Tiêu chuẩn iso 11898 1 2015

They ar the folowing: — sup ort of the Clas ical CANframe format only, not t ole ating the Flexible Data Rat e frame format ; — sup ort of the Clas ical CANframe format an t ole ating th

Road vehicles — Control er area

Part 1:

Vé icule s ro tiers — Gestion aire de résea de commu ication

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© ISO 201 , P blshed in Sw itz rlan

A ll rig hts r eserved Unles otherw ise spe ified, nopar of this p blc tion ma y be r epr od c d or utilz d otherw ise in an form

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written permis ion Permis ion c n be req esed from either ISO at the ad r es below or ISO’s member bod y in the c u try of

F reword vi

Introduction vii

1 Sc ope 1

2 Co for manc e 1

3 Nor mati ve r eferenc es 2

4 Terms and definitio s 2

5 Symbols and abbreviated terms 5

6 Basic c onc epts of CA N 7

6.1 CA N prope ties

7 6.2 Frames 8

6.3 Bus ac es method 8

6.4 Information r outing 8

6.5 Networ k flex ibi ty 8

6.6 Data consis ency 8

6.7 Remote data r eq es 8

6.8 Err or dete tion 9

6.9 Err or sig nal ng an r eco e y time 9

6.1 ACK 9

6.1 Automatic r etransmis ion 9

6.1 Fault confinement .9

6.1 Err or-active 9

6.14 Err or-p s ive 9

6.1 Bus-of 1

7 Layer ed architecture of CA N 10

7.1 Referenc to OSI model 1

7.2 Pr otocol spe ification 1

7.3 Format desc iption of se vic s 1

7.3.1 Format desc iption of se vic primitives 1

7.3.2 T ypes of se vic primitives 1

7.4 L C inte fac 1

8 Des riptio of L C sub- ayer 12

8.1 General 1

8.2 S rvic s of L Csub-la ye 1

8.2.1 T ypes of con e tionles -mode transmis ion se vic s 1

8.2.2 S rvic primitive spe ification 1

8.3 Fu ctions of L Csub-la ye

1 8.3.1 General 1

8.3.2 Frame ac eptanc fite ing 1

8.3.3 Over lo d notification 1

8.3.4 Re o e y manag ement 1

8.4 Structur e of L Cframes 1

8.4.1 General 1

8.4.2 Spe ification of L C DF 1

8.4.3 Spe ification of L C RF 2

8.5 Limited L C fr ames 2

9 Inter fac e betwe n LL C and MAC 21 9.1 S rvic s 2

9.2 Time an time trig g ering 2

9.2.1 Desc iption 2

9.2.2 Time b se 2

9.2.3 Time r efer enc p int 2

9.2.4 Event g eneration 2

9.3 Disa lng automatic retransmis ion 2

9.3.1 Retr ansmis ion of frames .2

9.4 Mes ag e time s amping 2

10 Des r iptio of MAC sub- ayer 22 1 1 General 2

1 2 S rvic s of MAC sub-la ye 2

1 2.1 S rvic desc iption 2

1 2.2 S rvic primitives spe ification 2

1 3 Fu ctional model of MACsub-la ye ar chite tur e 2

1 3.1 C p bi ity 2

1 3.2 Frame tr ansmis ion 2

1 3.3 Frame r ec ption 2

1 4 Structur e of MAC frames .2

1 4.1 Descr iption 2

1 4.2 Spe ification of MAC DF 2

1 4.3 Spe ification of MAC RF 34

1 4.4 Spe ification of EF 34

1 4.5 Spe ification of OF 3

1 4.6 Spe ification of inte -frame sp c 3

1 5 Frame coding 3

1 6 Frame ack owledg ement 3

1 7 Frame v ldation 3

1 8 Orde of bit transmis ion 3

1 9 Medium ac es method 3

1 9.1 General 3

1 9.2 Multi-mas e 3

1 9.3 Bus ac es 40

1 9.4 Bus integ r ation s ate 40

1 9.5 Pr otocol exc ption event 40

1 9.6 Transmis ion of MAC frames 40

1 9.7 C ntent-b sed ar bitration 40

1 9.8 Frame priority 41

1 9.9 C l sion r esolution 41

1 9.1 Disa lng of fr ame format 41

1 1 MAC data consis ency 41

1 1 Error dete tion 41

1 1 Error sig nal ng 42

1 1 Over lo d sig nal ng 43

1 14 Bus monitoring 4

1 1 Res ricted o eration 4

11 PL specificatio 44

1 1 General and functional model ng

4 1 2 S rvic s of PL 4

1 2.1 Descr iption 4

1 2.2 PCS_ Data.Req es 45

1 2.3 PCS_ Data.In icate 45

1 2.4 PCS_ Status.Tr ansmite 45

1 2.5 PCS_ Status.Re eive 45

1 3 PCS spe ification .45

1 3.1 Bit encoding /de oding 45

1 3.2 Synchr onization 5

1 3.3 Transmite dela y compensation 5

1 4 AUI spe ification 54

1 4.1 General 54

1 4.2 PCSto PMA mes ag es 5

1 4.3 PMA to PCS mes ag e 5

12 Des riptio of super visor F E 55

1 1 Fault confinement .5

1 1.1 Obje tives 5

1 1.2 Strateg ies 5

1 1.3 Fault confinement inte fac spe ification 5

1 1.4 Rulesof fault confinement 5

1 1.5 Networ k start-up 6

1 2 Bus faiur e manag ement 6

A nne x A (informative)Additio al Informatio 61

Biblog raphy 65

ISO (he Int ernational Org nization for Stan ardization) is a worldwidefede ation of national s an ards

b dies (ISO membe b dies) The work of pr p ring Int ernational Stan ards is normaly car ied out

through ISO t ech ical committ ees Each membe b dy int er st ed in a subje t for w hich a t ech ical

committ ee has be n es a lshed has the right t o be r pr sent ed on that committ ee Int ernational

org nizations, g ove nmental an non-g ove nmental, in laison with ISO, also take part in the work

ISO cola orat es closely with the Int ernational Ele trot ech ical C mmis ion (IEC) on al matt ers of

ele trot ech ical s an ardization

The proc d r s used t o develo this document an those int en ed for it furthe maint enanc ar

desc ibed in the ISO/IEC Dir ctives, Part 1 In p rticular the dife ent a pro al c it eria ne ded for the

dife ent ty es of ISO document should be not ed This document was draft ed in ac ordanc with the

edit orial rules of the ISO/IEC Dir ctives, Part 2 ( e www.iso.org dir ctives)

A tt ention is drawn t o the p s ibi ity that some of the element of this document ma be the subje t of

p t ent right ISO shal not be held r sponsible for identifying any or al such p t ent right Detais of

any p t ent right identified d ring the develo ment of the document wi be in the Introd ction an / r

on the ISO ls of p t ent de larations r c ived ( e www.iso.org p t ent )

Any trade name used in this document is information given for the convenienc of use s an does not

cons itut e an en orsement

F or an ex lanation on the meaning of ISO spe ific t erms an ex r s ions r lat ed t o conformity

as es ment, as wel as information a out ISO’ s adhe enc t o the WTO principles in the Te h ical

Bar ie s t o Trade (TBT), se thefolowing URL:F or word — Sup lementary information

The committ ee r sponsible for this document is ISO/TC 2 , R oad vehicles , Subcommitt ee SC 3 , Data

c ommu ic atio

This se on edition canc ls an r plac sthe firs edition (ISO 1 8 8-1:2 0 ), w hich has be n t ech icaly

r vised It also incorp rat es the C r ig en um ISO 1 8 8-1:2 0 /Cor 1:2 06

ISO 1 8 8 consis s of the folowing p rt , u de the g ene al title R oad vehicles — Co trole ar a

net work (CAN):

