test Results Reporting that includes XML Test Record generation to better understand device performance distribution, or obtain process related information from the devices under test.

QPHY-SAS2 is a software package designed to capture, analyze, and report measurements in conformance with UNH IOL Serial Attached SCSI (SAS) Consortium SAS2 6Gbps Physical Layer Test Suite (Version 1.01). The software can be run on any Teledyne LeCroy oscilloscope with at least 13 GHz bandwidth, a sample rate of at least 40 GS/s on all four channels, and 20 MS memory.

Test Equipment Oscilloscope

• Teledyne LeCroy real-time oscilloscope, ≥ 13 GHz BW, installed with: o XStreamDSO v.6.1.x.x minimum* with an activated SAS2 option key o QualiPHY software v.6.1.x.x minimum with an activated QPHY-SAS2 component o SDAII** software option o MATLAB or MATLAB Component Run-Time (required for WDP test) o MATLAB Compiler Runtime v.7.7 (required for WDP test)

*Note: The version of XStreamDSO and QualiPHY software must match, so upgrade your version of QualilPHY if you have upgraded your oscilloscope firmware. The versions listed above are the minimum versions required for this product. QualiPHY and MATLAB may be installed on the oscilloscope or on a remote PC, but in either case both should be installed on the same host. All other software should be installed on the oscilloscope.

**Note: QPHY-SAS2 checks specifically for the SDAII option. This option is no longer available for newer Zi, Zi-A and Zi-B oscilloscopes. The QPHY-SAS3 product works with either SDAII or SDAIII software and will run all the same 1.5, 3.0, and 6.0 Gbps tests as QPHY-SAS2.

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Test Fixture and Cables • Wilder Technologies SAS Plug Adapter (SAS-TPA-P) or SAS Receptacle Adapter (SAS-TPA-R),

depending on the connection to the DUT (use SAS-TPA-R if using Sierra).

• 50Ω Coax Cable with SMA Male Connectors, Qty. 2 o These cables should be nominally the same length so that the attenuation

characteristics are well matched. The cables should be as short as possible, while allowing connection to the text fixtures and the oscilloscope (approx. 6 inches each).

o For the automated de-skew procedure employing the differential signals from the DUT, these cables must be matched to better than ½ UI of the data rate tested (e.g., less than ~160ps for 6 Gbps)

• PC power supply, Qty. 1

• DC Blocks, ≤ 10MHz to ≥ 18GHz (e.g., Pasternack PE8210), Qty. 2

Protocol Analyzer (Optional) The Teledyne LeCroy Sierra SAS Protocol Analyzer can be used to stimulate SAS2 targets to output the required test patterns for SAS2 transmitter testing. To do so, the following equipment is needed in addition to that listed above:

• Sierra SAS Protocol Analyzer installed with: o Teledyne LeCroy SAS Protocol Utility Suite o Sierra configuration files sas2 phy diagnostic page.sac, SAS2_PortA_Diagnostics.txt

and SAS2_PortB_Diagnostics.txt

• TF-SATA-C-KIT (including 4, small SSMP to SMA female cables)

• SATA cable (for connection to Sierra), Qty. 1

Figure 1. Connection Diagram when using Sierra to control DUT


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Remote Host Computer Requirements Usually, the oscilloscope is the host computer for the QualiPHY software, and all models that meet the acquisition requirements will also meet the host system requirements. However, if you wish to run the QualiPHY software from a remote computer, these minimum requirements apply:

• Operating System: o Windows 7 Professional o Windows 10 Professional

• 1 GHz or faster processor

• 1 GB (32-bit) or 2 GB (64-bit) of RAM

• Ethernet (LAN) network capability

• Hard Drive: o At least 100 MB free to install the framework application o Up to 2 GB per standard installed to store the log database (each database grows from a

few MB to a maximum of 2 GB) See Set Up Remote Control for configuration instructions.

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Installation and Setup QualiPHY is a Windows-based application that can be configured with one or more serial data compliance components. Each compliance component is purchased as a software option.

Install Base Application Download the latest version of the QualiPHY software from: teledynelecroy.com/support/softwaredownload under Oscilloscope Downloads > Software Utilities. If the oscilloscope is not connected to the Internet, copy the installer onto a USB memory stick then transfer it to the oscilloscope desktop or a folder on a D:\ drive to execute it. Run QualiPHYInstaller.exe and follow the installer prompts. Choose all the components you plan to activate. If you omit any components now, you will need to update the installation to activate them later. By default, the oscilloscope appears as local host when QualiPHY is executed on the oscilloscope. Follow the steps under Add Connection to QualiPHY to check that the IP address is 127.0.0.1.

Activate Components The serial data compliance components are factory installed as part of the main application in your oscilloscope and are individually activated through the use of an alphanumeric code uniquely matched to the oscilloscope’s serial number. This option key code is what is delivered when purchasing a software option. To activate a component on the oscilloscope:

1. From the menu bar, choose Utilities > Utilities Setup. 2. On the Options tab, click Add Key. 3. Use the Virtual Keyboard to Enter Option Key, then click OK.

If activation is successful, the key code now appears in the list of Installed Option Keys. 4. Restart the oscilloscope application by choosing File > Exit, then double-clicking the Start DSO

icon on the desktop.

Set Up Dual Monitor Display Teledyne LeCroy recommends running QualiPHY on an oscilloscope equipped with Dual Monitor Display capability. This allows the waveform and measurements to be shown on the oscilloscope LCD display while the QualiPHY application and test results are displayed on a second monitor. See the oscilloscope Operator’s Manual or Getting Started Manual for instructions on setting up dual monitor display.


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Set Up Remote Control QualiPHY software can be executed from a remote host computer, controlling the oscilloscope through a LAN Connection. To set up remote control:

• The oscilloscope must be connected to a LAN and assigned an IP address (fixed or dynamic).

• The host computer must be on the same LAN as the oscilloscope.

