Upload
others
View
3
Download
0
Embed Size (px)
Citation preview
Mohamed Hafed & Steven ChiangIntrospect Technology & Trust-Tek Corporation
PracticalExperiencesinMIPID-PHYSMandC-PHYSM ReceiverTesting
©2017MIPIAlliance,Inc.
InTheory…
2
DUTTestInstrument
©2017MIPIAlliance,Inc.
InRealLife…
3
IPBring-Up
• TestIPinisolation
• Theoreticalcase(perhaps!)
ComponentBring-Up
• Focusonentirechipfunctionalityincludinginterface
• Othereffectsstarttoappear
ApplicationModuleBring-Up
• Whereisthereceiver?
• Whereisthechannel?
• Whatstimulustouse?
TestRequirementsThroughProductLifecycleStages
©2017MIPIAlliance,Inc.
Agenda• Overviewofreceivertest• Illustrationofpracticalmoduleimplementationsand
evaluationplatforms• Recommendationsandbestpractices
4
©2017MIPIAlliance,Inc.
PhysicsofSignalTransmission
5
Transmitter
LargeSignalSmallNoise
Channel(cable,connector,flexPCB,package)
Receiver
SmallSignalLargeNoise
©2017MIPIAlliance,Inc.
ObjectiveofReceiverTest
6
Generateastressedsignalasifitwentthroughachannel
- ModelISI- ModelDCD- ModelJitter
Receiver
SmallSignalLargeNoise
©2017MIPIAlliance,Inc.
MIPID-PHYSM ReceiverSpecification
7
MIPID-PHYSMGenerator
DataRxClockRx
ReferenceChannel
ReferenceChannel
©2017MIPIAlliance,Inc.
MIPIC-PHYSM ReceiverSpecification
8
MIPIC-PHYSMGenerator DataRxReferenceChannel
©2017MIPIAlliance,Inc.
TheLinearChannelModel
9
Freq
|S21|
ΦS21
Freq
Freq
GrpDelayS21
©2017MIPIAlliance,Inc.
TheLinearChannelModel
10
LinearChannel
TimingEdgesLargelyUnaffectedinaLinearChannel
©2017MIPIAlliance,Inc.
TheLinearChannelModel
11
LinearChannel
TimingEdgesLargelyUnaffectedinaLinearChannel
Resultsinalmostnon-realisticjitterinjectionrequirements
©2017MIPIAlliance,Inc.
PracticalEvaluationBoard…Nonlinear!
12
IC
TestInstrument
FlexFlex
Discontinuity(Connector)
Discontinuity(Connector)BendorViaDiscontinuity
(TestPoint)
Discontinuity(Connector)
Discontinuity(Connector)
©2017MIPIAlliance,Inc.
LinearChannelVersusNon-LinearChannel
13
TxEyeDiagram
LinearChannelEyeDiagram(~0.3UIClosure)
©2017MIPIAlliance,Inc.
LinearChannelVersusNon-LinearChannel
14
TxEyeDiagram Non-LinearChannelEyeDiagram(~0.4UIClosure)Channelis25%Shorter
©2017MIPIAlliance,Inc.
PracticalExperiences:Skew
15
IC
TestInstrument
FlexFlex
BendorVia
©2017MIPIAlliance,Inc.
PracticalExperiences:Skew
16
PosNeg
PosNeg
CommonMode
Skewintroducescommon-modenoise(notgoodforreceiver!)Difficult todetectondifferentialscopeeyediagram
©2017MIPIAlliance,Inc.
PracticalExperiences:Reflections
17
IC
TestInstrument
FlexFlex
Discontinuity(Connector)
Discontinuity(Connector)
©2017MIPIAlliance,Inc.
PracticalExperiences:Reflections
18
Worst-caseexampleofachannelnon-linearity
Signalrisetimeissharp,butreflectionscancausebitflips
©2017MIPIAlliance,Inc.
PracticalExperiences:Reflections
19
StubCausingCompleteEyeClosure SlowingDataRateRevealsStubWaveform
©2017MIPIAlliance,Inc.
PracticalExperiences:Grounding
20
IC
TestInstrument
FlexFlex
Connector
Connector
©2017MIPIAlliance,Inc.
PracticalExperiences:Grounding
21
HSeyediagramaffectedbyCMandDiffeffectsLPwaveformsaffectedbycrossinglevelsandreflections
©2017MIPIAlliance,Inc.
PracticalExperiences:Inductance
22
IC
TestInstrument
FlexFlex
Discontinuity(TestPoint)
©2017MIPIAlliance,Inc.
PracticalExperiences:Inductance
23
Oftenduetotestpoints
Makescorrelationwithspecificationsdifficult
©2017MIPIAlliance,Inc.
Recommendations
24
Adoptasystem-levelapproachtotest ifyourevaluationboardlookslikeasystem
Identifystressparameterssuitableforcharacterizingyourdeviceinitsenvironment
Characterizereceiverperformanceacrosssystemconstraintsaswellasthroughideal“linear”channel