Road vehicles -- Clock extension peripheral interface (CXPI)

This document specifies the conformance test plans for the CXPI data link layer and the CXPI physical layer. It also specifies the conformance test plan for error detection. Additionally, this document describes the concept of conformance test plan operation.

Véhicules routiers -- Interface périphérique d’extension d'horloge (CXPI)

General Information

Status
Published
Publication Date
29-Oct-2020
Current Stage
5060 - Close of voting Proof returned by Secretariat
Start Date
16-Sep-2020
Completion Date
16-Sep-2020
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INTERNATIONAL ISO
STANDARD 20794-7
First edition
2020-10
Road vehicles — Clock extension
peripheral interface (CXPI) —
Part 7:
Data link and physical layer
conformance test plan
Véhicules routiers — Interface périphérique d’extension d'horloge
(CXPI) —
Partie 7: Plan de test de conformité des couches de liaison de données
et physique
Reference number
ISO 20794-7:2020(E)
ISO 2020
---------------------- Page: 1 ----------------------
ISO 20794-7:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting

on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address

below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 20794-7:2020(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................vi

Introduction ..............................................................................................................................................................................................................................vii

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Symbols and abbreviated terms ........................................................................................................................................................... 1

4.1 Symbols ......................................................................................................................................................................................................... 1

4.2 Abbreviated terms ............................................................................................................................................................................... 2

5 Conventions ............................................................................................................................................................................................................... 3

6 General test specification considerations .................................................................................................................................. 3

6.1 General ........................................................................................................................................................................................................... 3

6.2 Test conditions ........................................................................................................................................................................................ 4

6.3 IUT requirements.................................................................................................................................................................................. 4

6.4 CTC definition .......................................................................................................................................................................................... 4

6.5 Test system set-up ................................................................................................................................................................................ 5

6.6 Configuration of test system and IUT .................................................................................................................................. 6

6.6.1 General...................................................................................................................................................................................... 6

6.6.2 IUT-specific set-up parameters ........................................................................................................................... 7

6.6.3 Default configurations ................................................................................................................................................. 8

6.6.4 L_ErrDet1 configurations ......................................................................................................................................... 8

6.6.5 L_ErrDet2 configurations ......................................................................................................................................... 8

6.6.6 L_Arbit configurations ........................................................................................................................................... ...... 8

6.6.7 L_Unknown configurations ..................................................................................................................................... 8

6.7 SUT initialisation ................................................................................................................................................................................... 8

6.8 Additional test system set-up capabilities ...................................................................................................................... 9

6.8.1 CXPI network data generator ................................................................................................................................ 9

6.8.2 TXD data generator ....................................................................................................................................................11

6.8.3 TX data generator ..............................................................................................................................................13

PWM

6.8.4 RX data generator ..............................................................................................................................................14

PWM

6.8.5 Other requirements ....................................................................................................................................................16

7 Data link layer conformance test plan ........................................................................................................................................16

7.1 General ........................................................................................................................................................................................................16

7.2 CTP – Timing parameters ...........................................................................................................................................................16

7.2.1 2.CTC_1.1 – IBS length ..............................................................................................................................................16

7.2.2 2.CTC_1.2 – IFS length ..............................................................................................................................................17

7.2.3 2.CTC_1.3 – Frame reception starting condition 1 without the error bit .....................18

7.2.4 2.CTC_1.4 – Frame reception starting condition 1 with the error bit .............................18

7.2.5 2.CTC_1.5 – Frame reception starting condition 2 without the error bit .....................19

7.2.6 2.CTC_1.6 – Frame reception starting condition 2 with the error bit .............................20

7.2.7 2.CTC_1.7 – Frame reception starting condition 3 ...........................................................................20

7.2.8 2.CTC_1.8 – Maximum length of the frame .............................................................................................21

7.3 CTP – Frame transmission/reception ..............................................................................................................................22

7.3.1 2.CTC_2.1 – Response to L_PID field.............................................................................................................22