Configure Oscilloscope for Remote Control Note: This component contains script generation files for specific equipment used with the oscilloscope to perform the compliance test. To allow automation of such equipment, QualiPHY software should be installed on the oscilloscope even if it’s run from a remote computer.

1. From the menu bar, choose Utilities Utilities Setup... 2. Open the Remote tab and set Remote Control to TCP/IP. 3. Verify that the oscilloscope shows an IP address.

Add Connection to QualiPHY 1. On the host PC, download and run QualiPHYInstaller.exe. 2. Start QualiPHY and click the General Setup button. 3. On the Connection tab, click Scope Selector. 4. Click Add and choose the connection type. Enter the oscilloscope IP address from Step 3

above. Click OK. 5. When the oscilloscope is properly detected, it appears on the Scope Selector dialog. Select the

connection, and click OK.

QualiPHY is now ready to control the oscilloscope.

Select Connection Multiple oscilloscopes may be accessible to a single remote host. In that case, go to General Setup and use the Scope Selector at the start of the QPHY session to choose the correct connection. QualiPHY tests the oscilloscope connection when starting a test. The system warns you if there is a connection problem.

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Using QualiPHY This section provides an overview of the QualiPHY user interface and general procedures. For detailed information about the QPHY-SAS2 software option, see QPHY-SAS2 Testing.

Accessing the Software Once QualiPHY is installed and activated, it can be accessed from the oscilloscope menu bar by choosing Analysis > QualiPHY, or by double-clicking the QualiPHY desktop icon on a remote computer. The QualiPHY framework dialog illustrates the overall software flow, from general set up through running individual compliance tests. Work from left to right, making all desired settings on each sub-dialog. The sub-dialogs are organized into tabs each containing configuration controls related to that part of the process. These are described in more detail in the following sections. If Pause on Failure is checked, QauliPHY prompts to retry a measure whenever a test fails. Report Generator launches the manual report generator dialog. The Exit button at the bottom of the framework dialog closes the QualiPHY application.

Figure 2. QualiPHY framework dialog and Standard selection menu


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General Setup The first sub-dialog contains general system settings. These remain in effect for each session, regardless of Standard, until changed.

Connection tab Shows IP Address of the test oscilloscope (local host 127.0.0.1 if QualiPHY is run from the oscilloscope). The Scope Selector allows you to choose the oscilloscope used for testing when several are connected to the QualiPHY installation. See Set Up Remote Control for details.

Session Info tab Optional information about the test session that may be added to reports, such as: Operator Name, Device Under Test (DUT), Temperature (in °C) of the test location, and any additional Comments. There is also an option to Append Results or Replace Results when continuing a previous session.

To optimize report generation, enter at least a DUT name at the beginning of each session.

Report tab Settings related to automatic report generation. Choose:

• Reporting behavior of: o “Ask to generate a report after tests,” where you’ll be prompted to create a new file for

each set of test results. o “Never generate a report after tests,” where you’ll need to manually execute the Report

Generator to create a report. o “Always generate a report after tests,” to autogenerate a report of the latest test results.

• Default report output type of XML, HTML, or PDF.

• A generic Output file name, including the full path to the report output folder. Optionally, check Allow style sheet selection in Report Generator to enable the use of a custom .xslt when generating reports (XML and HTML output only). The path to the .xslt is entered on the Report Generator dialog. Report Generator launches the Report Generator dialog, which contains the same settings as the Report tab, only applied to individual reports.

Advanced tab This tab launches the X-Replay Mode dialog. See X-Replay Mode.

About tab Information about your QualiPHY installation.

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QualiPHY Test Process Once general system settings are in place, these are the steps for running test sessions.

Set Up Test Session 1. Connect the oscilloscope to the DUT. See QPHY-SAS2 Testing Physical Setup. 2. Access the QualiPHY software to display the framework dialog.

3. If running QualiPHY remotely, click General Setup and open the Scope Selector to select the

correct oscilloscope connection. 4. If you have more than one component activated, click Standard and select the desired standard

to test against. Otherwise, your one activated component will appear as the default selection. Note: Although all the QualiPHY components appear on this dialog, only those selected when installing QualiPHY are enabled for selection.

5. Click the Configuration button and select the test configuration to run. These pre-loaded configurations are set up to run all the tests required for compliance and provide a quick, easy way to begin compliance testing. See QPHY-SAS2 Test Configurations for a description of your configurations. You can also create custom configurations for internal compliance tests by copying and modifying the pre-loaded configurations. See Customizing QualiPHY for details.

6. Close the Edit/View Configuration dialog to return to the framework dialog.


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Run Tests 1. On the framework dialog, click Start to begin testing.

When tests are in progress, this button changes to Stop. Click it at any time to stop the test in process. You’ll be able to resume from the point of termination or from the beginning of the test.

2. Follow the pop-up window prompts. QualiPHY guides you step-by-step through each of the tests described in the standard specification, including diagrams of the connection to the DUT for each required test mode.

3. When all tests are successfully completed, both progress bars on the framework dialog are completely green and the message “All tests completed successfully” appears. If problems are encountered, you’ll be offered options to:

• Retry the test from the latest established point defined in the script

• Ignore and Continue with the next test

• Abort Session

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Generate Reports The QualiPHY software automates report generation. On the framework dialog, go to General Setup > Report to pre-configure reporting behavior. You can also manually launch the Report Generator from the framework dialog once a test is run. The Report Generator offers the same selections as the Report tab, only applied to each report individually, rather than as a system setting. This enables you to save reports for each test session, rather than overwrite the generic report file. There are also options to link a custom style sheet (.xslt) to the report, or to Exclude Informative Results. The Test Report includes a summary table with links to the detailed test result pages.

Figure 3. The Test Report Summary Table and Details pages

Reports are output to the folder D:\QPHY\Reports, or C:\LeCroy\QPHY\Reports if QualiPHY is installed on a remote PC. You can add your own logo to the report by replacing the file *\QPHY\StyleSheets\CustomerLogo.jpg. The recommended maximum size is 250x100 pixels at 72 ppi, 16.7 million colors, 24 bits. Use the same file name and format.