— Part 1: Data lnk la e a d p ys ic al s ig al n

— Part 2 : Hig -s pe d medium ac c es s u it

1)

— Part 3 : L w-s pe d,f ult-tole a t, medium-dependent inte fc e

— Part 4 : Time-trig e ed c ommu ic ation

— Part 5: Hig -s pe d medium ac c es s u it w ith low-p we mode

ISO 1 8 8 was f irs publshed as one document in 1 9 It co e ed the CAN data lnk layer, as wel as

the high-spe d phy sical la e

In the r viewed an r s ructur d ISO 1 89 se ies:

— Part 1 def ines the data lnk la e inclu ing the lo ical l n control (L C)sub-la e an the medium

ac es control (MAC) sub-la e , aswel as the phy sical signal ng (PHS) sub-la e ;

— Part 2 def ines the high-spe d phy sical medium at achment PMA);

— Part 3 def ines the low-spe d fault-t ole ant phy sical medium at achment PMA);

— Part 4 def ines the time-trigg er d commu ication;

— Part 5 def ines the p we modes of the high-spe d phy sical medium at achment (PMA);

— Part 6 def ines the sele tive wake-up fu ctionalty of the high-spe d phy sical medium at achment

(PMA)

NOTE ISO 1 8 8-2 is u dated in paralel t o the u date of this part of ISO 1 8 8 t o combine the fu ctions

des rib d in ISO 1 8 8-2, ISO 1 8 8-5 an ISO 1 8 8-6 (T e future edition of ISO 1 8 8-2 wil cancel an

replace the cur ent ISO 1 8 8-2:2 0 , ISO 1 8 8-5:2 07 an ISO 1 8 8-6:2 1 )

Figur 1 show s the r lations between the OSIr fe enc la e s and the p rt of the ISO 1 89 se ies

NOTE ISO 1 8 8-2 refer t o the future edition that wil cancel an replace the cur ent ISO 1 8 8-2:2 0 ,

ISO 1 8 8-5:2 07 an ISO 1 8 8-6:2 1

Figure 1 — CAN data l nk and p y sical su - ayer relation to the OSI model

Road vehicles — Control er area networ k (CA N) —

Part 1:

This p rt of ISO 1 8 8 spe ifies the charact eris ics of set ing up an int er hang e of digital information

betwe n mod les implementing the CAN data l n la e C ntrol e ar a network is a se ial

commu ication prot ocol, w hich sup ort dis ribut ed r al-time control an multiplexing for use within

ro d vehicles an othe control a plcations

This part of ISO 1 8 8 spe if iesthe Clas ical CAN frame format an the new ly introd c d CAN Flexible

Data Rat e Frame format The Clas ical CAN frame format alow s bit rat es up t o 1 Mbit/s and p y lo ds

up t o 8 b t e pe frame The Flexible Data Rat e frame format alow s bit rat es highe than 1 Mbit/s an

p y lo ds long er than 8 b t e pe frame

This p rt of ISO 1 8 8 desc ibes the g ene al ar hit ectur of CAN in t erms of hie ar hical la e s

ac ording t o the ISO r fe enc model for o en sy st ems int er onne tion (OSI) ac ording t o ISO/IEC 749

-1 The CAN data lnk layer is spe if ied ac ording t o ISO/IEC 8 0 - 2 an ISO/IEC 8 0 -3

This part of ISO 1 89 contains detaied spe ifications of the folowing ( e Figur 2):

— lo ical lnk control sub-la e ;

— medium ac es control sub-la e ;

— phy sical coding sub-la e

The e ar thr e implementation o tions They ar the folowing:

— sup ort of the Clas ical CANframe format only, not t ole ating the Flexible Data Rat e frame format ;

— sup ort of the Clas ical CANframe format an t ole ating the Flexible Data Rat e frame format ;

— sup ort of the Clas ical CANframe format an the Flexible Data Rat e frame format

The las o tion isr commen ed t o be implement ed for new designs

NOTE Implementations of the f ir t option can commu icat e with implementations of the third option only

as long as the Fle ible Data Rat e frame format is not used; otherwise, Er or Frames are g nerated T ere are

op ortu ities t o ru implementations of the f ir t option also in CA networks using the Fle ible Data Rate frame

format, but these are not in the s ope of this part of ISO 1 8 8

The data l n la e conformanc t es plan is not in the sco e of this p rt of ISO 1 8 8 F or an

implementation t o be compl ant with this p rt of ISO 1 8 8, the lo ical l n control sub-la e an the

medium ac es control sub-la e shal comply with al man at ory spe if ications an v lues given in

this p rt of ISO 1 8 8 If o tional spe if ications an v lues ar implement ed, they shal comply, t oo

3 Normati ve referenc es

The folowing document , in w hole or in p rt, ar normatively r fe enc d in this document an ar

in ispensa le for it a pl cation F or dat ed r fe enc s, only the edition cit ed a pl es F or u dat ed

r fe enc s, the lat es edition of the r fe enc d document ( inclu ing any amen ment )a pl es

ISO/IEC 749 -1, Inormatio te h olo y — Open S s tems Inte c on ec tio — B as ic R efe enc e Model: The

B as ic Model — Part 1

ISO/IEC IEEE 8 0 -3:2 14, Sta dard fr Ethe net — Part 3

4 Terms and definitions

F or the purpose of this part of ISO 1 89 , the folowing t erms an def initions a ply

Not e 1 t o entry: Whenever the transmit ing lo ic encou ter a certain n mb r (stuf width) of consecutive bits

of eq al value in the data, it aut omatical y stufs a bit of complementary value—a stuf bit—int o the outg ing bit

stre m R eceiver de-stuf the Data Frames an the R emot e Frames, i.e the inver e proced re is car ied out

4.3

bus

t op lo y of a communication network, w he e al nodes ar r ached b p s ive lnks w hich alow

transmis ion in b th dir ctions

4.4

bus comparator

ele tronic cir uit conve ting phy sical signals used for trans e ac os the commu ication medium back

int o lo ical information or data signals

4.5

bus driver

ele tronic cir uit conve ting information or data signals int o phy sical signals so that these signals can

be trans e r d ac os the commu ication medium

4.6

bus state

one of two complementary lo ical s at es: dominant or r c s ive

Not e 1 to entry: The dominant state represents the lo ical 0, an the reces ive state represents the lo ical 1

During simultane us transmis ion of dominant an reces ive bits, the resulting bus stat e is dominant.When no

transmis ion is in pro res , the bus is idle.During idle time, it is in reces ive state

4.7

Clas ical Base Frame F ormat

format for Data Frames or R emot e Frames using an 1 -bit identifie , w hich ar transmitt ed with one

single bit rat e an up t o an inclu ing 8 data b t es

4.8

Clas ical Extended Frame F ormat

format for Data Frames or R emot e Frames using a 2 -bit identif ie , w hich ar transmitt ed with one

single bit rat e an up t o an inclu ing 8 data b t es

4 9

Clas ical Frame

Data Frame or R emot e Frame using the Clas ical Base Frame F ormat or the Clas ical Ext en ed Frame

data bit rate

n mbe of bit pe timed ring data phase, in epen ent of bit encoding de oding

4.12

data bit time

d ration of one bit in data phase

FD Base Frame F ormat

format for Data Frames using an 1 -bit identif ie , w hich ar transmitt ed with a flexible bit rat e an up

t o an inclu ing 64 data b t es

4.1 9

FD Extended Frame F ormat

format or Data Frames using a 2 -bit identifie , w hich ar transmitt ed with a flexiblebit rat e an upt o

an inclu ing 64 data b t es

frame

Prot ocol Data Unit of the data lnk la e spe ifying the ar ang ement an meaning of bit or bit f ields in

the seq enc of trans e ac os the transmis ion medium

4.24

handle

hardwar o je t la el of one or multiple L C frames (LPDU)