7.3.2 2.CTC_2.2 – L_PID field transmission ..........................................................................................................23

7.3.3 2.CTC_2.3 – L_PTYPE field transmission ..................................................................................................23

7.3.4 2.CTC_2.4 – L_PTYPE field response function ......................................................................................24

7.3.5 2.CTC_2.5 – L_FI_DLC ≠ 1111 and frame data verification 1.................................................25

7.3.6 2.CTC_2.6 – L_FI_DLC ≠ 1111 and frame data verification 2 if DLC is

1101 or 1110 (Ftype = NormalCom) ......................................................................................................26

2 2

7.3.7 2.CTC_2.7 – L_FI_DLC = 1111 /L_FI_DLCext ≥ 0 and frame data verification ..........27

7.3.8 2.CTC_2.8 – Given CRC of frame with L_FI_DLC ≠ 1111 ...........................................................28

7.3.9 2.CTC_2.9 – Given CRC of frame with L_FI_DLC = 1111 /L_FI_DLCext ≥ 0 .................29

© ISO 2020 – All rights reserved iii
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ISO 20794-7:2020(E)

7.3.10 2.CTC_2.10 – Frame transmission completion ....................................................................................30

7.3.11 2.CTC_2.11 – Frame reception completion .............................................................................................30

7.4 CTP – Network access ....................................................................................................................................................................31

7.4.1 2.CTC_3.1 – Arbitration function 1 (arbitration by using carrier sense) ......................31

7.4.2 2.CTC_3.2 – Arbitration function 2 (IUT loses arbitration and transitions

into receiving state)....................................................................................................................................................32

7.5 CTP – Error detection .....................................................................................................................................................................33

7.5.1 2.CTC_4.1 – Byte error ..............................................................................................................................................33

7.5.2 2.CTC_4.2 – CRC error ...............................................................................................................................................35

7.5.3 2.CTC_4.3 – Parity error of the L_PID field without the error bit ........................................36

7.5.4 2.CTC_4.4 – Parity error of the L_PID field with the error bit ................................................37

7.5.5 2.CTC_4.5 – Parity error of the L_PTYPE field without the error bit ................................37

7.5.6 2.CTC_4.6 – Parity error of the L_PTYPE field with the error bit ........................................38

7.5.7 2.CTC_4.7 – Data length code error with L_FI_DLC ≠ 1111 ..................................................39

7.5.8 2.CTC_4.8 – Data length error with L_FI_DLC = 1111 /L_FI_DLCext ≥ 0 ......................40

7.5.9 2.CTC_4.9 – Data length code error L_FI_DLC ≠ 1111 and if DLC is 1101
2 2

or 1110 (Ftype = DiagNodeCfg) ....................................................................................................................41

7.5.10 2.CTC_4.10 – Data length code error L_FI_DLC = 1111 /L_FI_DLCext ≤ 12

(Ftype = DiagNodeCfg) ............................................................................................................................................42

7.5.11 2.CTC_4.11 – Framing error in receiving node ....................................................................................43

7.5.12 2.CTC_4.12 – Framing error in transmitting node ...........................................................................44

7.5.13 2.CTC_4.13 – Ignore error (no support of L_FI_DLC = 1111 ) ...............................................44

8 Physical layer conformance test plan (PMA – PS separate type) .....................................................................45

8.1 CTP – Operational conditions and calibration ..........................................................................................................45

8.1.1 Initial configuration....................................................................................................................................................45

8.1.2 1.CTC_1.1 – Clock transmission 1 ...................................................................................................................46

8.1.3 1.CTC_1.2 – Clock transmission 2 ...................................................................................................................47

8.1.4 1.CTC_1.3 – Clock transmission 3 ...................................................................................................................49

8.1.5 1.CTC_1.4 – Detection of clock existence ..................................................................................................51

8.1.6 1.CTC_1.5 – Arbitration function (stop transmission by arbitration) .............................52

8.1.7 1.CTC_1.6 – Operating voltage range ...........................................................................................................54