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Customizing QualiPHY Create custom test configurations by copying one of the standard configurations and modifying it. The pre-loaded configurations cannot be modified.

Copy Configuration 1. Access the QualiPHY framework dialog and select a Standard. 2. Click Edit/View Configuration and select the configuration upon which to base the new

configuration. This can be a pre-loaded configuration or another copy. 3. Click Copy and enter a name and description. Once a custom configuration is defined, it

appears on the Configuration tab with the defined name. Note: Until you enter a new name, the new configuration is shown followed by “(Copy)”.

4. Select the new, custom configuration and follow the procedures below to continue making changes. Note: When any configuration is changed, the Save As button at the bottom of the Configuration tab becomes active. When a custom configuration is changed, the Save button also becomes active to apply the changes to the existing configuration, rather than make another copy.

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Select Tests On the Test Selector tab, check the tests that make up the configuration. Each test is defined by the SAS2 standard. A description of each test is displayed when it is selected. To loop an individual test or group of tests, select it from the list, then choose to loop indefinitely until stopped or enter the number of repetitions. When defining a number of repetitions, enter the number of repetitions before enabling the checkbox.

Figure 4. Configuration Test Selector tab


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Edit Variables The Variable Setup tab contains a list of test variables. See QPHY-SAS2 Variables for a description of each. To modify a variable:

1. Select the variable on the Variable Setup tab, then click Edit Variable. (You can also choose to Reset to Default at any time.)

2. The conditions of this variable appear on a pop-up. Choose the new condition to apply.

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Edit Test Limits The Limits tab shows the Limit Set currently associated with the configuration. Any limit set can be associated with a custom configuration by selecting it in this field. The Limits Manager shows the settings for every test limit in a limit set. Those in the default set are the limits defined by the standard. To create a custom limit set:

1. On the Limits tab, click Limits Manager. 2. With the default set selected, click Copy Set and enter a name.

Note: You can also choose to copy and/or modify another custom set that has been associated with this configuration.

3. Double click the limit to be modified, and in the pop-up enter the new values.

You can also Import Limits from a .csv file. Navigate to the file location after clicking the button. Tip: Likewise, Export Limits creates a .csv file from the current limit set. You may wish to do this and copy it to format the input .csv file.


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X-Replay Mode The X-Replay mode window is an advanced (“developer”) view of QualiPHY. The tree in the upper-left frame enables you to navigate to processes in the SAS2 test script, in case you need to review the code, which appears in the upper-right frame. Two other particularly useful features are:

• A list of recent test sessions in the lower-left frame. While you can only generate a report of the current test session in the QualiPHY wizard, in X-Replay Mode you can generate a report for any of these recent sessions. Select the session and choose Report > Create Report from the menu bar.

• The QualiPHY log in the bottom-right frame. The frame can be split by dragging up the lower edge. The bottom half of this split frame now shows the raw Python output, which can be useful if ever the script needs debugging.

Figure 5. X-Replay Mode window

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QPHY-SAS2 Testing

Test Preparation Before beginning any data acquisition or test, warm the oscilloscope for at least 20 minutes. Calibration is performed automatically by the oscilloscope software; no manual calibration is required. The calibration procedure will be run again if the temperature of the oscilloscope changes by more than a few degrees. The QPHY-SAS2 script requires that you place the DUT (Device Under Test) in the required test modes. The script will prompt you to do so before each specific test, but it is recommended that you ensures the DUT is capable of being placed in the required test modes before beginning testing.

Using Sierra for SAS Transmitter Testing

Configuring Sierra See Optional Equipment for the equipment required to use the Sierra for SAS testing. Do the following to prepare the protocol analyzer to control the DUT during testing:

1. Be sure the SAS Protocol Suite utility supplied with the Sierra is installed. (The directories below may change depending upon your installation choices.)

2. Copy the sas2 phy diagnostic page.sac file to C:\Users\Public\Documents\LeCroy\SAS Protocol Suite\User.

3. Copy the SAS2_PortA_Diagnostics.txt and SAS2_PortB_Diagnostics.txt files to C:\Users\Public\Documents\LeCroy\SAS Protocol Suite\System\DataBlock.

4. Connect the SAS2 device primary port output to the T1 front-panel connector of the Sierra. The primary port is closest to the center of the SAS2 multi-pin connector.

a. The Teledyne LeCroy TF-SATA-C test fixture is required to connect the SMA connectors of the Wilder Tech test fixture to the SATA connector on the front of the Sierra.

b. Test signals will be available on the secondary port.

5. Power on both the SAS2 device and the Sierra.


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6. Open the Teledyne LeCroy SAS Protocol Suite utility.

7. From the menu bar, choose Tools > Find Device. You will see the dialog below.

8. Set Find Device in T1 and click the Find device button.

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9. When the following warning appears, choose Yes.

The resulting operation can take up to 30 seconds. If the search for a device succeeds, the device is added to the Device List at the left of the window, with the SAS Address shown.

10. Record the address shown in the Device List.

11. Close the Device Identifier window.


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12. From the menu bar, choose File > Open and select the sas2 phy diagnostic page.sac file. Note: This file contains the SCSI commands and diagnostic information you will need to control the device’s diagnostic modes The file should be in the default directory, where it was previously copied.

13. In the Target SAS Address field, enter the address previously recorded from the Device Identifier screen.

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14. From the menu bar, choose Configuration > Data Block.

15. Click the Delete All button to delete the current data block information

16. Click the Load button (lower right corner) to select the new data blocks to load:

a. Load SAS2_PortA_Diagnostics.txt for the A (primary) port.

b. Load SAS2_PortB_Diagnostics.txt for the B (secondary) port.

