QPHY-SFI. Instruction Manual

Transcription

1 QPHY-SFI SFI Serial Data Compliance Software Instruction Manual Revision C November, 2017 Relating to: XStreamDSO v.8.5.x.x and later QualiPHY v.8.5.x.x and later

2 700 Chestnut Ridge Road Chestnut Ridge, NY, Tel: (845) , Fax: (845) 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 Rev C November, 2017

3 Table of Contents QPHY-SFI Instruction Manual Introduction... 1 About QualiPHY... 1 About QPHY-SFI... 1 Required Equipment... 1 Remote Host Computer System Requirements... 2 Installation and Setup... 3 Install Base Application... 3 Activate Components... 3 Set Up Dual Monitor Display... 3 Set Up Remote Control... 4 Configure Oscilloscope for Remote Control... 4 Add Connection to QualiPHY... 4 Select Connection... 4 Install MATLAB... 4 Using QualiPHY... 5 Accessing the Software... 5 General Setup... 6 Connection tab... 6 Session Info tab... 6 Report tab... 6 Advanced tab... 6 About tab... 6 QualiPHY Test Process... 7 Set Up Test Session... 7 Run Tests... 8 Generate Reports... 9 Customizing QualiPHY Copy Configuration Select Tests Edit Variables Edit Test Limits X-Replay Mode QPHY-SFI Testing Installing MATLAB Setting Up SDA Signal Input/Signal Dialog Clock Recovery/Clock Dialog Configuring 802.3ba Jitter Parameters J2 and J DDPWS TWDP QPHY-SFI Test Configurations DEMO Limiting Module Rx Out at C Host Tx Out at B Tests Limiting Module Rx Out at C Tests QPHY-SFI Test Descriptions Rise/Fall Times Transmitter Signal to Noise (Qsq) DDJ and DDPWS Uncorrelated Jitter Total Jitter (Host) Total Jitter & J2 (Module) Eye Mask Compliance Test Rev C i

4 QPHY-SFI Variables Acquire Live Data Demo Mode Save Waveform Path Scope Input Row Signal Source N Signal Source P QPHY-SFI Limit Sets Default Host Tx at B / Module Tx at B Lim. Mod. Rx Out at C / Host Rx Lim. Mod at C Appendix A: Manual Deskewing Procedures Cable Deskewing Using the Fast Edge Output Cable Deskewing Without Using the Fast Edge Output Table of Figures Figure 1. QualiPHY framework dialog and Standard selection menu... 5 Figure 2. Example of pop-up connection diagram and dialog box... 8 Figure 3. The Test Report Cover and Summary Table pages... 9 Figure 4. Configuration Test Selector tab Figure 5. X-Replay Mode window Figure 6. SDA Jitter Measure setup 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-SFI software option. Some of the images in this manual may show QualiPHY products other than QPHY-SFI, 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. ii

5 Introduction QPHY-SFI Instruction Manual About QualiPHY 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 help 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 help you understand device performance distribution, or obtain process related information from the devices under test. About QPHY-SFI QPHY-SFI is an automated test package performing all the normative, real-time oscilloscope tests for sources in accordance with the SFF8431 electrical specification. The software can be run on any Teledyne LeCroy oscilloscope with a bandwidth of 16 GHz or higher and 40 GS/s sample rate. Required Equipment Teledyne LeCroy real-time oscilloscope, 16 GHz BW, installed with o o o o XStreamDSO v minimum* with an activated QPHY-DP option key QualiPHY v minimum with an activated QPHY-DP component SDAII or SDAIII option (standard on SDA Zi and DDA Zi model oscilloscopes) MATLAB or MATLAB Component Run-time and IEEE file TWDP802_3clause68.m *Note: The versions 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 software may be installed on a remote PC, but all other software must be run on the oscilloscope. Optical or electrical cable as needed to deliver data to your module Test fixture (e.g., MAXIM HFRD-30.1 SFP+ HOST BOARD or similar available from Timbercon) Rev C 1

6 Remote Host Computer System 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 o Windows 10 Professional Windows 7 Professional 1 GHz or faster processor 1 GB (32-bit) or 2 GB (64-bit) of RAM Ethernet (LAN) network capability Hard Drive: o o At least 200 MB free to install the framework application 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. 2

7 Installation and Setup QPHY-SFI Instruction Manual 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 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 for instructions on setting up dual monitor display Rev C 3