4.25

higher-ayer protocol

prot ocol a o e the Data Lin L ye prot ocol ac ording t o the Open Syst em Int er onne tion model

[ SOURCE:ISO/IEC 749 -1]

4.26

identifier

does not in icat e the des ination of the frame but r fle t the priority of a p rticular frame an denot es

the meaning of the data

s atus of a node waiting on an idle con ition aft er it has s art ed the prot ocol o e ation d ring bus-of

r co e y or aft er a prot ocol ex ception event

4.30

minimum time q antum

smales time q antum that can be con gur d for the spe if ic implementation

4.31

multicast

ad r s ing w he e a single frame is ad r s ed t o a group of nodes simultaneously

Not e 1 t o entry: Bro dcast is a special case of multicast, where y a single frame is ad res ed t o al nodes

as embly, l n ed t o a commu ication network, ca a le of commu icating ac os the network ac ording

t o a commu ication prot ocol spe ification

Not e 1t o entry: A CA node is a node commu icating ac os a CAN network

4.34

node clock

time b se t o co rdinat e the bit-time-r lat ed s at e machinesin CANimplementations

4.35

nominal bit rate

n mbe of bit pe timed ring arbitration phase, in epen ent of the bit encoding de oding

nominal bit time

d ration of one bit in arbitration phase

4.37

Non-Return-to-Zero

method of r pr senting binary signals, i.e within one an the same bit time, the signal level does not

chang e, w he e a s r am of bit ha ing the same lo ical v luepro ides no edg es

4.38

Over load Frame

frame in icating an o e lo d con ition

4.39

priority

at ribut e t o a frame control ng it ranking d ring the arbitration

Note 1t o entry: A high priority inc e ses the pro a ility that a frame wins the arbitration proces

4.40

protocol

formal set of conventions or rules for the ex chang e of information betwe n nodes, inclu ing the

spe if ication of frame adminis ration, frame trans e an PL

4.4

protocol exceptio event

ex ception from theformal set of conventions or rules t o be a le t o t ole at e futur new frame format

time-trigg ered communicatio

o tion whe e a frame can be transmitt ed in a defined time slo w hich also pro ides a networ k-wide

synchronization of clocks, as wel as disa lng of the a utomatic r transmis ion of frames, so that dedicated

data an r mote frames a oid col sions with data an r mote frames transmitted b othe nodes

node originating a data frame or r mot e frame, an s ay s transmitt er unti the bus is idle a ain or u ti

the node loses arbitration

5 Symbols and abbreviated terms

AUI A ttachment Unit Int erfac

BRS Bit Rat e Swit ch

CBF Clas ical Base Frame F rmat

CEF Clas ical Ext en ed Frame F ormat

ESI Er or Stat e In icat or

F E Fault Conf inement Entity

FDF FD F rmat in icat or

FEF FD Ext en ed Frame F ormat

HLP Higher-La e Prot ocols

IDE IDentif ie Ext ension

IP Information Proc s ing Time

L C L gical Link C ntrol

LPDU L CProt ocol Data Unit

MAC Medium A cc s Control

MAU Medium A ttachment Unit

MDI Medium Depen ent Int erfac

MPDU MAC Prot ocol Data Unit

MSB Mos Signif icant Bit

MSDU MAC S rvic Data Unit

NRZ Non-R eturn-t o-Ze o

OSI Open Sy st ems Int er on e tion

PCI Prot ocol Control Information

PCS P y sical C ding Sub-la e

PDU Prot ocol Data Unit

PMA P y sical Medium A ttachment

r0 R ese ved bit in Clas ical Ext en ed Frame F ormat

r s R ese ved bit in FD Frames

RRS R emot e R eq es Subs itution

RTR R emot e Transmis ion R eq es

SJW Synchronization Jump W idth

SRR Subs itut e R emot e R eq es

6 Basic c onc epts ofCA N

6.1 CA N properties

CAN has the fol owing pro e ties:

— multi-mast er priority-based bus ac es ;

— non-des ructive cont ent-based arbitration;

— al frame trans e isdone as bro dcast ;

— multicas frame trans e b ac eptanc f ilt ering;

— r mot e data r q est ;

— configuration flexibi ty;

— network-wide data consist ency;

— e ror det ection an e ror signal ng;

— aut omatic r transmis ion of frames that ha e los arbitration, ha e not be n ack ow ledg ed, or ha e

be n des ro ed b e rors d ring transmis ion;

— dis inction betwe n t emp rary e rors an pe manent faiur s of nodes an aut onomous swit ching

-of of defe tive nodes

Information on the bus is sent in f ix ed format frames of dife ent but lmit ed length When the bus is

idle, any conne t ed node is alowed t o s art the transmis ion of a DF or RF The bus is idle w hen no

frames ar transmitt ed Ad itionaly, any con e t ed node ma s art the in ication of e ror an o e lo d

information b means of dedicat ed frames (EF an OF, r spe tively)

6.3 Bus ac c es method

If two or mor nodes s art t o transmit DF s or RF s at the same time, the bus ac es conflct is r solved

b cont ent-b sed arbitration using the identif ie The me hanism of arbitration ensur s that neithe

information nor time is los The transmitt er with the DF or RF of the highes priority g ins the bus

ac es A DF with the same ID as an RF wins bus arbitration

6.4 Information r outing

A node does not make use of any information a out the network conf iguration (e.g node ad r s )

Inst ead, r c ive s ac ept or do not ac ept information b sed upon a proc s cal ed frame ac eptanc

filt ering, w hich de ides w hethe the r c ived information is r lev nt or not The e is no ne d for

r c ive s t o k ow the transmitt er of the information an vic ve sa

6.5 Networ k flex ibi ity

Nodes can be ad ed t o the CAN network without r q iring any chang e in the sof war or hardwar of

any node, if the ad ed node is not the transmitt er of any DF an if the ad ed node does not r q ir any

ad itional transmitt ed data

6.6 Data c onsistency

W ithin a CAN network, a frame can be simultaneously ac ept ed as a v ld frame eithe b al nodes

or b no node Th s data consist ency is a pro e ty of the CAN network achieved b the conc pt of

bro dcas an b e ror han l ng

6.7 Remote data request

By sending an RF, a node r q iring data ma r q es anothe node t o sen the cor esp n ing DF The

RF an the cor esp n ing DF ar named b the same identif ie

NOTE 1 The node having the mes a e with the req ested ID decides whether new data are prod ced or data

in a transmit bufer wil b sent

NOTE 2 The node having the mes a e with the req ested data decides how to respon to an RF with

mismatching DL

6.8 Error detection

F or det ecting e rors, the folowing measur s ar pro ided:

— monit oring ( ransmitt ers compar the transmitt ed bit levels with the bit levels det ect ed on the

network);

— 1 -bit CRC for Clas ical Frames, 1 -bit CRCfor FD Frames with up t o 1 data-f ield b t es, 2 -bit CRC

for FD Frames with 2 t o 64 data-f ield b t es;

— s uf bit count che k for FD Frames;

— v ria le bit tuffing with a s uf width of f ive (ex cept in the CRC field of FD Frames);

— frame format che k ;