17. Click the lower ‘X’ in the upper right hand corner to close the data block window.

18. Click Yes to save the changes to the data block.


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Signaling the DUT In the SAS Protocol Suite window, click the arrow to the right side of the Payload Data field to display a list of available commands to send the target under test. At power-on of the SAS2 device, it should be in the “stopped” mode. In this mode it will be transmitting the “Out of Band” signal (common to all 3 speeds of SAS2). You can also force the device into this mode by sending the A_STOP_COMINIT data block. These data blocks are defined in the SAS2 specification, but have been supplied here for your convenience. You can select the data block for a give test signal using the pull-down under the Payload Data field. Note: To enter any test mode which is NOT OOB or Stopped, you must first set the device in the Stopped state (send A_STOP_COMINIT data block), and then send the block desired.

Data Block Selections A_STOP_COMINIT Used to stop the current data output and return to OOB state.

A6G_SCR_0 Sends the 6Gbps Scrambled Zero Pattern

A6G_HFTP Sends the 6Gbps HFTP Pattern

A6G_MFTP Sends the 6Gbps MFTP Pattern

A6G_Idle Sends the 6Gbps Electrical Idle Pattern

A6G_D30p3 Sends the 6Gbps D30.3 Pattern

A6G_CJTPAT Sends the 6Gbps CJTPAT Pattern

A6G_HFTP_DOWN Sends the 6Gbps HFTP with SSC Down spreading Pattern

A6G_HFTP_CENTER Sends the 6Gbps HFTP with SSC Center spreading Pattern

A6G_MFTP_DOWN Sends the 6Gbps MFTP with SSC Down spreading Pattern

A6G_MFTP_CENTER Sends the 6Gbps MFTP with SSC Center spreading Pattern

A3G_SCR_0 Sends the 3Gbps Scrambled Zero Pattern

A3G_HFTP Sends the 3Gbps HFTP Pattern

A3G_MFTP Sends the 3Gbps MFTP Pattern

A3G_Idle Sends the 6Gbps Electrical Idle Pattern

A3G_D30p3 Sends the 3Gbps D30.3 Pattern

A3G_CJTPAT Sends the 3Gbps CJTPAT Pattern

A3G_HFTP_DOWN Sends the 3Gbps HFTP with SSC Down spreading Pattern

A3G_HFTP_CENTER Sends the 3Gbps HFTP with SSC Center spreading Pattern

A3G_MFTP_DOWN Sends the 3Gbps MFTP with SSC Down spreading Pattern

A3G_MFTP_CENTER Sends the 3Gbps MFTP with SSC Center spreading Pattern

A1p5G_SCR_0 Sends the 1.5Gbps Scrambled Zero Pattern

A1p5G_HFTP Sends the 1.5Gbps HFTP Pattern

A1p5G_MFTP Sends the 1.5Gbps MFTP Pattern

A1p5G_Idle Sends the 1.5Gbps Electrical Idle Pattern

A1p5G_D30p3 Sends the 1.5Gbps D30.3 Pattern

A1p5G_CJTPAT Sends the 1.5Gbps CJTPAT Pattern

A1p5G_HFTP_DOWN Sends the 1.5Gbps HFTP with SSC Down spreading Pattern

A1p5G_HFTP_CENTER Sends the 1.5Gbps HFTP with SSC Center spreading Pattern

A1p5G_MFTP_DOWN Sends the 1.5Gbps MFTP with SSC Down spreading Pattern

A1p5G_MFTP_CENTER Sends the 1.5Gbps MFTP with SSC Center spreading Pattern

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Using the SASWDP MATLAB Script The SASWDP MATLAB script is required to run the Waveform Distortion Penalty (5.3.9) test. This script can be obtained from the T10 organization website (http://www.t10.org/cgi-bin/ac.pl). A valid T10 login is required to download the file from T10.

Installing the SASWDP Script SASWDP.m must be run from the same directory as the stressor, symbol and waveform data files. Note: The stressor file is included in the .zip download from the T10 website and is also included with QPHY-SAS3, although the MATLAB script itself is not. The symbol and waveform data files are created as the WDP test is run from QPHY-SAS3. If MATLAB is running on the oscilloscope, unzip 09-015r0.zip to D:\Waveforms\SAS3 and confirm Path to Saved Waveforms for Offline Test is set to this directory. If MATLAB is running on a remote PC:

• Unzip 09-015r0.zip to a directory on the PC that is accessible to MATLAB.

• Copy the sas3_symbol.txt and sas3_waveformData.txt files to the same directory.

Running SASWDP Due to licensing issues, you must execute the SASWDP.m script manually; QualiPHY does not automate the process. Enter the value for xWDP that is reported on the BER Map in the WDP dialog box that appears when running TX 5.3.9 Waveform Distortion Penalty.

Figure 6. Example BER Map with WDP Results

(Figure 5.3.9-3 from UNH-IOL SAS-2 6Gbps Physical Layer Test Suite).

http://www.t10.org/cgi-bin/ac.pl


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QPHY-SAS2 Test Configurations Test configurations include variable settings, limit sets, and test selections. See QPHY-SAS2 Variables for a description of each variable and its default value.

1.5 Gbps TX Tests Using Live (Acquisition) Data This configuration will run all of the tests except for the deskew tests and the WDP test. The limit set in use is SAS2-1.5G. All variables are set to their defaults, except Bitrate is set to 1.5e9.

1.5 Gbps TX Tests Using Saved Data This configuration will run all of the tests except for the deskew tests and the WDP test. The limit set in use is SAS2-1.5G. All variables are set to their defaults, except Bitrate is set to 1.5e9 and Test Mode is set to Use Saved Data.

3.0 Gbps TX Tests Using Live (Acquisition) Data This configuration will run all of the tests except for the deskew tests and the WDP test. The limit set in use is SAS2-3G. All variables are set to their defaults, except Bitrate is set to 3e9.