8.1.8 1.CTC_1.7 – Bit synchronisation ......................................................................................................................55

8.2 CTP – Wake-up pulse ......................................................................................................................................................................57

8.2.1 General...................................................................................................................................................................................57

8.2.2 1.CTC_2.1 – Wake-up pulse reception 1, IUT as master node ................................................57

8.2.3 1.CTC_2.2 – Wake-up pulse reception 2, IUT as slave node .....................................................59

8.2.4 1.CTC_2.3 – Wake-up pulse transmission ................................................................................................61

8.3 CTP – Voltage and duty cycle thresholds .......................................................................................................................63

8.3.1 General...................................................................................................................................................................................63

8.3.2 Voltage threshold test set-up .............................................................................................................................63

8.3.3 1.CTC_3.1 – Voltage threshold test 1 ............................................................................................................63

8.3.4 1.CTC_3.2 – Voltage threshold (V up) test 2 ...........................................................................64

Dom_TS

8.3.5 1.CTC_3.2 – Voltage threshold test 2 ............................................................................................................66

8.3.6 1.CTC_3.3 – Duty cycle threshold test 1 ....................................................................................................67

8.3.7 1.CTC_3.4 – Duty cycle threshold test 2 ....................................................................................................68

8.4 CTP – Network state current characteristics .............................................................................................................69

8.4.1 1.CTC_4.1 – Drive current test ...........................................................................................................................69

8.4.2 1.CTC_4.2 – Input leakage test ...........................................................................................................................71

8.4.3 1.CTC_4.3 – Reverse leakage current test ................................................................................................72

8.5 CTP – Physical signal slope control ....................................................................................................................................73

8.5.1 1.CTC_5.1 – Duty cycle measurement 1 .....................................................................................................73

8.5.2 1.CTC_5.2 – Duty cycle measurement 2 .....................................................................................................75

8.5.3 1.CTC_5.3 – Duty cycle measurement 3 .....................................................................................................77

8.5.4 1.CTC_5.4 – Propagation delay of the receiver test .........................................................................78

8.5.5 1.CTC_5.5 – Propagation delay of the transmitter test .................................................................80

8.5.6 1.CTC_5.6 – Propagation delay of the transmitter test 2 ............................................................82

8.5.7 1.CTC_5.7 – Loop back time test ......................................................................................................................84

8.6 CTP – GND/V shift test ..........................................................................................................................................................85

BAT
iv © ISO 2020 – All rights reserved
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ISO 20794-7:2020(E)

8.6.1 GND/V shift test set-up ...................................................................................................................................85

BAT

8.6.2 1.CTC_6.1 – GND shift test .....................................................................................................................................86

8.6.3 1.CTC_6.2 – V shift test .....................................................................................................................................87

BAT

8.7 CTP – Loss of power supply ......................................................................................................................................................88

8.7.1 Loss of battery and Loss of GND test set-up .................. ........................................................................88

8.7.2 1.CTC_7.1 – Loss of battery test (V ) ......................................................................................................89

BAT

8.7.3 1.CTC_7.2 – Loss of GND test ..............................................................................................................................90

8.8 CTP – Internal static capacity ..................................................................................................................................................91

8.8.1 Internal static capacity test set-up ................................................................................................................91

8.8.2 1.CTC_8.1 Internal static capacity ..................................................................................................................92

8.9 CTP – Internal resistance measurement during operation ...........................................................................94

8.9.1 Internal resistor measurement test set-up ............................................................................................94

8.9.2 1.CTC_9.1– Internal resistor measurement 1 .......................................................................................95

8.9.3 1.CTC_9.2– Internal resistor measurement 2 .......................................................................................96

9 Physical layer conformance test plan (PS –PMA non-separate type) ..........................................................97

9.1 CTP – Operational conditions and calibration ..........................................................................................................97

9.1.1 1.CTC_10.1 – Clock transmission ....................................................................................................................97

9.1.2 1.CTC_10.2 – Detection of clock existence ..............................................................................................99