8 Set Up Remote Control QualiPHY software can be executed from a remote host computer, controlling the oscilloscope through a LAN Connection: The oscilloscope must be connected to the LAN and assigned an IP address (fixed or dynamic). The host computer must be accessible to the oscilloscope. Configure Oscilloscope for Remote Control 1. From the menu bar, choose Utilities Utilities Setup 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 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. Install MATLAB The QPHY-SFI script requires a base installation of MATLAB and various MATLAB script files for jitter parameter calculations. See Installing MATLAB for download and installation instructions. 4

9 Using QualiPHY QPHY-SFI Instruction Manual This section provides an overview of the QualiPHY user interface and general procedures. For detailed information about the QPHY-SFI software option, see QPHY-SFI 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 subdialog. The subdialogs 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 1. QualiPHY framework dialog and Standard selection menu Rev C 5

10 General Setup The first subdialog 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 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. Do not use embedded spaces; use underscores, if necessary. Note: The software autogenerates the report file <Output file name>_<dut Name>, or LeCroyReport_<DUT> if you leave the defaults. This report is overwritten each session unless you specify a) a new DUT on the Session Info tab, b) a new output file name on the Report tab, or c) a new output file name in the Report Generator. Report tab Settings related to automatic report generation. Choose: Reporting behavior of: o o o Ask to generate a report after tests, where you ll be prompted to create a new file for each set of test results. Never generate a report after tests, where you ll need to manually execute the Report Generator to create a report. Always generate a report after tests, to autogenerate a report of the latest test results. Default report output type of XML, HTML, or PDF. Enter an Output file name, including the full path if you wish to change the output directory. The value in DUT will be appended to this file name. 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 allows you to manually generate a report using the last test session results. Advanced tab This tab launches the X-Replay Mode dialog. See X-Replay Mode. About tab Information about your QualiPHY installation. 6

11 QPHY-SFI Instruction Manual 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-SFI 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-SFI 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 Rev C 7

12 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 Figure 2. Example of pop-up connection diagram and dialog box 8

13 QPHY-SFI Instruction Manual 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. 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. Figure 3. The Test Report Cover and Summary Table pages Rev C 9

14 Customizing QualiPHY The pre-loaded configurations cannot be modified. However, you can create your own test configurations by copying one of the standard test configurations and modifying it. 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. 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: If any part of a configuration is changed, the Save As button becomes active on the bottom of the dialog. If a custom configuration is changed, the Save button will also become active to apply the changes to the existing configuration, rather than create a new one. 10

15 QPHY-SFI Instruction Manual Select Tests On the Test Selector tab, check the tests that make up the configuration. Each test is defined by the DisplayPort standard. A description of each test is displayed when it is selected. To loop any of the tests in this configuration, select the test from the list, then choose to Loop selected test until stopped or enter the number of repetitions. When defining a number of repetitions, enter the number of repetitions before selecting the checkbox. Figure 4. Configuration Test Selector tab Rev C 11

16 Edit Variables The Variable Setup tab contains a list of test variables. See QPHY-SFI Variables for a description of each. To modify a variable: 1. Select the variable on the Variable Setup tab, then click Edit Variable. 2. The conditions of this variable appear on a pop-up. Choose the new condition to apply. You can also choose to Reset to Default at any time. 12

17 QPHY-SFI Instruction Manual 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 Rev C 13

18 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 MIPI M-PHY 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. Figure 5. X-Replay Mode window 14

19 QPHY-SFI Instruction Manual QPHY-SFI Testing Before beginning any data acquisition or test, warm the oscilloscope for at least 20 minutes. Teledyne LeCroy oscilloscopes automatically perform a brief self-calibration routine as needed to maintain accuracy. No user intervention is required. This procedure will be run again if the temperature of the oscilloscope changes by more than a few degrees. Installing MATLAB If your instrument does not already have MATLAB installed, download and install the MATLAB Component Run-time v. 7.7 or later. Once installed, the MCR will execute automatically when the oscilloscope is started. It must remain running while you are using QualiPHY for the test scripts to function properly. A copy of the free software and instructions for installing it are available from: You will also need to install the TWDP calculation MATLAB script file (TWDP802_3clause68.m). A copy of the TWDP script file can be downloaded from: An explanation of what the TWDP script computes, written by the script s authors, is available from: For more instructions on installing the files and configuring the measurements within the SDA application, see Configuring 802.3ba Jitter Parameters. Setting Up SDA SDA must be configured to analyze the Gb/s data stream. On the Serial Data Analysis/SDA dialog, make sure Enable SDA is checked. We recommend the following settings for the remainder of the dialogs: Signal Input/Signal Dialog Select the appropriate input(s). Set Level, Percent, 50%. Set Signal Type, Custom. You should also be able to set the level to Absolute, 0mV. Specifying a slightly incorrect threshold level will cause noticeable increases in J2 and J9 and may affect TWDP, but it will not affect DDPWS because that parameter computes its own threshold, at the mean of the waveform, as required by the 802.3ba specification. Clock Recovery/Clock Dialog The signals are at a very stable bit rate, so a single pole FC Golden PLL is all that is required to recover the clock. It is important to press Find Rate. Starting at a slightly wrong frequency can cause slight differences in the parameters Rev C 15

