MicronPresentationppt.ppt

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1、,Micron Engineering Clinic,Fall 08 Spring 09,Welcome toMicron Engineering ClinicAnalysis and Optimization of Multi Gb/s Chip-to-Chip Communication,Micron Engineering Clinic,Fall 08 Spring 09,Team Members Documentation Lead Raheem Alhamdani-CE Technical Leads Bryson Kent-EEJordan Kemp-EELucas Loero-E

2、ETeam LeadBen Meakin CE,Micron Engineering Clinic,Fall 08 Spring 09,Introduction and Motivation for Modeling and Verification of Interconnects,Raheem AlhamdaniDocumentation LeadComputer EngineerAlhamdaneng.utah.edu,Micron Engineering Clinic,Fall 08 Spring 09,Introduction,The Sponsor:Manufacturer of

3、DRAM,Flash Memory,and Image Sensor Integrated Circuits,What Have They Asked Us To Do?Design a software application for modeling and verification of chip-to-chip interconnects,Micron Engineering Clinic,Fall 08 Spring 09,Introduction,What is Verification?Proving through tests and formal methods that a

4、 design does what it is intended to do,What are Chip-to-Chip Interconnects?Electrical systems for communication between two integrated circuits,Micron Engineering Clinic,Fall 08 Spring 09,Motivation,BackgroundMemory and I/O Devices Operate Much Slower than CPUAccess to Off-Chip Resources is Expensiv

5、e 300 cycles-Usually Cycles are WastedDemand for Low-Power yet High-Performance-Cant Have Wasted Cycles!Goal:Speed Up Devices and Speed Up Interconnect,Micron Engineering Clinic,Fall 08 Spring 09,As Devices Move Towards Being Smaller,Faster,Lower PowerInterconnects Become Slower,Noisier,and Unreliab

6、leIssues:Inter-Symbol Interference(ISI)Co-Channel InterferenceTiming JitterVoltage Noise,Problem,Conventional Testing Methodologies are not Feasible or Sufficient,Micron Engineering Clinic,Fall 08 Spring 09,Eye Diagram,Voltage,Time,What is an eye diagram?A useful tool for the qualitative analysis of

7、 signal used in digital transmission.,Micron Engineering Clinic,Fall 08 Spring 09,Eye Diagram,Time,Voltage,Voltage,Time,BitsSuperimposed1 Unit Interval(UI),How is it created?,Micron Engineering Clinic,Fall 08 Spring 09,Eye Diagram(Noise),Time,Voltage,Voltage,Time,BitsSuperimposed1 Unit Interval(UI),

8、Bit-stream,Voltage Noise,What Causes Noise?Interference from neighboring wires(Co-Channel Interference)Electromagnetic InterferenceLink resistance,capacitance,and inductance,Micron Engineering Clinic,Fall 08 Spring 09,Eye Diagram(Jitter),Time,Voltage,Voltage,Time,BitsSuperimposed1 Unit Interval(UI),

9、Bit-stream,Jitter,What Causes Jitter?Clock Variation(Skew)Reflection General Timing Uncertainty,Micron Engineering Clinic,Fall 08 Spring 09,Real Eye Diagram,Data Jitter,Clock Jitter,Signal Noise,Vref,Data SignalClock Signal,Vref Noise+ReceiverSensitivity,How to interpret it?,Micron Engineering Clini

10、c,Fall 08 Spring 09,Solution,Our Objective is Not to Solve These Problems Through Better Design,but toProvide Designers with a Tool That Correctly Models and Verifies Interconnects With These Problems,Deliverables:Cross Platform App with Graphical User InterfaceProvide Worst-Case and Statistical Bas

11、ed Link AnalysisSpice CompatibleCorrectly Model Co-Channel Interference and Tx/Rx Jitter,Micron Engineering Clinic,Fall 08 Spring 09,Project DocumentationMeeting minutes,Time-line,Progress Report,Presentations,Proposal and links are all on the teams website:www.eng.utah.edu/alhamdan/Micron/Micron.ht

12、ml,My Roles,Graphical User Interface and Software DevelopmentGUISoftware skeletonPlotting code Code documentation,Micron Engineering Clinic,Fall 08 Spring 09,Teams website,Micron Engineering Clinic,Fall 08 Spring 09,Meeting Minutes,Micron Engineering Clinic,Fall 08 Spring 09,Bibliography,B.K.Casper,

