Issue with 50G PAM4 C2M Specificationgrouper.ieee.org/groups/802/3/bs/public/adhoc/elect/23...qBased...
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Issue with 50G PAM4 C2M Specification Ali Ghiasi Ghiasi Quantum LLC IEEE 802.3bs Electrical Adhoc Meeting Jan 23rd, 2017
Transcript of Issue with 50G PAM4 C2M Specificationgrouper.ieee.org/groups/802/3/bs/public/adhoc/elect/23...qBased...
Issuewith50GPAM4C2MSpecification
AliGhiasiGhiasi QuantumLLC
IEEE802.3bsElectricalAdhoc Meeting
Jan23rd,2017
q RichMellitz – Samtecq Yasuo Hidaka– Fujitsu
A.Ghiasi IEEE802.3bs TaskForce 2
Contributor/Supporter
Backgroundq TheIEEE802.3bsC2Msimulationshavenotdemonstratedoperationover10.2dBchannelwithmax
FEXT/NEXTq Thebasesimulationshaveconsistedof
– 6TEhypotheticalchannelswithcrosstalk~1/6ofMDIdefinitionofclause92andreferencedbyCL120.E– 2Ciscochannelswithnocrosstalk
q Historyofcommentsonthisissue– ThisissuewasfirstraisedwithComment128againstP802.3bsdraft1.4thatmatedboardofCL92
crosstalkisexcessiveinsupportof50GCucabling– Comments83and86aresubmittedagainstD2.0relatedtoexcessivecrosstalknotconsideredinthebaseline
C2M– Comments135againstD2.1relatedtoexcessivecrosstalknotconsideredinthebaselineC2M
q Severaltimeshaverequestedrepresentativeclause92MDIdataformoreaccuratesimulationbutnonewdatahasbeenprovided
q Clause92MDIdatawithoutcrosstalkshowjustaboutpassesverticaleyeopening– Thereisverystrongindicationthatclause120.efailsbadlyfarendeyeopening– HavingMDIdatawhichincludecrosstalkdatawillimprovethesimulationresultsandaccuracy.
A.Ghiasi 3IEEE802.3bsTaskForce
50GMatedBoardReferencesLegacyCL92MCB/HCBSpecifications
q CurrentlyCL120E.4.1MCB/HCBspecificationsreferences– CL92.11.1forHCBspecifications– CL92.11.2fortheMCBspecifications– CL92.11.3.6definesmatedtextfixtureICN
• MDFEXTof4.8mVisexcessivefor50GPAM4link!
A.Ghiasi 4IEEE802.3bsTaskForce
BasesfortheMatedMCB/HCBMDFEXT/MDNEXTinCL92
q QSFP+connectorprovidedbasesfortheCL92MDFEXTandMDNEXT– QSFP28doesprovideslightimprovementbutin802.3cddecidedtostaywiththeselegacylimits– http://www.ieee802.org/3/bj/public/sep12/ghiasi_3bj_01a_0912.pdf
A.Ghiasi 5
MCB-HCB Crosstalk10.3125 GBdICN (mV)
25.78 GBdICN (mV)
28.0 GBd ICN(mV)
Rise Time 20-80% (ps) 24.000 9.600 8.840
MDNEXT 0.323 1.390 1.612
MDFEXT 3.593 4.562 4.673
ICN 3.607 4.769 4.943
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IEEE802.3bsTaskForce
HypotheticalChannelUsedforC2MAnalysisHasSignificantlyLowerNEXT/FEXT
q CDAUI-8/CCAUI-4basechannels– http://www.ieee802.org/3/bs/public/adhoc/elect/24Aug_15/dallaire_01_082415_elect.pdf
A.Ghiasi 6
Testcase3and5HavingalosssimilartomatedboardareUsedforCrosstalkAnalysis
IEEE802.3bsTaskForce
CrosstalkforC2MTestCase3and5q MatedboardhadnoNEXTandwithexcellentFEXT
– http://www.ieee802.org/3/bs/public/channel/TEC/shanbhag_3bs_01_1014.pdf– C2Marebasedonchannelswith5-7xlowercrosstalkthanmatedboardreferencedcurrently!
