CAN物理层讨论

Manynetworkprotocolsaredescribedusingtheseven

layerOpenSystemInterconnection(OSI)model,as

showninFigure1.TheControllerAreaNetwork(CAN)

protocoldefinestheDataLinkLayerandpartofthe

PhysicalLayerintheOSImodel.Theremainingphysi-

callayer(andallofthehigherlayers)arenotdefinedby

theCANspecification.Theseotherlayerscaneitherbe

definedbythesystemdesigner,ortheycanbeimple-

mentedusingexistingnon-proprietaryHigherLayer

Protocols(HLPs)andphysicallayers.

TheDataLinkLayerisdefinedbytheCANspecifica-

tion.TheLogicalLinkControl(LLC)managestheover-

loadcontrolandnotification,messagefilteringand

recoverymanagementfunctions.TheMediumAccess

Control(MAC)performsthedataencapsulation/decap-

sulation,errordetectionandcontrol,bitstuffing/de-

stuffingandtheserializationanddeserialization

functions.MAN228ACANPhysicalLayerDiscussionThePhysicalMediumAttachment(PMA)andMediumAuthor:PatRichardsDependentInterface(MDI)arethetwopartsoftheMicrochipTechnologyInc.physicallayerwhicharenotdefinedbyCAN.ThePhysicalSignaling(PS)portionofthephysicallayerisINTRODUCTIONdefinedbytheCANspecification.Th