9.1.3 1.CTC_10.3 – Arbitration function (stop transmission by arbitration) .......................100

9.1.4 1.CTC_10.4 – Operating voltage range .....................................................................................................101

9.2 CTP – Wake-up pulse ...................................................................................................................................................................102

9.2.1 General................................................................................................................................................................................102

9.2.2 1.CTC_11.1 – Wake-up pulse reception, IUT as master node ...............................................102

9.2.3 1.CTC_11.2 – Wake-up by clock detection ............................................................................................103

9.2.4 1.CTC_11.3 – Wake-up pulse transmission..........................................................................................104

9.3 CTP – Voltage and duty cycle thresholds ....................................................................................................................105

9.3.1 General................................................................................................................................................................................105

9.3.2 1.CTC_12.1 – Voltage threshold test 1 ......................................................................................................105

9.3.3 1.CTC_12.2 – Voltage threshold test 2 ......................................................................................................107

9.3.4 1.CTC_12.3 – Duty cycle threshold test 1 ..............................................................................................108

9.3.5 1.CTC_12.4 – Duty cycle threshold test 2 ..............................................................................................111

9.4 CTP – Network state current characteristics ..........................................................................................................112

9.4.1 1.CTC_13.1 – Drive current test .....................................................................................................................112

9.4.2 1.CTC_13.2 – Input leakage test ....................................................................................................................114

9.4.3 1.CTC_13.3 – Reverse leakage current test ..........................................................................................115

9.5 CTP – Physical signal slope control .................................................................................................................................116

9.5.1 1.CTC_14.1 – Duty cycle measurement 1 ..............................................................................................116

9.5.2 1.CTC_14.2 – Duty cycle measurement 2 ..............................................................................................118

9.6 CTP – GND/V shift test .......................................................................................................................................................120

BAT

9.6.1 GND/V shift test set-up ................................................................................................................................120

BAT

9.6.2 1.CTC_15.1 – GND shift test...............................................................................................................................121

9.6.3 1.CTC_15.2 – V shift test ...............................................................................................................................122

BAT

9.7 CTP – Loss of power supply ...................................................................................................................................................123

9.7.1 General................................................................................................................................................................................123

9.7.2 Loss of battery (V ) and GND test set-up ........................................................................................123

BAT

9.7.3 1.CTC_16.1 – Loss of battery test (V ) ................................................................................................124

BAT

9.7.4 1.CTC_16.2 – Loss of GND test ........................................................................................................................125

9.8 CTP – Internal static capacity ...............................................................................................................................................126

9.8.1 Internal static capacity test set-up .............................................................................................................126

9.8.2 1.CTC_17.1 Internal static capacity ............................................................................................................127

9.9 CTP – Internal resistance measurement during operation ........................................................................129

9.9.1 Internal resistor measurement test set-up .........................................................................................129

9.9.2 1.CTC_18.1– Internal resistor measurement 1 ................................................................................130

9.9.3 1.CTC_18.2– Internal resistor measurement 2 ................................................................................131

Bibliography .........................................................................................................................................................................................................................133

© ISO 2020 – All rights reserved v
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ISO 20794-7:2020(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www .iso .org/ patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to

the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see

www .iso .org/ iso/ foreword .html.

This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 31,

Data communication.
A list of all parts in the ISO 20794 series can be found on the ISO website.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www .iso .org/ members .html.
vi © ISO 2020 – All rights reserved
---------------------- Page: 6 ----------------------
ISO 20794-7:2020(E)
Introduction

ISO 20794 (all parts) specifies the application (partly), application layer, transport layer, network

lay
...