20 Configuring 802.3ba Jitter Parameters Several jitter parameters defined by the IEEE 802.3ba specification are applied to the signal via the SDA application as part of the overall QualiPHY test procedure. J2 and J9, as described in 802.3ba clause DDPWS, as described in 802.3ba clause 86A TWDP, as described in clause These parameters can be found on the SDA Jitter Measure 802.3ba subdialog (SDAII shown here). Figure 6. SDA Jitter Measure setup Note: Be sure to check Enable Jitter Meas., then click Jitter Parameters to display the dialogs. The following sections provide details on using each of these parameters. Only the TWDP parameter requires some special setup; the other three should simply work when turned on. Note: See Installing MATLAB for instructions on downloading the required MATLAB calculation file. 16

21 J2 and J9 J2 and J9 are derived from Q-scale fit on the jitter distribution. QPHY-SFI Instruction Manual J2 and J9 are supposed to be computed from a signal that is either PRBS31, scrambled idle (defined in 802.3ba clause as 64b/66b encoded PRBS31), or, for J2 only, a valid 40GBASE-SR4 or 100GBASE-SR10 signal. PRBS31 is so long (over 208ms) that it must be treated as non-repeating, and a real signal that is scrambled is also treated as non-repeating. The only setup required for J2 and J9 therefore is the general SDA setup for non-repeating signals: On the Jitter Measure/Jitter Dialog Touch Pattern Analysis and deselect Repeating Pattern. The Pattern Analysis indicator should show green. In the picture above, J2 and J9 were computed on a shorter repeating pattern. Note: Because the default jitter decomposition technique used in SDA is spectral, you may notice (as shown in the picture above) that Tj at 1e-12 may be slightly less than J9. On the Jitter Parameters Subdialog If you choose a Jitter Model of Dual Dirac NQ-Scale instead of Dual Dirac Spectral, the oscilloscope uses a similar (but not identical NQ-scale is normalized Q scale) fit to the one used by J2 and J9. The NQ-Scale fit sees somewhat more Rj, so the Tj at 1e-12 using NQ-Scale on the same waveform (as in the picture above) is ps, which agrees better with J9 of ps. The Jitter Model affects how the SDA separates Rj and Dj and therefore affects Tj. Because J2 and J9 use their own Q scale fit, changing the Jitter Model has no effect on J2 and J9. DDPWS DDPWS finds the narrowest pulse in an averaged repeating pattern, then it returns the difference between the nominal pulse width and the narrowest pulse width. According to 802.3ba, the pattern is supposed to be PRBS9. Our implementation of DDPWS automatically finds the repeating pattern, which makes it take slightly longer on the first sweep. On subsequent sweeps, it just verifies the pattern. DDPWS is a selfcontained computation; it is not affected by whether the SDA is in Repeating Pattern mode or not; nor by the Jitter Model discussed earlier; nor by the signal Level setting. DDPWS computes its threshold level as the mean of the averaged pattern waveform, as required by 802.3ba. There is a Find Pattern button on the 802.3ba subdialog that is connected to the Pattern Analysis dialog Find Pattern button. If Find Pattern is pressed, every computation that depends on the pattern will discard accumulated results and find the repeating pattern again. This affects both DDPWS and TWDP, and many of the SDA jitter parameters in Repeating Pattern mode (which is the default, but needs to be turned off for J2 and J9 measurement, as discussed above). Since DDPWS automatically finds the repeating pattern, and will discard accumulated results if the pattern changes, it should never be necessary to press Find Pattern to affect the DDPWS computation. DDPWS also responds to the Clear Sweeps button on the oscilloscope front panel and several touch screen dialogs (such as Measure Setup). Clear Sweeps causes every computation that accumulates results from multiple sweeps to discard accumulated results and restart ba says that the bandwidth required for DDPWS is 12GHz, and that a bandwidth above 12GHz is expected to have little effect on the results Rev C 17