3.0 Gbps TX Tests Using Saved Data This configuration will run all of the tests except for the deskew tests and the WDP test. The limit set in use is SAS2-3G. All variables are set to their defaults, except Bitrate is set to 3e9 and Test Mode is set to Use Saved Data.

6.0 Gbps TX Tests Using Live (Acquisition) Data This configuration will run all of the tests except for the deskew tests and the WDP test. The limit set in use is SAS2-6G. All variables are set to their defaults, except Bitrate is set to 6e9.

6.0 Gbps TX Tests Using Saved Data This configuration will run all of the tests except for the deskew tests and the WDP test. The limit set in use is SAS2-6G. All variables are set to their defaults, except Bitrate is set to 6e9 and Test Mode is set to Use Saved Data.

Demo of 6Gbps TX Tests Using Saved Data This configuration will run all TX tests on demo waveforms (available from Teledyne LeCroy). The limit set in use is SAS2-6G. All variables are set to their defaults, except: Bitrate is 6e9, Test Mode is Use Saved Data, Saved Waveform Path is D:\Waveforms\SAS2\Demo, and Demo Mode is Yes. Place demo waveforms in the Saved Waveform Path folder.

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QPHY-SAS2 Test Descriptions TX Group 1 Out of Band Tests 5.1.x (OOB) There are four tests run in this group:

• TX Maximum Noise During OOB Idle

• TX OOB Burst Amplitude

• TX OOB Offset Delta

• TX OOB Common Mode Delta At the completion of the Out of Band Tests, the oscilloscope is in the following state:

Figure 7. Oscilloscope after Out of Band Tests

Shown on screen:

• F3 is the Idle Differential Signal, representing the idle portion of the differential OOB signal.

• F4 is the Burst Differential Signal, representing the burst portion of the differential OOB signal after it is filtered by a 4.5GHz low-pass Butterworth filter. Having two differential signal traces allows us to perform the measurement on the idle and the burst separately.

• F5 is the Burst Common Mode signal.

• F6 is the Wide Band AM Demodulated Differential Signal. This is used for the separation of the idle portion from the burst portion.


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• F7 is the Idle Common Mode signal. This is calculated by summing the two inputs and dividing them by 2.

• F8 is a view of the Differential Signal after it has been filtered by the 4.5GHz low-pass Butterworth filter. This is calculated by subtracting the negative input from the positive input. This signal is used to create many of the traces described earlier.

In the Measure table:

• IdleNoise (P1) is the peak-to-peak measurement of F3 (idle differential signal). This is the measured value for TX – Max Noise During Idle (5.1.2). Value must be less than 120mV(P-P) to pass the test.

• OffsetDelta (P3) is the mean amplitude of F4 (burst differential signal). This is the measured value for TX- OOB Offset Delta (5.1.4). Value must be between -25mV and 25mV (inclusive) to pass the test.

• BurstAmpl (P4) is the peak-to-peak value of F4 (burst differential signal). This is the measured value for TX – Max Burst Amplitude and TX – Min Burst Amplitude (5.1.3). Maximum value must be less than 1.6V and minimum value must be great than 240mV to pass this test.

• CMMdelta (P7) is the difference between the mean of the Burst Common Mode Signal (F5) and the Idle Common Mode Signal (F7). This is the measured value for TX - OOB Common Mode Delta (5.1.5). Value must be between +/- 50mV to pass this test.

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TX Group 2 Spread Spectrum Clocking Tests There are two tests run in this group:

• Test Down Spreading (HFTP-SSC-DOWN)

• Test Center Spreading (HFTP-SSC-CENTER The purpose of these tests is to verify the SSC Modulation Frequency, Modulation Deviation and Balance, and DFDT are within the specification limits. At the completion of each Spread Spectrum Clocking test, the oscilloscope is in the following state:

Figure 8. Oscilloscope after SSC Tests

Shown on the screen:

• F2 is the SSCTrack of the input filtered by a 4th order Butterworth filter with a 200kHz cutoff as described by the specification.

• F3 is the SSCTrack of the input without the effects of the 4th order Butterworth filter used by F2.

• F4 is the Rate of Frequency Modulation (dF/dT). This is calculated as: slope = (f(t)–f(t–0.27us))/0.27 us).


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• Max Freq and Min Freq (P1 and P2) are calculated by measuring the minimum and maximum of the Unfiltered SSCTrack (F3). These are the measured values for TX - SSC Mod Freq Min and TX - SSC Mod Freq Max (5.2.3). These values must be in between +/- 2400 kppm to pass this test for center spreading, between -100 ppm and 2400 ppm for up spreading, and -2400 ppm and 100 ppm for down spreading.

• Variation P-P (P3) is the difference between the Max Freq and Min Freq of the Unfiltered SSCTrack. This is the measured value for TX - Variation P-P (5.2.3). This is shown for information only.

• Mod Freq (P7) is calculated by measuring the frequency @ level of the Filtered SSCTrack (F2). This is the measured value for TX - SSC Mod Freq (5.2.2). This value must be between 30kHz and 33kHz (inclusive) to pass this test.

• MinDFDT and MaxDFDT (P9 and P10) are calculated by measuring the minimum and maximum of the DFDT (F3). This is the measured value for TX- SSC DFDT Min and TX- SSC DFDT Max (5.2.4). Values must be between +/-850pm/us to pass this test.

• Imbalance (P12) is measure of the deviation asymmetry of the DFDT. It is measured by taking the absolute value of the sum of the averaged max peak level and the averaged min peak level. This is the measured value of TX – Deviation Asymmetry (5.2.3). This value must be between +/- 288 ppm to pass this test. This test is only required on SSC with center spreading.