DRAFT INTERNATIONAL STANDARD
ISO/DIS 20794-7
ISO/TC 22/SC 31 Secretariat: DIN
Voting begins on: Voting terminates on:
2019-11-13 2020-02-05
Road vehicles — Clock extension peripheral interface
(CXPI) —
Part 7:
Data link and physical layer conformance test plan
Véhicules routiers — Interface périphérique d’extension d'horloge (CXPI) —

Partie 7: Plan de test de conformité des couches de liaison de données et physique

ICS: 43.040.15
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
This document is circulated as received from the committee secretariat.
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 20794-7:2019(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION. ISO 2019
---------------------- Page: 1 ----------------------
ISO/DIS 20794-7:2019(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2019

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting

on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address

below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/DIS 20794-7:2019(E)
Contents Page

Foreword ........................................................................................................................................................................ vii

Introduction ................................................................................................................................................................. viii

1 Scope ..................................................................................................................................................................1

2 Normative references ..................................................................................................................................1

3 Terms and definitions .................................................................................................................................2

4 Symbols and abbreviated terms ..............................................................................................................2

4.1 Symbols .............................................................................................................................................................2

4.2 Abbreviated terms ........................................................................................................................................3

5 Conventions.....................................................................................................................................................4

6 General test specification considerations ............................................................................................5

6.1 Data link layer conformance test ............................................................................................................5

6.1.1 General ..............................................................................................................................................................5

6.1.2 Test conditions ...............................................................................................................................................5

6.1.3 IUT requirements ..........................................................................................................................................5

6.1.4 CTC definition .................................................................................................................................................5

6.1.5 Test system set-up ........................................................................................................................................6

6.1.6 Configuration of test system and IUT .....................................................................................................6

6.1.7 SUT initialisation ...........................................................................................................................................9

6.2 Physical layer conformance test ........................................................................................................... 10

6.2.1 CTC definition .............................................................................................................................................. 10

6.2.2 Requirements to measurement system ............................................................................................. 10

6.2.3 SUT initialisation ........................................................................................................................................ 18

7 Data link layer conformance test plan ............................................................................................... 19

7.1 General ........................................................................................................................................................... 19

7.2 CTP – Timing parameters ........................................................................................................................ 19

7.2.1 2.CTC_1.1 – IBS length ............................................................................................................................... 19

7.2.2 2.CTC_1.2 – IFS length ............................................................................................................................... 21

7.2.3 2.CTC_1.3 – Frame reception starting condition 1 ......................................................................... 22

7.2.4 2.CTC_1.4 – Frame reception starting condition 2 ......................................................................... 23

7.2.5 2.CTC_1.5 – Frame reception starting condition 3 ......................................................................... 24

7.2.6 2.CTC_1.6 – Maximum length of the frame ........................................................................................ 25

7.3 CTP – Frame transmission/reception ................................................................................................. 26

7.3.1 2.CTC_2.1 – Response to L_PID field ..................................................................................................... 26

7.3.2 2.CTC_2.2 – L_PID field transmission ................................................................................................... 27

7.3.3 2.CTC_2.3 – L_PTYPE field transmission ............................................................................................. 28

7.3.4 2.CTC_2.4 – L_PTYPE field response function ................................................................................... 28

7.3.5 2.CTC_2.5 – L_FI_DLC ≠ 1111 and frame data verification 1 ...................................................... 30

7.3.6 2.CTC_2.6 – L_FI_DLC ≠ 1111 and frame data verification 2 if DLC is 1101 or 1110

2 2 2

(Ftype = NormalCom) ............................................................................................................................... 31

7.3.7 2.CTC_2.7 – L_FI_DLC = 1111 / L_FI_DLCext ≥ 0 and frame data verification ....................... 33

7.3.8 2.CTC_2.8 – Given CRC of frame with L_FI_DLC ≠ 1111 ................................................................ 34

7.3.9 2.CTC_2.9 – Given CRC of frame with L_FI_DLC = 1111 / L_FI_DLCext ≥ 0 ............................. 35

7.3.10 2.CTC_2.10 – Frame transmission completion ................................................................................. 36

© ISO 2019 – All rights reserved
iii
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ISO/DIS 20794-7:2019(E)

7.3.11 2.CTC_2.11 – Frame reception completion ....................................................................................... 38

7.4 CTP – Network access ............................................................................................................................... 40