22 TWDP TWDP is implemented as described in clause , using the Matlab script in clause and implemented in the file TWDP802_3clause68.m. We use the script exactly as distributed by IEEE. Because the script is copyrighted by IEEE we cannot distribute it. You must download and install the MATLAB file and the two text files included with it on the oscilloscope. We recommend D:\Applications\Enet, but any directory can be used. Specify the directory where the script is installed on the 802.3ba subdialog in the field labeled Path to TWDP802_3clause68.m. MATLAB (or at least the MCR) must be installed and running on the instrument to execute TWDP802_3clause68.m successfully. We verified that the script works with MATLAB R2010b. That completes the required setup. When the TWDP measurement checkbox is selected on the 802.3ba subdialog, it should be computed. The following section provides more detail about the use of the TWDP802_3clause68.m file by the SDA tool. TWDP802_3clause68.m The script has hardcoded the names of two files that it expects to open: The averaged pattern waveform with exactly 16 samples per UI The digital pattern as a list of 1 and 0. (The pattern should be PRBS9, which is 511 bits long, according to clause ) In order to use the script without modification, the oscilloscope creates those file on the disk, in the same directory as the script, and names them as the script requires; then it invokes the script, reads back the TWDP result produced by the script, and shows exactly that as a parameter result. This uses the oscilloscope s capability to run a MATLAB script to produce a parameter. SDA sets it up to run a small MATLAB script created within SDA that sets MATLAB s current directory to be the directory that contains the script and the input files, calls TWDP802_3clause68.m, and returns the result that it creates from the MATLAB variable TWDP. For reference, the MATLAB script created by the SDAII looks like this: % this is a custom parameter measurement that uses the TDP802_3clause68.m MATLAB CODE % (called below) %clear the command window clc %SDA2 adds cd to the directory specified by the user, where the files are [SUCCESS, MESSAGE, MESSAGEID] = movefile( 'sas2_symbol.txt', 'prbs9_950.txt','f'); [SUCCESS, MESSAGE, MESSAGEID] = movefile( 'sas2_waveformdata.txt', 'preproc txt', 'f'); if SUCCESS == 0 MESSAGE end 18

23 QPHY-SFI Instruction Manual %these are assumed values for the input function, hardcoded in TWDP802_3clause68.m %so really these are just for documentation here. SymbolRate= ; SamplesPerUI=16; TWDP802_3clause68 ParamOut=TWDP Note: The bit rate Gb/s is hardcoded inside TWDP802_3clause68.m. Although SDA will produce the required files at any bit rate, and TWDP will be computed, the computation of TWDP by TWDP802_3clause68.m assumes that the bit rate is Gb/s. When the oscilloscope is started, our MATLAB parameter processor launches MATLAB, and it holds information allowing it to invoke that instance of MATLAB. If you look for it, you will find a MATLAB Command Window open on the oscilloscope. Do not close the MATLAB Command Window. The TWDP computation must run its MATLAB script using that invocation of MATLAB. Caution: If you do close the MATLAB Command Window, the TWDP computation will fail (it will show ) until the oscilloscope is restarted Rev C 19

24 QPHY-SFI Test Configurations Test configurations include variable settings, limit sets, and test selections. See QPHY-SFI Variables for a description of each variable and its default value. See the QPHY-SFI Limit Sets for more information about the default test limits. DEMO Limiting Module Rx Out at C This configuration performs a demonstration of all tests covered in QualiPHY SFI pertaining to devices at test point C using stored waveforms. The limit set in use is SFF 8431specification limits. All variables are set to defaults, except that Test Mode is set to Use Saved Data, Saved Waveform Path is set to D:\Waveforms\SFI\Demo, and Demo Mode is set to Yes. The tests performed are: Rise 20% - 80% and Fall 80% - 20% DDPwS Total Jitter and J2 Jitter (99% Jitter) Eye Mask Hit Ratio Host Tx Out at B Tests This configuration generates the specification required measurements and eye diagram as described in section of SFF 8431 Rev 4.1. All variables are set defaults. The tests performed are: Rise 20% - 80% and Fall 80% - 20% Transmitter Signal to Noise (Qsq) DDJ and DDPwS Uncorrelated Jitter Total Jitter Eye Mask Hit Ratio Limiting Module Rx Out at C Tests This configuration generates the specification required measurements and eye diagram as described in section of SFF 8431 Rev 4.1. All variables are set to defaults. The tests performed are: Rise 20% - 80% and Fall 80% - 20% DDPwS Total Jitter and J2 Jitter (99% Jitter) Eye Mask Hit Ratio 20