TX Group 3 (Link Stability, Common Mode, … WDP) There are seven tests run in this group:

• TX 5.3.1 Phy Link Rate Stability (HFTP)

• TX 5.3.2 Common Mode RMS Voltage (CJTPAT)

• TX 5.3.4 and 5.3.5 Vpp, VMA, EQ (D30.3)

• TX 5.3.6 Rise and Fall Times (HFTP)

• TX 5.3.7 RJ, (a. MFTP, b. MFTP-SSC-DOWN, c. MFTP-SSC-CENTER)

• TX 5.3.8 TJ, (a. MFTP, b. MFTP-SSC-DOWN, c. MFTP-SSC-CENTER)

• TX 5.3.9 Waveform Distortion Penalty The first six tests are included in the preloaded configurations. Tests 5.3.7 RJ and 5.3.8 TJ are each run three times for a. MFTP no SSC, b. MFTP with Down-Spreading SSC, and c. MFTP with Center-Spreading SSC. Test 5.3.9 Waveform Distortion Penalty requires the MATLAB SASWDP script. Because of licensing issues, this test is not part of any preloaded configuration but may be added to a custom configuration. The tests are described on the following pages.

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TX 5.3.1 Phy Link Rate Stability (HFTP) The purpose of this test is to characterize the quality and consistency of the transmitter’s reference clock by measuring the physical link rate long-term stability. At the completion of the Phy Link Rate Stability test, the oscilloscope is in the following state:

Figure 9. Oscilloscope after Phy Link Rate Stability Test


• F2 is the SSCTrack of the input. This signal is filtered by a 1st order Butterworth filter with a 3.7 MHz cutoff as described by the specification. The first division of the result is discarded to allow for clock recovery “capture” as well as settling of the startup effect of the filter. This is the same as creating the SSCTrack, however, when SSC is not enabled on the device, we can use this to calculate the long term stability.

In the Measure table: • P1 and P2 are used to calculate the Min and the Max of F2. These are the measured values for

TX – Min Phy Link Rate Stability (5.3.1) and TX – Max Phy Link Rate Stability (5.3.1). Values must be between +/- 100ppm to pass this test.


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TX 5.3.2 Common Mode RMS Voltage (CJTPAT) The purpose of this test is to verify that common-mode RMS voltage is within the specification limits. At the completion of the Common Mode RMS Voltage test, the oscilloscope is in the following state:

Figure 10. Oscilloscope after the Common Mode RMS Voltage Test

In the Measure section:

• CM Offset (P1) is the common mode offset. This is measured by taking the mean of the common mode trace. This is the measured value of TX – Common Mode Offset (5.3.2). This test is informational only.

• CM RMS (P2) is the common mode RMS voltage. This is measured by taking the RMS of the common mode trace. This is the measured value for TX – CM RMS voltage (5.3.2). Value must be less than 30mV to pass this test.

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TX 5.3.4 and 5.3.5 Vpp, VMA, EQ (D30.3) The purpose of these tests is to verify that the peak-to-peak voltage, the voltage modulation amplitude and the amount of equalization are within the specification limits. At the completion of the Vpp, VMA and EQ tests, the oscilloscope is in the following state:

Figure 11. Oscilloscope after the Vpp, VMA and EQ tests


• F2 is Eye Diagram created from the input signal using a 2-pole PLL with a natural frequency of 3.9 MHz and a damping factor of .800. This is shown for information only.

• F4 is a histogram of the input waveform.

• F5 is this histogram converted to a waveform (this is required to perform certain measurements on the histogram).

• F6 is the differential input waveform, calculated by subtracting the negative input from the positive input.


• Vpp (P1) is measuring the full range of the F4 histogram. This is the measured result for TX - Vpp (5.3.4). Value must be between 850 mV and 1.2 V to pass this test.

• LowMode (P4) is the maximum peak from the left side of the F5 waveform. This represents the de-emphasized low voltage level of the signal.

• HighMode (P5) is the maximum peak from the right side of the F5. This represents the de-emphasized high voltage level of the signal. These are used to calculate the VMA.


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• VMA (P6) is the difference between the 2 modes of the histogram. This is the measured value of TX - VMA (5.3.5). Value must be less than 600 mV to pass this test.

• EQ (P8) is calculated as 20*log10(Vp-p/VMA). This is the measured value of TX - EQ (5.3.5). Value must be between 2 and 4 dB to pass this test.

TX 5.3.6 Rise and Fall Times (HFTP) The purpose of this test if to verify that the rise and fall times are within the specification limits. After the completion of this test the oscilloscope is in the following configuration:

Figure 12. Oscilloscope after the Rise and Fall Times Test


• F1 is the differential input waveform.

• F4 is the histogram of all of the measured 20-80 rise times.

• Z2 is a zoom of F1. In the Measure table:

• Rise 20-80 (P1) is 20-80 rise time of the differential input waveform (F1).

• Fall 80-20 (P2) is the 80-20 fall time of the differential input waveform (F1).

• Rise(UI) (P3) is the 20-80 rise time converted to Unit Interval. This is the measured value of TX - Trise (20-80) (5.3.6). The mean of this value for all rising edges in the differential input must be greater than .25UI to pass this test.

• Fall(UI) (P4) is the 80-20 fall time converted to Unit Interval. This is the measured value of TX - Tfall (80-20) (5.3.6). The mean of this value for all falling edges in the differential input must be greater than .25UI to pass this test.

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TX 5.3.7 RJ and 5.3.8 TJ (MFTP, MFTP-SSC-DOWN, MFTP-SSC-CENTER) The purpose of these tests is to verify that Random and Total Jitter are within specification limits. Both tests are run for all supported SSC modes (No SSC, SSC Down-Spreading, SSC Center-Spreading). At the completion of the tests, the oscilloscope is in the following state:

Figure 13. Oscilloscope after the Rj and Tj Tests

Shown on this screen:

• F1 is the differential input waveform.

• RjBUjHist is the histogram of the random and bounded uncorrelated jitter. This is the same as the full TIE histogram with the DDj removed. The RjBUjHist is an output from SDA II.

In the SDA Jitter table:

• Tj(1e-12), Rj(sp), Dj(sp), Bitrate, Pj and DCD are shown. These are all calculations from SDA II. Only the Rj(sp) and Dj(sp) parameters are used for further calculation. The rest of the parameters are informational only.