A.Ghiasi 7
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IL, dB MDNEXT MDFEXT
TestCase3SMTConnectorMDFEXT=0.698mV
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TestCase5PressFitConnectorMDFEXT=1.044mV
IEEE802.3bsTaskForce
BaselineC2MSimulationSummary
q BaselineC2MsimulationCOManalysisforthehypotheticalchannelswith5-7xlowercrosstalkdoesn’tevenhavemarginevenwithCTLE+TXFIR+LFEQat1E-5BER!– Increasingcrosstalkby5-7xonchannelsbelowwithcurrentlinkconfigurationandequalizerwill
bedetrimental!– Summaryresultsfrom
http://www.ieee802.org/3/bs/public/adhoc/elect/24Aug_15/dallaire_01_082415_elect.pdf
A.Ghiasi IEEE802.3bsTaskForce 8
IEEECOMRev165Parameters
A.Ghiasi 9
Table93A-1parameters I/Ocontrol Table93A–3parametersParameter Setting Units Information DIAGNOSTICS 1 logical Parameter Setting Units
f_b 26.5625 GBd DISPLAY_WINDOW 1 logical package_tl_gamma0_a1_a2 [01.734e-31.455e-4]f_min 0.05 GHz Displayfrequencydomain 1 logical package_tl_tau 6.141E-03 ns/mmDelta_f 0.01 GHz CSV_REPORT 1 logical package_Z_c 85 OhmC_d [1.8e-40] nF [TXRX] RESULT_DIR .\results\C2C_{date}\
z_pselect [2] [testcasestorun] SAVE_FIGURES 0 logical Table92–12parametersz_p(TX) [612] mm [testcases] PortOrder [1324] Parameter Setting
z_p(NEXT) [630] mm [testcases] RUNTAG c2m_MTF board_tl_gamma0_a1_a2 [04.114e-42.547e-4]z_p(FEXT) [120] mm [testcases] Receivertesting board_tl_tau 6.191E-03 ns/mmz_p(RX) [00] mm [testcases] RX_CALIBRATION 0 logical board_Z_c 109.8 OhmC_p [0.9e-40] nF [TXRX] SigmaBBNstep 5.00E-03 V z_bp(TX) 150 mmR_0 50 Ohm IDEAL_TX_TERM 0 logical z_bp(NEXT) 0 mmR_d [5550] Ohm [TXRX] T_r 1.30E-02 ns z_bp(FEXT) 0 mmf_r 0.75 *fb FORCE_TR 1 logical z_bp(RX) 0 mmc(0) 0.6 minc(-1) [-0.15:0.05:0] [min:step:max] Nonstandardcontroloptionsc(-2) [0:0.025:0.1] INC_PACKAGE 1 logicalc(1) [-0.25:0.05:0] [min:step:max] IDEAL_RX_TERM 0 logicalg_DC-[11.522.533.544.555.566.577.588.59]dB [min:step:max] INCLUDE_CTLE 1 logicalf_z[8.3598.1597.9957.6046.7136.4216.1555.7335.3535.0074.6914.3994.133.883.6473.433.228]GHz INCLUDE_TX_RX_FILTER 1 logicalf_p1[18.618.618.618.615.615.615.615.615.615.615.615.615.615.615.615.615.6]GHz COM_CONTRIBUTION 0 logicalf_p2[14.114.114.114.114.114.114.114.114.114.114.114.114.114.114.114.114.1]GHzA_v 0.45 VA_fe 4.14 VA_ne 0.63 VL 4M 32N_b 0 UI
b_max(1) 0.5b_max(2..N_b) 0.2
sigma_RJ 0.01 UIA_DD 0.02 UIeta_0 0.00E+00 V^2/GHzSNR_TX 31 dBR_LM 0.95DER_0 1.00E-05
Operationalcontrol 1COMPassthreshold 3 dB
IncludePCB 1 Value 0,1PHY_type C2MEH_min 32 Value EHlimitEH_max 1000 Value EHlimitf_HP_P[1.21.21.21.21.21.21.21.21.21.21.21.21.21.21.21.21.2]GHzf_HP_Z[1.21.151.11.0751.051.02511111111111]GHz
http://www.ieee802.org/3/cd/public/channel/mellitz_3cd_01_1116_COM.zip
1Adds150mmofPCB,0noextraPCB
IEEE802.3bs TaskForce
ResultswithMTFTestBoardq TP1aresponseoftheMTFtestboard+150mmtracehasoutputVEO=32.2mVwithout
anycrosstalkjustpassesthelimitinCL120.E!– MTFboardhttp://www.ieee802.org/3/bs/public/channel/mccom/diminico_3bs_01_0516.s4p
A.Ghiasi IEEE802.3bs TaskForce 10
UsingCOMversion165ResultsforMTFlikechannelwithIL_fit=10.25dBVEO=32.2mV,ICN=0mV,PeakISI=10.8mV,MDFEXTPeak=0mVCOM=5.13dB
4”TEStacked50GChannelMeetingMTFq BasedonTEhypotheticalconnectorwithIL_Fit of4.3dBbuthavingMDFEXTp-p=2.37mV