— ACK che k

6.9 Error sig nal ing and rec over y time

Cor upt ed frames ar fla g ed b any transmit ing node an any normal y o e ating (e ror-active)

r c iving node Such frames ar a ort ed an r transmitt ed ac ording t o the implement ed r co e y

proc d r ( e 8.3.4) The r co e y time from det ecting an e ror u ti the p s ible s art of the next

frame is ty icaly 1 t o 2 nominal bit times ( in the case of nodes in e ror p s ive mode up t o 3 nominal

bit times), if the e ar no furthe e rors

6.10 ACK

Al r c ive s che k the consist ency of the r c ived DF s an RF s, acknow ledg e a consist ent frame,

an fla an inconsist ent frame b means of an EF A transmit ing node r g rds a DF or RF that is not

ack ow ledg ed as cor upt ed

6.11 Automatic retransmis ion

Frames that ha e los arbitration, frames that ha e not be n ack ow ledg ed, an frames that ha e be n

dis urbed b e rors d ring transmis ion ar r transmitt ed aut omaticaly u ti their transmis ion

has be n suc es fuly complet ed or u ti their transmis ion is no long er r q est ed ( e 8.3.4 an

1 9.6) Optionaly, the aut omatic r transmis ion ma be disa led ( e 9.3) Optionaly, the aut omatic

r transmis ion ma be l mit ed t o a c rtain n mbe of att empt ( e 1 9.6)

6.12 F ult c onfinement

CAN nodes ar a le t o dis inguish short dis urb nc s from pe manent faiur s Defe tive transmit ing

nodes ar swit ched of Swit ched of means a node is lo icaly discon e t ed from the bus, so that it can

neithe send nor r c ive any frames ( e 1 1.4.4)

6.13 Error-acti ve

An e ror-active node normaly takes p rt in bus commu ication an sen s an active e ror fla w hen an

e ror has be n det ect ed The active e ror fla consis s of 6 conse utive dominant bit an violat es the

rule of bit-s uff ing and al fix ed format a pearing in a DF an RF ( e 1 1.4.2)

6.14 Error-pas i ve

An e ror-pas ive node sends no active e ror fla It akes p rt in bus commu ication, but w hen an e ror

has be n det ect ed a pas ive e ror fla is sent The p s ive e ror fla consis s of 6conse utive r c s ive

bit Aft er transmis ion, an e ror-p s ive node wait some ad itional time befor initiating a furthe

transmis ion ( e suspen transmis ion in 1 4.6.4 an 1 1.4.2)

6.15 Bus-of

A node is in the bus-of s ate when it is switched of from the bus d e to a r q es of F E In the

bus-of s ate, a node neithe sen s nor r c ives frames In the bus-of s ate, a node does not sen any

dominant bit

7 Lay red architecture of CA N

7.1 Referenc e to OSI model

A ccording t o the OSI r fe enc model ( e ISO/IEC 749 -1), the CAN ar hit ectur of this p rt of

ISO 1 8 8 r pr sent two la e s ( e Figur 2),

— DL , an

— PCSof PL

Figure 2— Layered ar hitecture of CAN

A ccording t o ISO/IEC 8 0 - 2 an ISO/IEC 8 0 -3, the DLL is subdivided int o

The MAC sub-la e o e ations ar supe vised b the F E Fault conf inement is a self-che king

me hanism that dis inguishes short dis urb nc s from pe manent fai ur s ( e 1 1)

Optional y, the PL is supe vised b an entity that det ect an manag es fai ur s of the phy sical medium

(for ex mple, short ed or int er upt ed bus l nes, se 1 2)

7.2 Protoc ol specification

Two pe r prot ocol entities shal commu icat e with each othe b ex changing frames or PDUs

An ( N) la e Prot ocol Data Unit (PDU

N) consis s of (N) la e spe if ic prot ocol control information

(PCI

N) an (N) layer use data PDU

Nshal be p s ed t o a (N-1) la e entity via an SAP

N-1 The PDU

it r pr sent the lo ical data unit trans e r d b a se vic The DL of the CAN prot ocol shal pro ide

neithe means for ma ping one SDU int o multiple PDUs nor means for ma ping multiple SDUs int o

one PDU, i.e a PDU

Figure 3 — Protocol layer interactio s

7.3 F r mat des ription of ser vic es

7.3.1 F r mat des r iptio of ser vice primiti ves

S rvic primitives shal be writt en as:

indicat es the name of the se vic , e.g L_Data for data trans e se vic

pro ided b the L C sub-la e ;

type

indicat es the ty e of the se vic primitives ( e 7.3.2);

[par meter1,…]

isthe ls of v lues p s ed t o the se vic primitives

The bracket in icat e that this p ramet er ls ma be empty

7.3.2 T ypes of ser vic e primiti ves

S rvic primitives shal be of thr e g ene ic ty es

a) S rvic R eq es

The r q es primitive shal be pas ed from the ( N) use ( e vic use ) t o the ( N) layer ( e vic

pro ide ) t o r q es initiation of the se vic

b) S rvic In ication

The in ication primitive shal be pas ed from the (N) la e t o the (N) use t o in icat e an int ernal

( N) la e (or sub-la e ) event w hich is significant t o the (N) use This event ma be lo icaly r lat ed

t o a r mot e se vic r q es , or ma be ca used b an event int ernal t o the (N) la e (or sub-la e )

c) S rvic Confirm

The conf irm primitive shal be p s ed from the ( N) la e (or sub-la e ) t o the ( N) use t o convey

the r sult of one or mor as ociat ed pr vious se vic r q est (s) This primitive ma in icat e

eithe faiur t o comply or some level of complanc It shal not ne es ariy indicat e any activity at

the r mot e pe r int erfac

7.4 LL C inter fac e

The L Csub-la e shal ofe two ty esof conne tionles transmis ion se vic s t o the L C use :

— unacknow ledg ed data trans e se vic ;

— unacknow ledg ed r mot e data r q es se vic

The int erfac se vic data sent from or t o the use shal be as given in 8.2.2 The mes ag es sent betwe n

L Cuse an L C sub-la e ar spe if ied in Ta le 1 and Ta le 2

Table 1 — Mes ag e sent from LL user to L C sub- ayer

R eset_R eq est R eq est to set the node int o an initial state

Table 2 — Mes ag e sent from LL sub-aye to L C user

R eset_R esponse R esponse to the R eset_R eq est

Node_Status In icates the cur ent status of the node,i.e it signals whether or not the

node is in the bus-of state

The L Cint erfac mes ag es sent from and t o the supe visor F E shal be as spe ified in 1 1.3

8 Desc iption of LL C sub-layer

The L C sub-layer desc ibes the up e p rt of the DL ac ording t o ISO/IEC 8 0 - 2 It is as ociat ed with

those prot ocol is ues that ar in epen ent ofthe ty e of the medium ac es method

8.2 S rvic es of LL C sub- ayer

8.2.1 T ypes of c onnectionles -mo e transmis io servic es

The L Csub-la e shal ofe two ty es of conne tionles -mode transmis ion se vic s:

Unacknow ledg ed data transfe service

This se vic shal pro ide means b w hich L C use s ex chang e LSDU without es a l shing a data lnk

conne tion The data trans e ma be p int-t o-p int, multicas or bro dcas

Unacknow ledg ed remote data request service

This se vic shal pro ide means used b an LL use t o r q es a r mot e nodefor an LSDU transmis ion

without es a lshing a data ln con e tion

The r mot e node shal b sical y se ve the data r q es in the folowing two way s

— The r q est ed data ma be pr p r d b the r mot e use for transmis ion In this case, the data shal

be locat ed in a r mot e node bufe an shal be transmitt ed b the r mot e use L C entity up n

r c ption of the r mot e r q es frame

— The r ques ed data shal be transmit ed b the r mote use upon r c ption of the r mote

r q es frame

A ccording t o the two dife ent L C se vic s, six ty es of frames ma be used for the communication

betwe n transmit ing node and r c iving nodes

— LL Data Frame in Clas ical Base FrameF ormat ;