• Rj(sp) is the measured value for TX - RJ (1-sigma) (5.3.7) using the “spectral” method. This is report for information only.


• Rj(14sigma) (P8) is calculated by multiplying Rj(sp) by 14. The resulting value is multiplied by 6e9 to convert to unit intervals. This is the measured value for TX- Rj14Sigma (5.3.7). This value must be less than 150mUI to pass this test.

• Dj(SAS2) (P9) converts Dj(sp) to unit intervals by multiplying by 6e9.

• Tj(SAS2) is the sum of Rj(14sigma) and Dj(SAS2) (as described in the specification). This is the measured value for TX – Tj (5.3.8). This value must be less than 250mUI to pass this test.


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TX 5.3.9 Waveform Distortion Penalty The purpose of this test is to verify that the Waveform Distortion Penalty is within specification limits. Note: This test requires MATLAB script SASWDP (see Using the SASWDP Script).Due to licensing issues, it cannot be run automatically by QPHY-SAS2; you manually run the script, then report the result to QPHY-SAS2 to complete the measurement. For this reason, the WDP test is not included in any of the preloaded configurations. Create a custom configuration to run this test. When the test is run, the following dialog appears:

Figure 14. WDP Message Box

At this point, run the SASWDP script and enter the returned value in the dialog. By entering this value, the result for the WDP test can be included in the test report provided by QualiPHY.

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At the completion of this test the oscilloscope is in the following state:

Figure 15. Oscilloscope after the WDP Test


• F1 is the differential input waveform. This is calculated by subtracting the negative input waveform from the positive input waveform.

• F2 is the resampled and interpolated waveform with exactly 16 evenly spaced samples per UI. This waveform is also averaged to reduce Rj. This is all done in accordance with the specification. The waveform is saved in the required input format for the SASWDP script in oscilloscope D:\Waveforms\SAS2.

In the measure table:

• WDP (P1) is the value that was entered in the WDP message box, which should be the value that was the output from the SASWDP script. This is the measured value for TX-WDP (5.3.9). Value must be less than 13 dB to pass this test.

• Patt Length (P3) is an output of the pattern length of the input waveform. This can be used to ensure that a pattern of the appropriate length was sent from the DUT.


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QPHY-SAS2 Variables Use the Upper (A) or Lower (B) Inputs? Specifies whether to use the “A” row or “B” row of inputs to run the selected tests. Default is InputA.

Bitrate for SAS2 Specifies the bitrate used for testing. Default is 6e9.

Demo Mode This variable allows the user to run the tests in Demo Mode using demo waveforms (available from Teledyne LeCroy) stored in the \Demo subfolder of the Saved Waveform Path folder. When running in Demo Mode, the user is still prompted with connection diagrams based on other variable selections so as to experience running the test as it would be run on live signals. Default is No.

Is Device a Target or an Initiator? Specifies whether the DUT is a target or initiator. This is use to generate the proper connection diagram. Default is Target.

Port (A or B) Being Tested Specifies whether the port being tested is the Primary (A) or Secondary (B) port. This is use to generate the proper connection diagram. Default is Secondary.

Path to Saved Waveforms for Offline Test Full path to the root folder in which to store waveform files, or from which to recall waveform files when Test Mode is Use Saved Data. The default is oscilloscope D:\Waveforms\SAS2\. Note: This path must end in a back slash, since subfolders may be appended to it during testing.

Save Individual Runs? When set to Yes, acquired waveforms will be saved in a separate folder for each test run. For example: D:\Waveforms\SAS2\[Device Under Test]\Run1. When set to No, waveforms will be overwritten on every run and saved in: D:\Waveforms\SAS2\[Device Under Test]. This setting has no effect when testing on saved waveforms. Default is No.

Stop on Test to Review Results? When set to Yes, the QualiPHY script stops after each test allowing you to view the results. Any new acquisition made while QualiPHY is stopped may cause the script to produce unexpected results. Default is No.

Test Mode Specifies whether to Acquire New Data prior to testing or Used Saved Waveforms stored in the Saved Waveform Path folder. The default is Acquire New Data.

TX Negative Source Channel used to input source TX negative signal. Default is C3.

TX Positive Source Channel used to input source TX positive signal. Default is C2.

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QPHY-SAS2 Limit Sets The default installation of QPHY-SAS2 contains the following limit sets:

SAS2-6G Limits defined by standard for 6 Gbps tests.

SAS2-3G Limits defined by standard for 3 Gbps tests.

SAS2-1.5G Limits defined by SAS2 standard for 1.5 Gbps tests.


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Appendix A: File Name Conventions for Saved Waveform Data The following files are saved when running SAS2 tests on newly acquired data. To perform tests using this package on previously acquired data, the files must be renamed to conform to these conventions: Please note (at this time) there is no distinction between bit rates, so please use different folders for results at 6, 3 and 1.5 Gbps. Note: Files have semi-rigid record length (time duration) requirements, shown in the table below.

Test Signal Type TX+ TX- Recommended Record Duration

Out of Band or COMINIT OOB_p.trc OOB_n.trc 1 microsecond (or 100ns/div)

Compliance Jitter Test Pattern CJTPAT_p.trc CJTPAT_p.trc 100 microseconds (or 10usec/div)

High Frequency Test Pattern (10101010…)

HFTP_p.trc HFTP_n.trc 500 microseconds (or 50us/div)

High Frequency Test Pattern (10101010…) with SSC down-spreading

HFTP-SSC-DOWN_p.trc HFTP-SSC-DOWN_n.trc 500 microseconds (or 50us/div)

High Frequency Test Pattern (10101010…) with SSC center-spreading

HFTP-SSC-CENTER_p.trc HFTP-SSC-CENTER_n.trc 500 microseconds (or 50us/div)

High Frequency Test Pattern (10101010…) with SSC up-spreading

HFTP-SSC-UP_p.trc HFTP-SSC-UP_n.trc 500 microseconds (or 50us/div)