13、M.Haycock,and R.Mooney,“An accurate and efficient analysis method for multi-Gb/s chip-to-chip signaling scheme”,in Digest of Technical Papers from the IEEE Symposium on VLSI Circuits,June 2002,pp.5457.B.K.Casper,G.Balamurugan,J.E.Jaussi,J.Kennedy,M.Mansuri,“Future microprocessor interfaces:Analysis,

14、design and optimization”,in Proceedings of the IEEE Custom Integrated Circuits Conference,Sept.2007,pp.479-486.P.K.Hanumolu,B.K.Casper,R.Mooney,G.Y.Wei,and U.K.Moon,“Jitter in high-speed serial and parallel links”,in Proceedings of the IEEE International Symposium on Circuits and Systems,May 2004,pp

15、.425428.Pavan Kumar Hanumolu,Bryan Casper,Randy Mooney,Gu-Yeon Wei,and Un-Ku Moon,“Analysis of PLL Clock Jitter in High-Speed Serial Links”,in IEEE Transactions on Circuits and Systems,November 2003,pp.879-886,Micron Engineering Clinic,Fall 08 Spring 09,Questions?,Micron Engineering Clinic,Fall 08 S

16、pring 09,Worst Case Verification of High Speed Interconnects,Bryson KentTechnical LeadElectrical EngineerB,Micron Engineering Clinic,Fall 08 Spring 09,Introduction,What is Worst Case analysisWhy is the Worst Case importantHow to calculate the Worst CaseWhat are the resultsConclusion and implementati

17、on,Micron Engineering Clinic,Fall 08 Spring 09,Worst Case Analysis,Summation of all negative effectsGood representation of what can happen if certain conditions ariseVerification of error free transmission Classic analysis of 1 trillion bits(1*1012 bits)*(10-6sec)=over 10 days,Micron Engineering Cli

18、nic,Fall 08 Spring 09,Worst Case Eye Diagram,WC1 WC2 WC3,Voltage Vs one period of timeDistortion sources add to close the eyeFrom the eye diagram we can calculate a system pass fail,Tim Hollis,Micron Senior Project Proposal,Pass/Fail,Micron Engineering Clinic,Fall 08 Spring 09,Inter-Symbol Interfere

19、nce,Inter-Symbol interference is the main source of interferenceData dependent jitter and Co-channel interference add to signal degradation,Tim Hollis,Micron Senior Project Proposal,Micron Engineering Clinic,Fall 08 Spring 09,C(t)=transmitter symbol responseP(t)=impulse response of the channel,Worst

20、-Case Computation,Worst case eye diagram due to Inter-symbol interference,Worst case eye diagram due to Inter-symbol interference and cochannel interference,J.G.Proakis,“Digital Communication”,McGraw-Hill,3rd Ed.,1995.B.K.Casper,M.Haycock,and R.Mooney,“An accurate and efficient analysis method for m

21、ulti-Gb/s chip-to-chip signaling schemes”,in Digest of Technical Papers from the IEEE Symposium on VLSI Circuits,June 2002,pp.5457.,Micron Engineering Clinic,Fall 08 Spring 09,Calculating the eye diagram,Tim Hollis,Micron Senior Project Proposal,Micron Engineering Clinic,Fall 08 Spring 09,Results,Ca

22、lculated performance Vs given performance,Micron Engineering Clinic,Fall 08 Spring 09,Conclusion,Worst case analysis is beneficialComputation is pulse based analysisUser can define and add any distortion as desiredResults of worst case analysis match results of given test case,Micron Engineering Cli

23、nic,Fall 08 Spring 09,Questions?,Micron Engineering Clinic,Fall 08 Spring 09,Statistical Analysis ofElectrical Signaling,Jordan KempTechnical LeadElectrical E,Micron Engineering Clinic,Fall 08 Spring 09,Introduction,How,Why,What,Summary,Micron Engineering Clinic,Fall 08 Spring 09,Introduction,Worst

24、Case Eye good for Pass/Fail Mask,but doesnt give details,Need for probability of error,rather than rigid“Pass/Fail”,Pass/Fail Mask,Micron Engineering Clinic,Fall 08 Spring 09,Use channel impulse response,p(t),and transmitter symbol response,c(t),Introduction,Find PDF(Probability Density Function)&CD

25、F(Cumulative Distribution Function)of the channel output,Micron Engineering Clinic,Fall 08 Spring 09,Introduction,Shows BER of transmitted data given timing uncertainty(data jitter,clock jitter)and voltage uncertainty(VREF,Rx sensitivity,ISI),Plot BER eye-diagram as a function of sample time,sample