— LL Data Frame in Clas ical Ext ended FrameF ormat ;

— LL Data Frame in FD Base Frame F ormat ;

— LL Data Frame in FD Ext en ed Frame F ormat ;

— LL R emot e Frame in Clas ical Base Frame F ormat ;

— LL R emot e Frame in Clas ical Ext en ed Frame F ormat

The L C DF s shal car y data from a transmitt er t o a r c ive The L C RF s shal be transmitt ed t o

r q es transmis ion of a DF (with the same identif ie ) from a ( ingle) r mot e node In b th cases, the

L Csub-layer shal notify the suc es ful transmis ion or r c ption of a DF or RF t o the L C use

8.2.2 S r vic e primiti ve specificatio

8.2.2.1 General

The se vic primitive spe if ication of this sub-clause desc ibes in detai the L C se vic primitives an

their as ociat ed p ramet ers The complet e l s of LL se vic primitives shal be as given in Ta le3

Table 3 — L C service primitives overview

Unack owledg ed data transfer L_Data.R eq est R eq est or data transfer

L_Data.In ication In ication of data transfer

L_Data.Ab rtR eq est (optional) R eq est a ortion of data transfer

Unack owledg ed remote data

req est

L_R emot e.R eq est R eq est or remote data req est

L_R emot e.In ication In ication of remote data req est

L_R emot e.Conf irm Conf irmation remote data req est

L_R emot e.Ab rtR eq est

(option-al)

R eq est a ortion of remot e data

req est

The p ramet ers as ociat ed with the dife ent L C se vic primitives shal be as given in Ta le 4

Table 4 — List of L C service primitive parameter

Identif ier Identif ies the cont ent of the frame

Format Frame format (C F , C F , F F , F F , optionaly giving ESI an BRS bit values)

Data Data the user wants t o transmit

Transfer Status Conf irmation parameter

Han le (optional) Identif ies hardware element used for transaction

8.2.2.2 L_ Data.Request

F nctio

The L_Data.R eq es primitive shal be p s ed from the L C use t o the L C sub-la e t o r q es that an

LSDU be sent t o one or mor r mot e LL entities

S mantic of L_Data.Request primitive

The primitive shal pro ide p ramet ersas folows:

The p ramet er Data shal be insignif icant if the as ociat ed L C DF is of data length z ro Optionaly, the

hardwar element (mes ag e st orag e u it)t o be used for the transmis ion is identif ied b the Handle

Efect o receipt

R ec ipt of this primitive shal ca use the L C sub-la e t o initiat e the trans e of an L C DF b use of

the data trans e se vic pro ided b the MAC sub-la e ( e Ta le 6) Any L_Data.R eq es shal be

proc s ed not lat er than the se on SOF aft er the r q es w hen the e ar no e ror frames pr sent

d ring this time

8.2.2.3 L_ Data.indicatio

F nctio

The L_Data.In ication primitive shal be pas ed from the LL sub-la e t o the L C use t o in icat e the

ar iv l of an LSDU

S mantic of L_Data.Indicatio primitive

The primitive shal pro ide p ramet ersas folow s:

The L_Data.C nf irm primitive shal be p s ed from the local L C sub-la e t o the L C use t o convey

the r sult of the pr vious L_Data.R eq es primitive This primitive shal be a local confirmation, i.e it

shal not imply that the r mot e L C entity or entities ha ep s ed the as ociat ed in ication primitive t o

the cor esp n ing L C use ( )

S mantic of L_Data.Co firm primitive

The primitive shal pro ide p ramet ersas folow s:

The Trans e _Status shal be used t o in icat e the completion of the transaction s atus

— initiat ed b the pr vious L_Data.R eq es primitive ( if o tional Han le is not pr sent), or

— of the o tional y r fe r d hardwar element given b Han le

Trans e _Status:[Complet e, Not Complet e, Ab rt ed]

The trans e s atus Ab rted is a ai a le if the o tional se vic L_Data.AbortReques is pro ided

an supp rted

Efect o receipt

The efe t on r c ipt of thisprimitive b the L Cuse is u spe if ied

8.2.2.5 L_ Data.A bor tRequest (o tional

F nctio

The o tional L_Data.AbortR eq es primitive shal be pas ed from the L C use t o the L C sub-la e t o

a ort a r q es of transmis ion of an LSDU, w hich had be n r q est ed befor

S mantic of L_Data.AbortRequest primitive

The primitive shal pro ide p ramet ersas folows:

R ec ipt of this primitive shal cause the L C sub-la e t o a ort the trans e of an L CDF in the spe if ied

mes ag e st orag e u it Pen ing transmis ions, w hich alr ady ha e be n p s ed t o the MAC sub-la e ,

shal only bea ort ed if

— an e ror in the MACsub-la e d ring transmis ion oc urs, or

— arbitration was los in the MAC sub-la e ,

w hich causes the LSDU t o wait for anothe transmis ion att empt

This means that an a ortion r q es mus be kept pending in the L C la e u ti eithe one of the a o e

situations oc ur, or u ti the transmis ion was complet ed

The L C sub-la e cannot immediat ely a ort transmis ions w hich ha e alr ady be n submitt ed t o the

MAC sub-la e (d e t o priority sched l ng of the r q est ed hardwar element in icat ed b Han le) Any

L_Data.Ab rtR eq es shal be proc s ed prior t o the se on SOF aft er the r q es w hen the e ar no

e ror frames pr sent d ring this time Any L_Data.AbortR eq es shal be proc s ed prior t o the third

SOF aft er the r q es w hen the e ar e ror frames pr sent d ring this time

8.2.2.6 L_ Remote.Req est

F nctio

The L_R emot e.R eq es primitive shal be pas ed from the L C use t o the L C sub-la e t o r q es a

single r mot e L C entity t o transmit an LSDU

S mantic of L_Remote.Req est primitive

The primitive shal pro ide p ramet ersas folows:

The v lue of DL eq als the length of the data f ield of the r q est ed DF By the o tional Han le, the

hardwar element (mes ag e st orag e u it)t o be used for the transmis ion is identif ied

Efect o receipt

R ec ipt of this primitive shal cause the L C sub-la e t o initiat e the trans e of an LSDU in the o tionaly

spe ified mes ag e st orag e u it b use of the r mot e data trans e se vic pro ided b the MAC

sub-la e ( e Ta le 6)

8.2.2.7 L_ Remote.Indicatio

F nctio

The L_R emot e.In ication primitive shal be p s ed from the L C sub-la e t o the L C use t o in icat e

the ar iv l of a r q es for transmis ion of an LSDU

S mantic of L_Remote.Indication primitive

The primitive shal pro ide p ramet ersas folow s:

The L_R emot e.Conf irm primitive shal be pas ed from the local L C sub-la e t o the L C use t o convey

the r sult of the pr vious L_R emot e.R eq es primitive This primitive shal be a local conf irmation,

i.e it does not imply that the r mot e LL entity has p s ed the as ociat ed in ication primitive t o the

cor esp n ing L Cuse

S mantic of L_Remote.C nfirm primitive

The primitive shal pro ide p ramet ersas folow s:

The Trans e _Status shal be used t o in icat e the transaction s atus

— of the pr vious L_R emot e.R eq es primitive ( if o tional Han le isnot pr sent), or