25 QPHY-SFI Instruction Manual QPHY-SFI Test Descriptions These are the standard SFI compliance tests. Rise/Fall Times This test measures 20-80% rise and fall times using the VMA test pattern. For Hosts, rise/fall must be > 34 ps. For Modules, rise/fall must be > 28 ps. Note: The 96 ps upper limit is not defined by the standard, it is just a reasonableness test. This should never fail. Transmitter Signal to Noise (Qsq) This test measures noise amplitude relative to signal amplitude using the VMA test pattern to calculate Qsq.. Must be > 50. See Appendix D-8 of the SFF-8431 specification. DDJ and DDPWS This test uses PRBS-9 to measure Data Dependent Jitter (DDj) and Data Dependent Pulse Width Shrinkage (DDPWS). For Hosts, DDj must be less than 0.1 UI. DDPWS must be less than UI. For Modules, DDPWS must be less than 0.3 UI. DDj is not measured. Uncorrelated Jitter This test uses a PRBS-9 function to calculate Uncorrelated Jitter (Uj). Total Jitter (Host) This test uses PRBS-31 or 64B/66B encoded data to measure Total Jitter (Tj). For Hosts, Tj must be less than 0.28 UI. Total Jitter & J2 (Module) This test uses PRBS-31 or 64B/66B encoded data to measure Total Jitter (Tj) and J2, the 99% jitter (that is, jitter down to 1e-2 probability). This is meant to approximate Dj. At Module Rx, Tx must be less than 0.7UI. J2 must be less than 0.42 UI. Eye Mask Compliance Test This test uses PRBS-31 or 64B/66B encoded data to test the eye diagram against the Tx-Host mask. Eye masks are defined at the various compliance test points. The specification allows a ratio of mask hits to mask out of up to 50 ppm Rev C 21

26 QPHY-SFI Variables Acquire Live Data If this variable is set FALSE, (previously) stored waveforms are recalled and the tests are performed on them. If this variable is set to TRUE (and DemoMode is off) then new data will be acquired for each test. Demo Mode When set to ON, this variable allows you to run the tests in Demo Mode using saved waveforms located 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 their other variable selections. This allows the user to experience running the tests as they would be run on live signals. The default value is OFF. Save Waveform Path Full path to the root folder in which waveform files will be saved, or if Aquire Live Data is FALSE, the path from which previously stored waveforms will be read. Note: The DUT name is appended to this path when it is used. Therefore, the path must end with a backslash. For example: if Save Waveform Path is set to D:Waveforms\SFI\, then files will be saved in (or recalled from) D:Waveforms\SFI\[DUT]. Scope Input Row This variable allows you to specify the upper (A) or lower (B) input row of the oscilloscope. On most oscilloscopes, the A inputs are used. This variable allows use of the high bandwidth inputs in the B row of some Teledyne LeCroy oscilloscope models. Signal Source N Channel used for the negative lane of the differential input signal from point B on the Host Compliance board. Signal Source P Channel used for the positive lane of the differential input signal from point B on the Host Compliance board. 22

27 QPHY-SFI Instruction Manual QPHY-SFI Limit Sets The default installation of QPHY-SFI contains three limit sets: Default This set applies the limits specified in SFF8431 electrical specification. Host Tx at B / Module Tx at B Limits defined for Host Tx Out at B Tests configuration. Also to be used for Module Tx Out at B tests. Lim. Mod. Rx Out at C / Host Rx Lim. Mod at C Limits defined for the Limiting Module Rx Out at C Tests configuration. Also to be used for Host Rx Limiting Module at C tests Rev C 23

28 Appendix A: Manual Deskewing Procedures This section is only applicable to the oscilloscope and the cables connecting to the oscilloscope channels. Note that the cables connecting the PeRT3 to the fixture or to the DUT must be phase matched within a tight tolerance because the PeRT, like any generator, does not have the capability to compensate for mismatched cables connected to its outputs. 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. This can be done once the temperature of the oscilloscope is stable. The oscilloscope must be warmed up 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. For the purpose of this procedure, the two channels being deskewed are referred to as Channel X and Channel Y. The reference channel is Channel X and the channel being deskewed 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. 24

29 QPHY-SFI Instruction Manual 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 Rev C 25

30 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) 26

31 UU QPHY-SFI Instruction Manual Cable Deskewing Without Using 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. This can be done once the temperature of the oscilloscope is stable. The oscilloscope must be warmed up 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: [Data skew + cable skew + channel skew] + [ (-Data skew) + cable skew + channel skew]uu 2 The above formula simplifies to: [cable skew + channel skew] 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 Rev C 27

32 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. 28

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