(MDFEXTRMSforBER1E-5=2.37/4.26=0.56mV)– ToaccountforworstcaseMDFEXT=4.8mVandMDNEXT=1.8mV(PSXT=5.13mVRMS)A_fe ininCOMwasadjusted
from0.45to4.12inordertogetMDFEXTp-pof21.84mVequivalenttoPSXTof5.13mVRMSpertable92-13– http://www.ieee802.org/3/bs/public/channel/TEC/shanbhag_3bs_01_1014.pdf
A.Ghiasi IEEE802.3bs TaskForce 11
UsingCOMversion165ResultsforMTFlikechannelwithIL_fit=4.3dBResultsforA_fe=0.45:VEO=58mV,ICN=1.237mV,PeakISI=21.5mV,MDFEXTPeak=2.37mVCOM=5.01dBResultswithA_fe=4.12:VEO=42.5mV,ICN=1.237mV,PeakISI=21.5mV,MDFEXTPeak=21.88mVCOM=3.36dB
10”TEStacked50GChannelq BasedonTEhypotheticalconnectorwithIL_Fit of8.8dBshyofclause120.Elossof10.2dB
– Sincethe4”and10”TEstackboardshavesimilarconstructionwithexceptionofonewithlongertrace,thecalibratedA_fe crosstalkofthe4”boardisusedforthe10”board
– http://www.ieee802.org/3/bs/public/channel/TEC/shanbhag_3bs_01_1014.pdf
A.Ghiasi IEEE802.3bs TaskForce 12
UsingCOMversion165ResultsforMTFlikechannelwithIL_fit=4.3dBResultsforA_Fe=0.45:VEO=37.5mV,ICN=0.759mV,PeakISI=11.55mV,MDFEXTPeak=1.39mVCOM=5.28dBResultswithA_Fe=4.14:VEO=28.2mV(failing),ICN=0.759mV,PeakISI=11.55mV,MDFEXTPeak=12.89mVCOM=3.65dB
10”TEStacked50GChannelq BasedonTEhypotheticalconnectorwithIL_Fit of8.8dBshyofclause120.Elossof10.2
dB,toincreasethelossto31mmofPCBtraceperclause120isadded– Sincethe4”and10”boardaresimilarwithexceptionofthelongertrace,calibratedA_fe
crosstalkiskeptat4.14forthe10”board+31mmPCBtrace
A.Ghiasi IEEE802.3bs TaskForce 13
UsingCOMversion165ResultswithA_fe=4.14:VEO=21.2mV(failing),ICN=0.759mV,PeakISI=11.38mV,MDFEXTPeak=12.84mV,COM=3.03dB
QSFPMTF+CrosstalkfromTE4”Stackedq QSFPMTF(diminico_3bs_01_0516.s4p)doesnothaveanycrosstalkdata
– TE4”stackedwithIL_Fit of⋍4.3isusedasthecrosstalksource– 150mmofPCBtraceisaddedperclause92toincreasethelossto10.2dB– ThecalibratedcrosstalksourceisA_fe=4.14
A.Ghiasi IEEE802.3bsTaskForce 14
UsingCOMversion165ResultswithA_fe=4.14:VEO=10.9mV(failing),ICN=1.237mV,PeakISI=10.7mV,MDFEXTPeak=20.87mVCOM=1.43dB
Summaryq P802.3bsclause120.EwhichreferenceCL92hasexcessiveamountofMDFEXT(4.8mV)andMDNEXT
(1.8mV)q 802.3bsC2Msimulationinsupportof50G/lanePAM4werebasedonaTEhypotheticalconnectorwith
~6xlowerFEXTandNEXTanddoesnotprovidedtechnicalfeasibilitywithcurrentMDIdefinitionq IEEEP802.3bsandcdneedtocollectivelyworktogethertoresolvethisissuesoonerthanlaterto
minimizetheimpact– Havingrepresentativeclause92MDIdatawithcrosstalkwillbeveryhelpful
q Potentialareaneedtobeconsideredinordertoclosethemajorholeinclause120.Especification– Clause92MDIcrosstalkwasbasedonthedataIpresentedin802.3bjover5yearsagoneedtobetighten
by~3xforrobustPAM4operation– TEhypotheticalconnectorisproofthatimprovedconnectorcanbedeveloped,couldTEorotherpossibly
developanimprovedconnectorcompatiblewithCL92MDI– CurrentfarendeyeopeningofEW1E-5=0.22andEH1E-5=32mVhasverylittleroomforfurthertightening– Tightentransmitterparameterssuchasjitterandrisetimecanprovidedsomereliefbutnotenoughto
closethelinkbudget– UseCOMasthetooltotradeoffloss,crosstalk,andISInowthatthereareseveralMDI’seachwith
somewhatdifferentcharacteristicsaretargetedfor802.3bs/cdimplementation– Defineamorepowerfulequalizerforthechip-to-module.
A.Ghiasi 15IEEE802.3bsTaskForce