— of the o tional y r fe r d hardwar element given b Han le

The Trans e _Status shal beused t o in icat e the completion of the transaction initiat ed b the pr vious

L_R emot e.R eq es primitive

Trans e _Status:[Complet e, Not_ Complet e, Ab rt ed]

The trans e s atus Not C mplet e shal be given w hen eithe a transmis ion r q es is s i pen ing or

ong oing, or if an o tional a ortion r q es ispen ing

If the o tional se vic L_R emot e.Ab rtR eq es is pro ided an sup ort ed, the trans e s atus Ab rt ed

is a aia le

Efect o receipt

The efe t on r c ipt of thisprimitive b the L Cuse is u spe if ied

8.2.2.9 L_ Remote.A bortRequest (optio al

F nctio

The o tional L_R emot e.Ab rtR eq es primitive shal be p s ed from the L C use t o the L C s

ub-la e t o a ort a r q es t o a single r mot e L C entity t o transmit an LSDU ( i.e an RF), w hich had be n

r q est ed befor

S mantic of L_Remote.AbortReq est primitive

The primitive shal pro ide p ramet ersas folows:

R ec ipt of this primitive shal cause the L C sub-la e t o a ort he trans e of an L CRF in the spe if ied

mes ag e st orag e u it Pen ing transmis ions, w hich alr ady ha e be n p s ed t o the MAC sub-la e ,

can only be a ort ed if

— an e ror in the MACsub-la e d ring transmis ion oc urs, or

— arbitration was los in the MAC sub-la e ,

w hich causes the LSDU t o wait for anothe transmis ion att empt

This means that an a ortion r q es mus be kept pen ing in the L C la e , u ti eithe one of the a o e

situations oc ur, or u ti the transmis ion was complet ed

The L C sub-la e cannot immediat ely a ort transmis ions w hich ha e alr ady be n submitt ed t o the

MAC sub-la e (d e t o priority sched lng of the r q est ed hardwar element in icat ed b theHan le)

8.3 Functions of LLC sub- ayer

8.3.1 General

The L Csub-la e shal pro ide the folowing functions:

— frame ac eptanc filt ering;

— o e lo d notification;

— r co e y manag ement

8.3.2 F rame ac c eptanc e fitering

A frame transaction initiat ed at the L C sub-la e shal be a single, self-contained o e ation indepen ent

of pr vious frame transactions The cont ent of a frame shal be named b it identif ie Each r c ive

shal de ide b frame ac eptanc filt ering w hethe the frame is r lev nt or not

8.3.3 Over load notification

The transmis ion of a MAC OF shal be initiat ed b the L C sub-la e if int ernal con itions of a r c ive

r q ir dela of the next LL DF or L C RF If the e ar int ernal con itions of a CAN implementation

that cause a MACOF t o be initiat ed, these con itions shal be document ed for that CANimplementation

A t mos , two MAC OF ma be g ene at ed t o dela the next DF or RF

8.3.4 Rec overy manag ement

The L C sub-la e shal pro ide means for a ut omatic r transmis ion of frames that los arbitration, that

ha e not be n ack ow ledg ed, or that ha e be n dis urbed b e rors d ring transmis ion Howeve , the

aut omatic r transmis ion can be a ort ed b the o tional L C Ab rtR eq es s The frame transmis ion

se vic shal not be r p rt ed as conf irmed or (o tionaly) a ort ed t o the use befor the transmis ion

has be n suc es ful y complet ed or (o tionaly) a ort ed The a ut omatic r transmis ion of a frame shal

be disa led w hen the transmis ion of that frame is no long er r q est ed The a ut omatic r transmis ion

ma be disa led for al frames

8.4 Structure of LLC frames

8.4.1 General

L C frames shal be the data unit ex chang ed betwe n pe r LL entities (LPDU) The s ructur an

format of the L C DF an RF shal be spe if ied subseq ently The o tional Han le of an L C frame

is kept within the L C it elf as a la el for use with up e la e commu ications Be ause of this, it

r pr sentation is invisible on the MACla e and th s invisible on the CAN bus In the folowing, the L C

frame Han le is no long er conside ed

The identif ie field shal be comp sed of two segment , the b se identif ie an the identif ie ext ension

The length of theb se identif ie shal be 1 bit (ID- 28 t o ID-1 ) an the length of the identifie ext ension

shal be 1 bit (ID-1 t o ID-0) The identifie ext ension shal be ignor d for frames in CBF an in FBF

8.4.2.3 F r mat field

This f ield dis inguishes betwe n frames in CBF , CEF , FBF , an FEF In FBF an FEF , it inclu es

the ESI bit an the BRS bit ( e Ta le 4)

8.4.2.4 DL C field

The n mbe of b t es in the data f ield shal be in icat ed b the DL ; se Ta le 5 This DL shal consis

of 4 bit The admis ible n mbe of data b t es for Clas ical Frames shal rang e from 0 t o 8 DL s in the

rang e of 0t o 7 shal in icat e data f ields of length of 0 b t e t o 7 b t e In Clas ical Frames, al othe DL s

shal in icat e that the data f ield is 8 b t e long In FD Frames, DL s in the rang e of 0 t o 8 shal in icat e

data f ields of length of 0 b t e t o 8 b t e, w hi e othe DL s code long er data f ields, ac ording t o Ta le 5

Table 5 — Coding of the number of data b tes by the DLC

The data f ield shal consis of the data t o be trans e r d within a DF It ma contain from 0 b t e t o 8

b t e in Clas ical Frames or it ma contain from 0 b t e t o 64 b t e in FD Frames, w he e each b t e shal

The format of b th the L CRF identifie field an DL f ield shal be identical t o the format ofthe L C

DF identifie f ield ( e 8.4.2.2) an DL f ield ( e 8.4.2.4) The e shal be no data field, in ependent of

the v lue of the DL The format f ield of an L C RF dis inguishes only betwe n frames in CBFF an

CEF The e shal be no L C RF in FBF or FEF

RF s shal only be transmitt ed with a network-wide det ermined DL , w hich is the DL of the

cor esp n ing DF ( e 1 9 9)

8.5 Limited LL C frames

It isnot r q ir d t o implement he ful rang e of p s ible identif ie sor DL s

If an L C sub-layer is r s rict ed t o the use of a sub-rang e of identifie s (e.g only 1 -bit identifie s), then

it shal be lmit ed t o L C DF s an L C RF s with identifie s of that sub-rang e (e.g identifie s with their

IDE bit set t o lo ic 0 an their identifie ext ension is ignor d)

If an L C sub-la e is r s rict ed t o the use of les than the ma imum n mbe of data b t es, then it shal

be l mit ed t o L CDF s with a n mbe of data b t es of that r s rict ed rang e If the DLC in icat es a highe

n mbe of data b t es, the data b t es beyon the r s rict ed rang e shal be r plac d in the L C DF b

b t es with the v lue of C

HE(“ pad ing” b th for r c ived an for transmitt ed frames Optionaly,

the CAN implementation ma sup ort a conf iguration w he e the CAN node wi not transmit a frame

w heneve the frame’ s DL in icat es a n mbe of data b t es bey n the r s rict ed rang e

NOTE T e pad ing for received mes ag es do s not ne d t o b implemented in the L C layer

9 Interfac e between LL C and MAC

9.1 S rvic es

The MAC sub-la e shal pro ide se vic s t o the local L C for

— (MAC- ack ow ledg ed trans e of L C frames, an

— transmis ion of MAC OF s

The int erfac se vic data from or t o the L Csub-la e shal be as desc ibed in 8.3