Medium Frequency Test Pattern (11001100…)

MFTP_p.trc MFTP_n.trc 500 microseconds (or 50us/div)

Medium Frequency Test Pattern (11001100…) with SSC down-spreading

MFTP-SSC-DOWN_p.trc MFTP-SSC-DOWN_n.trc 500 microseconds (or 50us/div)

Medium Frequency Test Pattern (11001100…) with SSC center-spreading

MFTP-SSC-CENTER_p.trc MFTP-SSC-CENTER_n.trc 500 microseconds (or 50us/div)

Medium Frequency Test Pattern (11001100…) with SSC up-spreading

MFTP-SSC-UP_p.trc MFTP-SSC-UP_n.trc 500 microseconds (or 50us/div)

Scrambled Zero SCR_0_p.trc SCR_0_n.trc 100 microseconds (or 10usec/div)

D30.3 pattern D30p3_p.trc D30p3_n.trc 100 microseconds (or 10usec/div)

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Appendix B: Manual Deskewing Procedures

Cable Deskewing Using the Fast Edge Output The following procedure demonstrates how to manually deskew two oscilloscope channels and cables using the fast edge output, with no need for any T connector or adapters. It can be done once the temperature of the oscilloscope is stable. Note: This procedure only applies to the oscilloscope and cables connected directly to oscilloscope channels. Fast Edge output is available only on some models. If your oscilloscope does not have Fast Edge output, see Cable Deskewing Without the Fast Edge Output. The oscilloscope must be warmed for at least 20 min. before proceeding. The procedure should be repeated if the temperature of the oscilloscope changes by more than a few degrees. For the purpose of this procedure, the two channels are referred to as Channel X and Channel Y. The reference channel is Channel X, and the deskewed channel is Channel Y.

1. Begin by recalling the Default Oscilloscope Setup. 2. Configure the oscilloscope as follows:

• Timebase i. Fixed Sample Rate ii. Set the Sample Rate to 40 GS/s iii. Set the Time/Division to 1 ns/div

• Channels i. Turn on Channel X and Channel Y. ii. Set V/div for Channel X and Channel Y to 100mV/div. iii. Set the Averaging of Channel X and Channel Y to 500 sweeps. iv. Set the Interpolation of Channel X and Channel Y to Sinx/x.


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• Trigger i. Configure to Source to be FastEdge. ii. Set the Slope to Positive.

• Parameter Measurements: i. Set the source for P1 to CX and the measure to Delay. ii. Set the source for P2 to CY and the measure to Delay. iii. Set the source for P3 to M1 and the measure to Delay.

3. Set the display to Single Grid.

• Click Display Single Grid. 4. Using the appropriate adapter, connect Channel X to the Fast Edge Output of the oscilloscope. 5. Adjust the Trigger Delay so that the Channel X signal crosses at the center of the screen. 6. Change the Timebase to 50 ps/div.

7. Fine tune the Trigger Delay so that the Channel X signal crosses at the exact center of the screen.

8. Press the Clear Sweeps button on the front panel to reset the averaging. 9. Allow multiple acquisitions to occur until the waveform is stable on the screen.

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10. Save Channel X to M1.

• Click File Save Waveform.

• Set Save To Memory.

• Set the Source to CX.

• Set the Destination to M1.

• Click Save Now.

11. Disconnect Channel X from the Fast Edge Output and connect Channel Y to the Fast Edge Output.

12. Press the Clear Sweeps button on the front panel to reset the averaging.

13. Allow multiple acquisitions to occur until the waveform is stable on the screen. 14. From the Channel Y menu, adjust the Deskew of Channel Y until Channel Y is directly over the

M1 trace. 15. Ensure that P3 and P2 are reasonably close to the same value. (Typically < 5ps difference)


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Cable Deskewing Without the Fast Edge Output The following procedure demonstrates how to manually deskew two oscilloscope channels and cables using the differential data signal, with no need for any T connector or adapters. Note: This procedure only applies to the oscilloscope and cables connected directly to oscilloscope channels. Warm the oscilloscope for at least a half-hour before proceeding. This procedure should be run again if the temperature of the oscilloscope changes by more than a few degrees.

1. Connect a differential data signal to C1 and C2 using two approximately matching cables. Set up the oscilloscope to use the maximum sample rate. Set the timebase for a few repetitions of the pattern (at least a few dozen edges).

2. On the C3 menu, check Invert. Now C1 and C2 should look the same. 3. Using the Measure Setup, set P1 to measure the Skew of C1, C2. Turn on Statistics (Measure

menu). Write down the mean skew value after it stabilizes. This mean skew value is the addition of Data skew + cable skew + channel skew.

4. Swap the cable connections on the Data source side (on the test fixture), and then press the Clear Sweeps button on the oscilloscope (to clear the accumulated statistics; since we changed the input).

5. Write down the mean skew value after it stabilizes. This mean skew value is the addition of (-Data skew) + cable skew + channel skew.

6. Add the two mean skew values and divide the sum in half: UU [cable skew + channel skew]

2 7. Set the resulting value as the Deskew value in C1 menu. 8. Restore the cable connections to their Step 1 settings (previous). Press the Clear Sweeps

button on the oscilloscope. The mean skew value should be approximately zero - that is the data skew. Typically, results are <1ps given a test fixture meant to minimize skew on the differential pair.

9. On the C2 menu, clear the Invert checkbox and turn off the parameters.

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In the previous procedure, we used the default setup of the Skew parameter (which is detecting positive edges on both signals at 50%). We also inverted C2 in order to make C1 and C2 both have positive edges at the same time. Alternately, we clearly could have not inverted C2 and instead selected the Skew clock 2 tab in the P1 parameter menu and set the oscilloscope to look for negative edges on the second input (C2). However, we believe that the previous procedure looks much more aesthetically pleasing from the display as it shows C2 and C3 with the same polarity.