7.4.1 2.CTC_3.1 – Arbitration function 1 (arbitration by using carrier sense) ............................... 40

7.4.2 2.CTC_3.2 – Arbitration function 2 (IUT loses arbitration and transitions into

receiving state) ........................................................................................................................................... 41

7.5 CTP – Error detection ............................................................................................................................... 42

7.5.1 2.CTC_4.1 – Byte error .............................................................................................................................. 42

7.5.2 2.CTC_4.2 – CRC error ............................................................................................................................... 44

7.5.3 2.CTC_4.3 – Parity error of the PID field ............................................................................................ 46

7.5.4 2.CTC_4.4 – Parity error of the L_TYPE field ..................................................................................... 47

7.5.5 2.CTC_4.5 –Data length code error with L_FI_DLC ≠ 1111 ......................................................... 48

7.5.6 2.CTC_4.6 – Data length error with L_FI_DLC = 1111 / L_FI_DLCext ≥ 0 ................................ 50

7.5.7 2.CTC_4.7 – Data length code error L_FI_DLC ≠ 1111 and if DLC is 1101 or 1110

2 2 2

(Ftype = DiagNodeCfg) ............................................................................................................................. 52

7.5.8 2.CTC_4.8 – Data length code error L_FI_DLC = 1111 / L_FI_DLCext ≤ 12 (Ftype =

DiagNodeCfg) ............................................................................................................................................... 53

7.5.9 2.CTC_4.9 – Framing error in receiving node .................................................................................. 54

7.5.10 2.CTC_4.10 – Framing error in transmitting node ......................................................................... 55

7.5.11 2.CTC_4.11 – Ignore error (no support of L_FI_DLC = 1111 ) ..................................................... 56

8 Physical layer conformance test plan (PMA – PS separate type) ............................................. 58

8.1 General .......................................................................................................................................................... 58

8.2 CTP – Operational conditions and calibration ................................................................................ 58

8.2.1 Initial configuration .................................................................................................................................. 58

8.2.2 1.CTC_1.1 – Clock transmission 1 ......................................................................................................... 59

8.2.3 1.CTC_1.2 – Clock transmission 2 ......................................................................................................... 61

8.2.4 1.CTC_1.3 – Clock transmission 3 ......................................................................................................... 63

8.2.5 1.CTC_1.4 – Detection of clock existence ........................................................................................... 65

8.2.6 1.CTC_1.5 – Arbitration function (stop transmission by arbitration) .................................... 67

8.2.7 1.CTC_1.6 – Operating voltage range .................................................................................................. 69

8.2.8 1.CTC_1.7 – Bit synchronisation ........................................................................................................... 71

8.3 CTP – Wake-up pulse ................................................................................................................................ 73

8.3.1 General .......................................................................................................................................................... 73

8.3.2 1.CTC_2.1 – Wake-up pulse reception 1, IUT as master node .................................................... 73

8.3.3 1.CTC_2.2 – Wake-up pulse reception 2, IUT as slave node ........................................................ 75

8.3.4 1.CTC_2.3 – Wake-up pulse transmission ......................................................................................... 77

8.4 CTP – Voltage and duty cycle thresholds ........................................................................................... 79

8.4.1 General .......................................................................................................................................................... 79

8.4.2 Voltage threshold test set-up ................................................................................................................ 79

8.4.3 1.CTC_3.1 – Voltage threshold test 1 ................................................................................................... 80

8.4.4 1.CTC_3.2 – Voltage threshold test 2 ................................................................................................... 82

8.4.5 1.CTC_3.3 – Duty cycle threshold test 1.............................................................................................. 85

8.4.6 1.CTC_3.4 – Duty cycle threshold test 2.............................................................................................. 87

8.5 CTP – Network state current characteristics ................................................................................... 88

8.5.1 1.CTC_4.1 – Drive current test ............................................................................................................... 88

8.5.2 1.CTC_4.2 – Input leakage test ............................................................................................................... 90

8.5.3 1.CTC_4.3 – Reverse leakage current test ......................................................................................... 92