9.2 Time and time trig g er ing

9.2.1 Des ription

Optional y, CAN ena led implementations ma sup ort networ k-wide synchronization of clocks an if

so, they ma ad itionaly sup ort time-trigger d comm unication The clock synchronization o tion

desc ibes the pr r q isites ne ded for the algnment of node clocks in a networ k In orde to synchroniz

the clocks of the nodes within the networ k, a common r fe enc p int is ne ded The SOF bit or the sample

p int of the las bit of EOF of any mes age shal be used as the r fe enc p int Synchronization of node

clocks fa ci itates the es a l shment of a networ k-wide time b se in highe -la e protocols If implement ed,

the time trigger d comm unication o tion faci itates frames to be transmitt ed in defined time slot

The hardwar ne ded t o es a l sh a network-wide time b se shal be inclu ed betwe n LL an MAC

9.2.2 Time base

Any node that sup ort time an time trigg ering o tion shal pro ide a time b se The time b se is a cyclc

up cou t er of at leas 1 bit fed with clock ticks gene at ed b an int ernal or an ext ernal tick gene ator

9.2.3 Time referenc e point

Any mes ag e r c ived or transmitt ed shal invoke a ca tur of the time b se taken at the SOF

r co nition of the r spe tive mes ag e or at the sample point of the las bit of EOF Aft er suc es ful

mes ag e r c ption, the ca tur v lueshal be pro ided t o the CPU for at leas one mes ag e an shal be

r ada le u ti the next mes ag e is r c ived

9.2.4 E ent g eneratio

It shal be p s ible t o gene ate at leas one pro ramma le event trigg er from the a ove-mentioned

time b se The trigg er shal be fr ely pro ramma le b the CPU in the range of at leas z ro to

A ut omatic r transmis ion ma be disa led ( e 6.1 )

9.4 Mes ag e time stamping

Optional y, CAN FD ena led or not FD ena led implementations ma sup ort a mes ag e time s amping

fu ction for r c ived an transmitt ed data frames

The time-s amp shal ha e a width of 8 bit, 1 bit, or 3 bit The clock sour e for the time-b se shal be

g ene at ed int ernaly in the node or shal be pro ided b the L C use The time-base cou t er shal be

inc ement ed an shal o e run t o z ro

The time-b se cou t er ma be r ada le b the L C use at any time The time-b se v lue shal be

ca tur d at the r fe enc p int of each data frame F or Clas ical Frames, the r fe enc point is

the sample p int of SOF of the r spe tive frame or the p int-in-time w hen the frame is taken t o be

v ld ac ording t o 1 7 F or FD Frames, meaning w hen FDF is r c s ive an the subseq ent r s bit is

dominant, the r fe enc p int is thesample p int of SOF, or the sample point of the r s bit, or the p

oint-in time w hen the frame istaken t o be v ld ac ording t o 1 7

Aft er EOF, the ca tur d time-s amp v lue shal be r ada le b the L Cuse

10 Desc iption of MAC sub-layer

10.1 General

The MAC sub-la e r pr sent the lowe p rt of the OSI DL It shal se vic the int erfac t o the L C

sub-la e an the PL, an comprises the functions an rules r lat ed t o

— enca sulation/de-ca sulation of the transmit/r c ivedata,

— e ror det ection an signal ing, an

— manag ement of the transmit/r c ive medium ac es

10.2 S r vic es ofMAC sub- ayer

10.2.1 S rvic e des r iption

The se vic s pro ided b the MAC sub-la e shal alow the local L Csub-la e entity t o ex chang e MSDU

with the pe r L C sub-la e entities The MAC sub-la e se vic s shal be the fol owing:

a) acknow ledg ed data transfer

This se vic shal pro ide meansb w hich L Centities ex chang e MSDUs without the es a l shment

of a data lnk con e tion The data trans e ma be point-t o-point, multicas , or bro dcas

b) acknow ledg ed remote data request

This se vic shal pro ide means b w hich an L C entity r q es s anothe r mot e nodet o transmit

an LSDU without the es a lshment of a data lnk con e tion The r mot e L C entity shal use the

MAC se vic “ack ow ledg ed data trans e ” for the transmis ion of the r q est ed data ACK of a

se vic shal be g ene at ed b the MAC sub-la e ( ) of the r mot e node() ACK shal not contain any

data of the r mot e nodeuse

c) OF transfer

This se vic shal pro ide means b w hich an L C entity initiat es the transmis ion of an OF, a

spe ial f ix ed format LPDU, causing the dela of the next DF or RF

10.2.2 S rvic e primiti ves specificatio

10.2.2.1 General

The se vic primitives of the MAC sub-la e pro ided t o the L C sub-la e shal be as given in Ta le 6

Table 6 — MAC sub- ayer service primitives

data req est

MA_R emot e.R eq est

MA_R emot e.In ication

MA_R emot e.Conf irm

MA_OVLD.In ication

MA_OVLD.Conf irm

10.2.2.2 MA _Data.Req est

F nctio

The MA_Data.R eq es primitive shal be p s ed from the L Csub-la e t o the MAC sub-la e t o r q es

that an MSDU be sent t o one or mor r mot e MAC entities

S mantic of MA_Data.Request primitive

The primitive shal pro ide p ramet ersas folow s:

R ec ipt of this primitive shal cause the MAC sub-layer t o pr par a PDU b inclu ing al MAC spe if ic

control information ( SOF, SRR bit, IDE bit, R TR (or RRS) bit, FDF bit, r s (or r0) bit, BRS bit, ESI bit,

CRC, r c s ive bit d ring ACK f ield, EOF) t o the MSDU coming from the L C sub-la e F or detais, se

1 4.2.3 an 1 4.2.4 TheMPDU shal be se ialz d an p s ed bit b bit as an SDU t o the PL for trans e

t o the pe r MAC sub-la e entity or entities

10.2.2.3 MA _Data.Indicatio

F nctio

The MA_Data.In ication primitive shal be pas ed from the MAC sub-la e t o the L C sub-la e t o

in icat e the ar iv l of an MSDU

S mantic of MA_Data.Indicatio primitive

The primitive shal pro ide p ramet ersas folows:

The paramet er Data is insignif icant if the as ociat ed MAC DF is of data length z ro The ar iv l of an

MSDU shal be in icat ed t o the L C sub-la e only if it has be n r c ived cor e tly

Efect o receipt

The efe t on r c ipt of thisprimitive b the L Csub-la e is u spe ified

10.2.2.4 MA _Data.Co firm

F nctio

The MA_Data.C n rm primitive shal be p s ed from the local MAC sub-la e t o the L C sub-la e t o

convey the r sult of the pr vious MA_Data.R eq es primitive This primitive is a r mot e conf irmation,

i.e it shal in icat e that the r mot e MAC entity or entities ha e pas ed the as ociat ed in ication

primitive t o the cor esp n ing use ()

S mantic of MA_Data.Co firm primitive

The primitive shal pro ide p ramet ersas folows:

Transmis ion_Status:[ Suc es , No_Suc es ]

Faiur s ar eithe e rors w hich oc ur ed d ring transmis ion or los of arbitration

Efect o receipt

The efe t on r c ipt of thisprimitive b the L Csub-la e is u spe ified

10.2.2.5 MA _Remote.Request

F nctio

The MA_R emot e.R eq es primitive shal be pas ed from the L C sub-layer t o the MAC sub-la e t o

r q es a single r mot e MAC entity t o transmit an MSDU

S mantic of MA_Remote.Request primitive

The primitive shal pro ide p ramet ersas folows:

