CAN-FD相关协议介绍

©2013.VectorInformatikGmbH.Allrightsreserved.AnydistributionorcopyingissubjecttopriorwrittenapprovalbyVector.V1.02013-01-10AnIntroductionCANFDFlexibleDataRateCAN©2013.VectorInformatikGmbH.Allrightsreserved.AnydistributionorcopyingissubjecttopriorwrittenapprovalbyVector.Slide:2AgendaWhyCANFD?WhatisCANFD?CANFDUseCasesAutomotiveApplicationDomainsCANFDFrameCANFDControllerCANFDPerformanceCANFDDevicesCANFDStandardizationToolsandHardwareforCANFDTools,HardwareandSWComponentsforCANFDReferences©2013.VectorInformatikGmbH.Allrightsreserved.AnydistributionorcopyingissubjecttopriorwrittenapprovalbyVector.Slide:3WhyCANFD?ManyCANbuseshavereached50%…95%busloadlevel1.Busspeedlimitedto1Mbit/s(typical≤500kbit/s)Limitedbyphysicalcharacteristicsofin-vehiclewiringduetotheIn-Frameresponsemechanism:ACKgenerationdelayinCANcontrollerPropagationdelaythroughthetransceiverPropagationdelayoverwire2.CANmessagescontain≥50%overheadOtherprotocolshavelessoverheadEthernetUDP–~64kbytes/datagram,64bytesoverhead(IPV4)FlexRay–254bytes/frame,8bytesofoverheadCAN_HCAN_LCAN-ECURTCAN-ECU©2013.VectorInformatikGmbH.Allrightsreserved.AnydistributionorcopyingissubjecttopriorwrittenapprovalbyVector.Slide:4AgendaWhyCANFD?WhatisCANFD?CANFDUseCasesAutomotiveApplicationDomainsCANFDFrameCANFDControllerCANFDPerformanceCANFDDevicesCANFDStandardizationToolsandHardwareforCANFDTools,HardwareandSWComponentsforCANFDReferences©2013.VectorInformatikGmbH.Allrightsreserved.AnydistributionorcopyingissubjecttopriorwrittenapprovalbyVector.Slide:6WhatisCANFD?CANFDisanimprovedCANprotocol(basedonCAN2.0)Twofeaturesadded:ChangeslimitedtoCANcontrollerhardware1.SupportdualbitrateswithinamessageArbitration-Phase:samebitrateasstandardCANData-Phase:bitratesupto5Mbit/ssmallsoftwarechangeneeded(duetochangeoftiming)2.Supportlargerpayload(datalength)Upto64bytes/messagelargersoftwarechangeneeded©2013.VectorInformatikGmbH.Allrightsreserved.AnydistributionorcopyingissubjecttopriorwrittenapprovalbyVector.Slide:7WhatisCANFD?SystemcostsimilartostandardCANController,crystal,transceiver,nodeinterconnectioncostExistingCANtransceiversusableupto2-5Mbit/sdependingontheapplicationWellknowntechnology:Event-TriggeredsystemSmoothmigrationatreasonablecostpossibleClassicCANandCANFDECUscanbemixedundercertainconditions©2013.VectorInformatikGmbH.Allrightsreserved.AnydistributionorcopyingissubjecttopriorwrittenapprovalbyVector.Slide:8WhatisCANFD?Scenario1SomenodesarenotCANFDcapable:CommunicateonlywithclassicCANmessagesorswitchoffthenot-capablenodes(e.g.duringflashing)Scenario2AllnodesareCANFDcapable:ClassicandFDmessagescanbemixedCombiningCANandCANFD©2013.VectorInformatikGmbH.Allrightsreserved.AnydistributionorcopyingissubjecttopriorwrittenapprovalbyVector.Slide:9CANFDUseCasesUsecasesforCANFDFastersoftwaredownloadAvoidsplitofdataintoseveralframesDecreasebusloadofanexistingbusIncreaseNo.ofECUsonthebusAvoidsplitofnetworksCommunicationwithECUswithhighdatavolumeAcceleratecommunicationonlongbuslines(truck/bus)©2013.VectorInformatikGmbH.Allrightsreserved.AnydistributionorcopyingissubjecttopriorwrittenapprovalbyVector.Slide:10AutomotiveApplicationDomainsImplementationcostDatarateSensors&actuatorsConveniencePowertrain&chassisAssistance&X-by-wireLINCANLSCANHSFlexrayBandwidthandCostDriverAssistanceInfotainmentMOST150Ethernet,BroadR-Reach,IEEERTPGECANFD©2013.VectorInformatikGmbH.Allrightsreserved.AnydistributionorcopyingissubjecttopriorwrittenapprovalbyVector.Slide:12AgendaWhyCANFD?WhatisCANFD?CANFDUseCasesAutomotiveApplicationDomainsCANFDFrameCANFDControllerCANFDPerformanceCANFDDevicesCANFDStandardizationToolsandHardwareforCANFDTools,HardwareandSWComponentsforCANFDReferences©2013.VectorInformatikGmbH.Allrightsreserved.AnydistributionorcopyingissubjecttopriorwrittenapprovalbyVector.Slide:13CANFDFrameCANFDFrameArbitrationPhase(standardbitrate)ArbitrationPhase(standardbitrate)DataPhase(optionalhighbitrate)Consistoftwophases–ArbitrationphaseandDataphaseSOF1r1IDEEDLr0ESIACKACKDelimiterCRCDelimiter1BRS11111111Identifier11DLC4Data0..512CRC17/21EOF7IFS31111EOF711CANFDExtendedFrame111SOFr1EDLr0ESIACKACKDelimiterCRCDelimiterBRSIdentifier11DLC4Data0..512CRC17/21IFS3IDEExtendedIdentifier18SRR1111ArbitrationPhaseDataPhaseArbitrationPhase©2013.VectorInformatikGmbH.Allrightsreserved.AnydistributionorcopyingissubjecttopriorwrittenapprovalbyVector.Slide:14CANFDFrameCANFDFrameArbitrationFieldStartOfFrameControlFieldDataFieldCRCFieldACKFieldEndOfFrame…andsevendifferentbitfields–SOF,Arbitration,Control,Data,CRC,ACK,EOFSOF1r1IDEEDLr0ESIACKACKDelimiterCRCDelimiter1BRS11111111Identifier11DLC4Data0..512CRC17/21EOF7IFS3©2013.VectorInformatikGmbH.Allrightsreserved.AnydistributionorcopyingissubjecttopriorwrittenapprovalbyVector.Slide:16CANFDFrameArbitrationFieldLittledifferencebetweenCANandCANFDarbitrationfieldsBothsharethesameaddressingforStandardandExtendedformatsCANFDremovestheRTRbitandmaintainsanalwaysdominantr1bitCANframeCANFDframeData0..5121SOF1r1IDEEDLr0ESIBRS11111Identifier11DLC4SOF1RTRr111r01Identifi