26、voltage,and probability of error,Micron Engineering Clinic,Fall 08 Spring 09,Why,Trends Increase:Speed,Capacity Decrease:Form-Factor,Power,Cost All above decrease Signal Integrity,Theoretically impossible to send error-free data,Bit Error Rate(BER)=,Micron Engineering Clinic,Fall 08 Spring 09,What,P

27、robabilistic data eye using channel impulse response,p(t),and transmitter symbol response,c(t)to find the PDF&CDF of the channel output,What is a PDF?-Probability Density Function-Shows the probability that a specific value is likely to happen-Integrates to 1,What is a CDF?-Cumulative Distribution F

28、unction-Shows the probability is less than or equal to a specific value-Integral of the PDF,Micron Engineering Clinic,Fall 08 Spring 09,How(1),1st Way(from*Casper paper):,Recursively convolve 1UI sample terms assuming equal probability of a transmitted 0 or 1,0-0.01 0 0.590-0.070 0.0150 0.0550 0.20

29、0.50 00 0.7,(Each step scaled by to account for P(0)=P(1),0.59,0.0,1UI,y(t),Micron Engineering Clinic,Fall 08 Spring 09,How(1),VERY hardware intensive(must compute multiple convolutions)Must maintain certain amount of resolution,slowing computations down even more Very quickly run out of memory perf

30、orming calculations,Problems:,0-0.01 0 0.59 0-0.07 0 0.015 0 0.055 0 0.2 0 0.5 0 0.,1.452 1(no decimal resolution)1.452 1.4(one decimal resolution)1.452 1.45(two decimal resolution),delta function 1:0 1 0 0 1 2.delta function 1.4:0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0.1.2.3.4.5.6.7.8.9 1 1.1 1.2 1.3 1.4

31、1.5.,Micron Engineering Clinic,Fall 08 Spring 09,How(2),Implemented Method(modified from previous):,0-0.01+0 0.59+0-0.07+0 0.015+0 0.055+0 0.2+0 0.5+0 0+0 0.7,Same points taken as before,but add instead of convolve Keeps track of locations of delta functions Keeps track of heights of each delta Plot

32、 locations versus heights,Micron Engineering Clinic,Fall 08 Spring 09,How(2),-.01,0,Height=0.5,0,.59,Height=0.5,Height=0.25,-.01 0,.58.59,0-0.01 0 0.59=0-.01(0+.59)(-.01+.59)=-.01 0.58.59 Instead of convolving,proposed method adds&concatenates,Micron Engineering Clinic,Fall 08 Spring 09,Advantages:,

33、VERY quick Easy to implement Infinite precision(in theory),How(2),Micron Engineering Clinic,Fall 08 Spring 09,Summary,Use channel impulse response,p(t),and transmitter symbol response,c(t),Shows BER of transmitted data given timing uncertainty(data jitter,clock jitter)and voltage uncertainty(VREF,Rx

34、 sensitivity,ISI),Find PDF(Probability Density Function)&CDF(Cumulative Distribution Function)of the channel,Plot BER eye-diagram as a function of sample time,sample voltage,and probability of error,Micron Engineering Clinic,Fall 08 Spring 09,Questions?,Micron Engineering Clinic,Fall 08 Spring 09,MO

35、DELING JITTER IN CHIP-to-CHIP COMMUNICATION,M.Lucas LoeroTechnical LeadElectrical EngineerLucas.loeroutah.edu,Micron Engineering Clinic,Fall 08 Spring 09,PRESENTATION OBJECTIVES,Defining JitterProblems caused by JitterModeling Jitter Receiver Jitter Transmitter Jitter Total Jitter,Micron Engineering

36、 Clinic,Fall 08 Spring 09,DEFINING JITTER,Time,Voltage,Ideal edge location,Edge location shifted,Ideal edge location,Jitter,Micron Engineering Clinic,Fall 08 Spring 09,PROBLEMS CAUSED BY JITTER,Power supply and environment noise causes Jitter.Jitter can lead to:Time uncertainty Suboptimal sampling t

37、imeReduce noise margin,Micron Engineering Clinic,Fall 08 Spring 09,PROBLEMS CAUSED BY JITTER,Micron Engineering Clinic,Fall 08 Spring 09,Model the effects of Jitter in high-speed serial linksSerial links are used for high-speed chip-to-chip communications,MODELING JITTER,Micron Engineering Clinic,Fa

38、ll 08 Spring 09,MODELING JITTER,Serial Links,Transmitter generates a train of pulses,Transmitter clock,Sampler,Decision circuit,Micron Engineering Clinic,Fall 08 Spring 09,MODELING JITTER,Traditional approach to modeling jitterThere is two main problems with this approached First,simulation time Sec