Re eipt of this primitive shal ca use the MAC sub-la e to pr p r a PDU b inclu ing al MAC spe ific

control information (SOF, SRR bit, IDE bit, RTR bit , FDF bit , r0 bit, CRC, r c s ive bit d ring ACK field,

EOF) to the MSDU coming from the L C sub-la ye For detai s, se 1 4.2.3 an 1 4.2.4 The MPDU shal be

se ialz d an p s ed bit b bit as an SDU to the PL for trans e to the pe r MAC sub-la e entity or entities

10.2.2.6 MA _Remote.Indication

F nctio

The MA_R emot e.In ication primitive shal be p s ed from the MAC sub-la e t o the L C sub-la e t o

in icat e the ar iv l of a r q es for transmis ion of an MSDU

S mantic of MA_Remote.Indication primitive

The primitive shal pro ide p ramet ersas folow s:

The ar iv l of an MSDU transmis ion r q es shal be indicat ed t o the L C sub-la e only if it has be n

r c ived cor e tly

Efect of receipt

The efe t of r c ipt on thisprimitive b the L Csub-la e is u spe if ied

10.2.2.7 MA _Remote.C nfirm

F nctio

The MA_R emot e.C n rm primitive shal be p s ed from the local MACsub-la e t o the L C sub-la e t o

convey the r sult of the pr vious MA_R emot e.R eq es This primitive is a r mot e con rmation, i.e it

shal in icat e that the r mot e MAC entity or entities ha e p s ed the as ociat ed in ication primitive t o

the cor esp n ing use ( )

S mantic of MA_Remote.C nfirm primitive

The primitive shal pro ide p ramet ersas folow s:

Transmis ion_Status:[ Suc es , No_Suc ess ]

Faiur s ar eithe e rors w hich oc ur ed d ring transmis ion or los of arbitration

Efect o receipt

The efe t on r c ipt of thisprimitive b the L Csub-la e is u spe ified

10.2.2.8 MA _OVLD.Request

F nctio

The MA_ OVLD.R eq es primitive shal be pas ed from the L C sub-la e t o the MAC sub-la e t o

r q es transmis ion of a MAC OVLD frame ( e 1 4.5) The OVLD frame shal be a fix ed format frame

an complet ely cons ruct ed in the MAC sub-la e

S mantic of MA_ OVLD.Req est primitive

The primitive shal not pro ide any p ramet er:

M _OVL r qu s (

)

Efect o receipt

R ec ipt of this primitive shal ca use the MAC sub-la e t o form an OF The OF shal be p s ed t o the

lowe prot ocol la e s for trans e t o thepe r MAC sub-la e entities

10.2.2.9 MA _OVLD.Indication

F nctio

The MA_ OVLD.In ication primitive shal be p s ed from the MAC sub-la e t o the L C sub-la e t o

in icat e that an OF has be n r c ived ( e 1 4.5)

S mantic of MA_ OVLD.Indicatio primitive

The primitive shal not pro ide any p ramet ers:

The MA_ OVLD.C nf irm primitive shal be p s ed from the MAC sub-la e t o the L C sub-la e t o

in icat e that an OF has be n sent This con rmation shal be local, i.e it hal not imply that the r mot e

pe r prot ocol entities ha e r c ived the OF cor e tly

S mantic of MA_ OVLD.Co firm primitive

The primitive shal pro ide p ramet ersas folows

Efect o receipt

The efe t on r c ipt of thisprimitive b the L Csub-la e is u spe if ied

10.3 Functional model of MAC sub- ayer ar chitecture

10.3.1 Capabi ity

The fu ctional ca a i ities of the MAC sub-la e ar desc ibed b use of the functional model

spe if ied in ISO/IEC 88 2-3 ( e also Figur 6) In this model, the MAC sub-la e is divided int o two

ful y in epen ently-o e ating part , i.e the transmit p rt an the r c ive p rt The functions of b th

transmit an r c ive p rt shal be as given in this clause an Figur 6

10.3.2 F rame transmis io

Frame transmis ion shal fulf il the folowing r q ir ment :

a) Transmit data enca sulation

— ac eptanc of L Cframes an int erfac control information;

— CRC seq enc calculation inclu ing s uf bit cou t for FD Frames;

— cons ruction of MAC frame b ad ing SOF, SRR bit ( if used in frame format), IDE bit, R TR (or

RRS)bit, FDF bit, r s bit, BRSbit ( if used in frame format), ESI bit ( if used in frame format), CRC,

ACK an EOF t o the L C frame (r s rict ed L C sub-la e s ma not r q es the transmis ion of

MAC frames with identif ie s or data f ields out ide their r s rictions; se 8.5)

b) Transmit medium ac es manag ement

— initiation of the transmis ion proc s afte r co nizing bus idle (compl anc with inter

-frame space);

— se ialzation of the MAC frame;

— inse tion of s uf bit (bit tuff ing);

— arbitration and pas ing int o r c ive mode in caseof los of arbitration;

— e ror det ection (monit oring, format che k);

— ACK che k ;

— r co nition of an o e lo d con ition;

— OF cons ruction an initiation of transmis ion;

— EF cons ruction an initiation of transmis ion;

— pr sentation of a se ial bit s r am t o the PL for transmis ion

Figure 6 — MAC functio s

10.3.3 F rame r ec eption

Frame r c ption shal fulfil the folowing r q ir ment :

a) R ec ive medium ac es manag ement:

— r c ption of a se ial bit s r am from the PL;

— dese ialzation an r compi ing of the frame s ructur ;

— deletion of s uf bit (bit de-s uffing);

— e ror det ection (CRC, s uf bit count che k, format che k, s uf rule che k);

— transmis ion of ACK;

— EF cons ruction an initiation of transmis ion;

— r co nition of an o e lo d con ition;

— r active OF cons ruction and initiation of transmis ion

b) R ec ive data de-ca sulation

— r mo ing the MAC spe if ic information from the r c ived frame;

— pr senting the L Cframe an int erfac control information t o the L C sub-la e (for r s rict ed

L Csub-la e s only l mit ed p rt of theL Cframe ar pr sent ed; se 8.5)

10.4 Structure of MAC frames

10.4.1 Des ription

Data transmis ion an r c ption betwe n nodes in a CAN network shal be pe formed and controled

b four dife ent frame ty es:

— a DF that car ies data from a transmitt er t o al r c ive s;

— an RF transmitt ed b a node for r q es ing transmis ion of the DF with the same identif ie ;

— an EF transmitt ed b any node ( ransmitt er or r c ive ) in case of a buse ror det ect ed;

— an OF used for pro iding an extra dela betwe n the pr c ding and suc e ding DF s or RF s

DFs and RFs shal arbitrate for bus ac es an shal be separated from pr c ding frames b an

inte -frame spac

The e ar four dife ent DF s in CAN:

— DF in Clas ical Base Frame F ormat,

— DF in Clas ical Ext en ed Frame F ormat,

— DF in FD Base Frame F rmat,

— DF in FD Ext en ed Frame F ormat

The e ar two dife ent RF s in CAN:

— RF in Clas ical Base Frame F ormat,

— RF in Clas ical Ext en ed Frame F ormat

10.4.2 Specificatio of MAC DF

10.4.2.1 Des riptio

On transmis ion, an L CDF ( e Figur 4) shal be conve t ed into a MACDF On r c ption, a MAC DF shal

be conve ted int o an L C DF MAC DF s shal be comp sed of seven dife ent bit fields; se also Figur 7

— SOF ;

— arbitration f ield (contains identifie f ield an p rt of format f ield);

— control field (contains DL f ield an p rt of format field);

— data field (contains L C data field);

— CRC f ield;

— ACK f ield;

— EOF

Figure 7 — MAC DF