Developing Customized Measurements and Automated Analysis Routines using MATLAB

Transcription

1 2013 The MathWorks, Inc. Developing Customized Measurements and Automated Analysis Routines using MATLAB Guillaume Millot MathWorks France

2 MathWorks Overview Founded in 1984 in the US Several software platforms : MATLAB Headquarters in Boston Offices throughout Europe including France, Germany, and the United Kingdom Used by more than 1,000,000 users in over 175 countries Used in over 3,500 universities 2

3 MATLAB The leading environment for technical computing Technical computing language Development environment More than 1500 functions Math 2D, 3D graphics and GUI design File I/O Calling C/C++, Fortran, Java, COM Toolboxes for signal and image processing, connection to hardware or databases, statistics, optimization, Available from MathWorks or Agilent with Infiniium and InfiniiVision oscilloscopes and other instruments 3

4 Technical Computing Workflow Access Files Explore & Discover Data Analysis & Modeling Share Reporting and Documentation Software Algorithm Development Outputs for Design Code & Applications Hardware Application Development Deployment Automate 4

5 Measurement, analysis, and testing challenges for high speed serial and other systems 1. Creating analysis and measurement routines for designing and testing your system 2. Interfacing and verifying these routines with live measured data 3. Visualizing analysis routines to improve signal integrity 5

6 Measurement, analysis, and testing challenges for high speed serial and other systems 1. Creating analysis and measurement routines for designing and testing your system 2. Interfacing and verifying these routines with live measured data 3. Visualizing analysis routines to improve signal integrity 6

7 Example: Developing an analysis routine to perform device characterization Goals: 1. Characterize the unknown device (it will be a low-pass filter) 2. Analyze the device (in this case the low-pass filter) to determine if it behaves as designed 1 0? In V+ V R Transfer Function: C T V+ V- j Out In Out 1 1 j CR Cutoff Frequency: 1 F o 2 CR 7 7

8 System Input Device Characterization Interactively develop your transfer function and analysis routines V+ V- R = 1kW V+ C =.1mF V- Response Agilent Oscilloscope T j 1 1 o CR 1 j CR Agilent Signal Generator GPIB, LAN, or USB MATLAB 8 8

9 Device Characterization Ideal end result Circuit to be characterized Automated Circuit Tool application developed in MATLAB to characterize the circuit and determine if it behaves as designed 9

10 Demo Clip 10

11 Device Characterization Develop and Deploy Application Create custom graphical user interface to encapsulate/automate your MATLAB analysis routine for others to use 11

12 Measurement, analysis, and testing challenges for high speed serial and other systems 1. Creating analysis and measurement routines for designing and testing your system 2. Interfacing and verifying these routines with live measured data 3. Visualizing analysis routines to improve signal integrity 12

13 MATLAB Connects to Your Hardware Devices Instrument Control Toolbox Instruments and RS-232 serial devices Data Acquisition Toolbox Plug-in data acquisition devices and sound cards Image Acquisition Toolbox Image capture devices Vehicle Network Toolbox CAN bus devices using CAN and XCP protocols MATLAB Interfaces for communicating with everything 13

14 Creating a pre-distortion filter and verifying it with live Agilent oscilloscope signals Task Improve system BER Solution Characterize system s response Use the characterization to develop pre-distortion filter 14

15 Step 1: Waveform acquisition from Agilent Oscilloscope Use Test & Measurement Tool on or off the scope Test & Measurement Tool provided with MATLAB s Instrument Control Toolbox 15

16 Amplitude (AU) Amplitude (AU) Voltage Voltage Step 2: Use acquired signals to design pre-distortion filter With thumb In-phase Signal Time x Sans thumb In-phase Signal Time x Time (s) x Time (s) x Use system identification functions to design FIR pre-distortion filter 16

17 Step 3: Execute your analysis routines directly on an Agilent oscilloscope Agilent and MathWorks teamed up to create a custom development environment using Infiniium oscilloscopes and MATLAB to address unique and special measurement needs. Requires no knowledge of MATLAB to operate on the scope Agilent automatically includes the MATLAB software environment as part of the N8806A UDF option

18 Measurement, analysis, and testing challenges for high speed serial and other systems 1. Creating analysis and measurement routines for designing and testing your system 2. Interfacing and verifying these routines with live measured data 3. Visualizing analysis routines to improve signal integrity 18

19 Visualizing MATLAB analysis routines to improve signal integrity High-speed digital signals are susceptible to signal integrity issues due to limitations of the physical interface. You need: 1. Analysis routines to analyse backplane behaviour. 2. Acquire live signals from Agilent instruments to create and verify these analysis routines. 3. Applications to automate the execution of these measurement and analysis routines. MATLAB provides the capabilities to create analysis routines, interface to Agilent instruments to acquire live signals to verify them, and language and tools to automate the execution