39、ond,difficulty simulating serial links,Micron Engineering Clinic,Fall 08 Spring 09,Receiver Jitter,Independent and Identically Distributed,Transmitted bits,Step response,Channel impulse response,Jitter sequence,MODELING JITTER,Micron Engineering Clinic,Fall 08 Spring 09,Calculated eye diagram,Simula

40、ted eye diagram,MODELING JITTER,Micron Engineering Clinic,Fall 08 Spring 09,Worst-case receiver jitter,MODELING JITTER,Micron Engineering Clinic,Fall 08 Spring 09,Worst-case ISI,Worst-case receiver jitter,MODELING JITTER,Worst-case receiver eye,Time,Voltage,Voltage,Time,Micron Engineering Clinic,Fal

41、l 08 Spring 09,MODELING JITTER,Worst-case receiver eye,Micron Engineering Clinic,Fall 08 Spring 09,Transmitted bits,Step response,Channel impulse response,Jitter sequence,MODELING JITTER,Transmitter Jitter,Micron Engineering Clinic,Fall 08 Spring 09,MODELING JITTER,Worst-case transmitter Jitter,Micr

42、on Engineering Clinic,Fall 08 Spring 09,Worst-case ISI,Worst-case transmitter jitter,MODELING JITTER,Worst-case transmitter eye,Time,Time,Voltage,Voltage,Micron Engineering Clinic,Fall 08 Spring 09,MODELING JITTER,Worst-case transmitter eye,Micron Engineering Clinic,Fall 08 Spring 09,MODELING JITTER

43、,Total Jitter,Transmitter Jitter,Receiver Jitter,Micron Engineering Clinic,Fall 08 Spring 09,MODELING JITTER,Worst-case total Jitter,Micron Engineering Clinic,Fall 08 Spring 09,Worst-case ISI,Worst-case total jitter,MODELING JITTER,Worst-case total eye,Time,Time,Voltage,Voltage,Micron Engineering Cl

44、inic,Fall 08 Spring 09,MODELING JITTER,Worst-case total eye,Micron Engineering Clinic,Fall 08 Spring 09,CONCLUSION,Voltage,Time,Micron Engineering Clinic,Fall 08 Spring 09,Questions?,Micron Engineering Clinic,Fall 08 Spring 09,Project Software Engineering,Development,and ResultsBen MeakinTeam LeadCo

45、mputer Engineermeakincs.utah.eduMicron Engineering ClinicSpring 09,Micron Engineering Clinic,Fall 08 Spring 09,Introduction,Open Eye:A Formal Verification Tool for High Speed Electrical Signaling,What is Open Eye?Provides Software Infrastructure Required to Deliver a Useful Verification Platform Bas

46、ed on Existing State-of-the-Art Methods,Presentation Outline Requirements and Objectives Software Architecture Graphical User Interface(GUI)Software Infrastructure Use Case Summary and Conclusions,Micron Engineering Clinic,Fall 08 Spring 09,Product Requirements,Cross Platform(Windows,Linux,etc)Graph

47、ical User Interface No Proprietary Software License(i.e.Matlab License)Correctly Implement Worst-Case and Statistical Link Analysis Pass Fail Mask and Data Eye Visualization Selectable Transmitter and Receiver Jitter Multiple Sources of Co Channel Interference Spice Data File Input,Micron Engineerin

48、g Clinic,Fall 08 Spring 09,Product Release Status,FeaturePhaseStatus,Worst-Case AnalysisReleaseStatistical AnalysisTesting25%Static AnalysisReleaseBasic PlottingReleaseAdvanced PlottingDevelopment50%Jitter ModelingDebug75%Co-Channel InterferenceTesting75%File InputReleaseFile OutputDevelopment75%Gra

49、phical User InterfaceTesting50%Multi-threadingTesting75%DocumentationDevelopment50%,Micron Engineering Clinic,Fall 08 Spring 09,Design Goals,Portability Extensibility Usability,View,Micron Engineering Clinic,Fall 08 Spring 09,Object Oriented Design,Model,Data IO,Signal Analysis,Parameters,Static Dat

50、a,StatisticalData,Worst-CaseData,Range,MathUtility,SignalModify,Open EyeApp.,Open EyeView,OtherGUIClasses,View,Status Q,Model,Control,Data Structures,Micron Engineering Clinic,Fall 08 Spring 09,Graphical User Interface Features,Micron Engineering Clinic,Fall 08 Spring 09,Graphical User Interface Fea