20 MATLAB Code for Acquiring Live Signals from Agilent instruments %% Directly acquire digital signals from Agilent oscilloscope or S-Parameters from Agilent network analyzer... %% Convert the 16-Port to 4-Port S-Parameters SingleEnded4PortSParams = snp2smp(singleended16portdata.s_parameters, SingleEnded16PortData.Z0, [ ]); %% Convert 4-Port to 2-Port Differential S-Parameters Differential2PortSparamsForChannel = s2sdd(singleended4portsparams); %% Calculate the Frequency Response DifferentialFreqResponseForChannel = s2tf(differential2portsparamsforchannel); %% Fit Differential Frequency Response to Rational Function ModelforForwardChannel = rationalfit(freq, DifferentialFreqResponseForChannel);... 20

21 MATLAB Code for Visualizing Jitter of Acquired Signals %% First Input and its Output due to CrossTalk InputSignal_1 = GenerateInputsignal(TotalSampleNumber, ); OutputSignal_1 = timeresp(modelforcrosstalk_1, InputSignal_1, ); %% Second Input and its Output (forward channel) InputSignal_2 = GenerateInputsignal(TotalSampleNumber, ); OutputSignal_2 = timeresp(modelforforwardchannel,inputsignal_2, );... %% The Output Signal of the Second Channel OutputSignal = OutputSignal_1 + OutputSignal_2 + OutputSignal_3 + OutputSignal_4; %% Eye Diagram of the Output Signal EyeDiagram = commscope.eyediagram('samplingfrequency', 1./SampleTime, 'SamplesPerSymbol', OverSamplingFactor) update(eyediagram, OutputSignal); %% Jitter Measurements analyze(eyediagram); Measurements = EyeDiagram.Measurements 21

22 Visualizing of Eye Diagram Characteristics in MATLAB Total jitter: deterministic jitter and random jitter 22

23 Visualizing of Eye Diagram Characteristics in MATLAB (continued) Deterministic jitter only, no random jitter 23

24 Measurement, Analysis, and Testing Challenges Creating analysis and measurement routines for designing and testing your system MATLAB is a software environment and a programming language made for design and test engineers to be productive Supports analysis routine creation, data visualization, and application development Interfacing and verifying these routines with live measured data Integrated measurement and analysis provided with MATLAB Ability to execute your MATLAB analysis routines directly on Agilent oscilloscopes using N8806A UDF Visualizing analysis routines to improve signal integrity Analysis routines created in MATLAB can be utilized to visualize and understand eye diagram characteristics to help improve signal integrity of your high-speed systems 24

25 Agilent and MATLAB Resources for Developing Customized Measurement and Analysis Routines MATLAB overview: Instrument Control Toolbox overview: Signal Processing Toolbox overview: Agilent resource page on MATLAB for Agilent Infiniium and InfiniiVision scopes: Agilent resource page on MATLAB with Agilent instruments: Agilent N8806A User Defined Function: Using MATLAB to control Agilent oscilloscopes, function generators, and other instruments 25

26 EXTRA SLIDES 26

27 Device Characterization Step 1: Stimulate device and acquire device responses Configure Agilent signal generator and Agilent oscilloscope with Instrument Control Toolbox 27

28 Device Characterization Step 2: Visualize Data Plot data Select data to plot in the Workspace Browser Select desired plot type from the Plot button The equivalent command is displayed in the Command Window 28

29 Device Characterization Step 3: Pre-process Data Scale the data Interactively zoom to explore data identify scaling problem Correct scaling with simple MATLAB command 29

30 Device Characterization Step 4: Visualize Original and Processed Data Build custom visualization with Plot Tools Enable Plot Tools (plottools) with button on Figure Toolbar Drag and drop to layout axes and add data to plots Customize and annotate plots Automatically generate MATLAB code to reproduce visualization with new data 30

31 Device Characterization Step 5: Estimate Transfer Function Estimate Transfer Function with the Signal Processing Toolbox Search the Help for desired functionality Run sample code directly from the Help Browser Modify commands for our data 31

32 Device Characterization Step 6: Compare with Expected Results Compute expected response with governing equations Fit theoretical response to measured response with the Curve Fitting Toolbox Use Curve Fitting Tool to interactively design and analyze a fit to our data Automatically generate MATLAB code to compute fit with new data 32

33 Device Characterization Step 7: Automate Repetition of Analysis Write custom script to automate workflow Create MATLAB file from selected commands in Command History Add comments to generated code in Editor Use %% to divide code into individual cells to improve readability and support cell execution 33

34 Device Characterization Step 8: Publish Results Publish MATLAB file directly to HTML document Click Publish to HTML button in Editor Toolbar Each cell is converted to a section of the document All code, comments, and output are captured in the document 34

35 Instrument Control Toolbox Enables MATLAB to configure, control, and transfer data with instruments such as oscilloscopes, pulse generators, and signal analyzers Integrate instruments into MATLAB applications and Simulink Interactive tool for detecting and controlling instruments Automatic code generation for faster and easier implementation Support for IVI, VXIplug&play, and MATLAB instrument drivers Support for common communication protocols 35

36 Instrument Control Toolbox and N8806A User Defined Function Instrument Control Toolbox Use MATLAB to control the oscilloscope, either on or off the scope, to automate measurements Download data directly into MATLAB for analysis and to build complete GUI-based test applications. User Defined Function Use MATLAB directly on Infiniium oscilloscopes to make customized measurements. 36

37 N8806A User Defined Function How to Access In Analyze pull down menu, click Math Then select your new function from the Operator pull down list 37 37