8.6 CTP – Physical signal slope control ..................................................................................................... 94

8.6.1 1.CTC_5.1 – Duty cycle measurement 1 .............................................................................................. 94

8.6.2 1.CTC_5.2 – Duty cycle measurement 2 .............................................................................................. 96

8.6.3 1.CTC_5.3 – Duty cycle measurement 3 .............................................................................................. 98

8.6.4 1.CTC_5.4 – Propagation delay of the receiver test...................................................................... 100

8.6.5 1.CTC_5.5 – Propagation delay of the transmitter test ............................................................... 102

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8.6.6 1.CTC_5.6 – Propagation delay of the transmitter test 2 ........................................................... 104

8.6.7 1.CTC_5.7 – Loop back time test ......................................................................................................... 106

8.7 CTP – GND / V shift test .................................................................................................................... 108

BAT

8.7.1 GND / V shift test set-up ................................................................................................................... 108

BAT

8.7.2 1.CTC_6.1 – GND shift test ..................................................................................................................... 109

8.7.3 1.CTC_6.2 – V shift test ...................................................................................................................... 110

BAT

8.8 CTP – Loss of power supply ................................................................................................................. 111

8.8.1 General ........................................................................................................................................................ 111

8.8.2 Loss of battery (V ) and GND test set-up ..................................................................................... 111

BAT

8.8.3 1.CTC_7.1 – Loss of battery test (V ) .............................................................................................. 112

BAT

8.8.4 1.CTC_7.2 – Loss of GND test ................................................................................................................ 113

8.9 CTP – Internal static capacity.............................................................................................................. 115

8.9.1 Internal static capacity test set-up .................................................................................................... 115

8.9.2 1.CTC_8.1 Internal static capacity ..................................................................................................... 115

8.10 CTP – Internal resistance measurement during operation ..................................................... 118

8.10.1 Internal resistor measurement test set-up ................................................................................... 118

8.10.2 1.CTC_9.1– Internal resistor measurement 1 ................................................................................ 120

8.10.3 1.CTC_9.2– Internal resistor measurement 2 ................................................................................ 121

9 Physical layer conformance test plan (PS –PMA non separate type) ................................... 122

9.1 General ........................................................................................................................................................ 122

9.2 CTP – Operational conditions and calibration.............................................................................. 122

9.2.1 1.CTC_10.1 – Clock transmission ....................................................................................................... 122

9.2.2 1.CTC_10.2 – Detection of clock existence ...................................................................................... 125

9.2.3 1.CTC_10.3 – Arbitration function (stop transmission by arbitration) ............................... 127

9.2.4 1.CTC_10.4 – Operating voltage range ............................................................................................. 129

9.3 CTP – Wake-up pulse ............................................................................................................................. 131

9.3.1 General ........................................................................................................................................................ 131

9.3.2 1.CTC_11.1 – Wake-up pulse reception, IUT as master node ................................................... 131

9.3.3 1.CTC_11.2 – Wake-up by clock detection ...................................................................................... 133

9.3.4 1.CTC_11.3 – Wake-up pulse transmission .................................................................................... 134

9.4 CTP – Voltage and duty cycle thresholds ........................................................................................ 135

9.4.1 General ........................................................................................................................................................ 135

9.4.2 1.CTC_12.1 – Voltage threshold test 1 .............................................................................................. 135

9.4.3 1.CTC_12.2 – Voltage threshold test 2 .............................................................................................. 138

9.4.4 1.CTC_12.3 – Duty cycle threshold test ............................................................................................ 139

9.5 CTP – Network state current characteristics ................................................................................ 142

9.5.1 1.CTC_13.1 – Drive current test .......................................................................................................... 142

9.5.2 1.CTC_13.2 – Input leakage test .......................................................................................................... 144

9.5.3 1.CTC_13.3 – Reverse leakage current test .................................................................................... 146

9.6 CTP – Physical signal slope control................................................................................................... 148

9.6.1 1.CTC_14.1 – Duty cycle measurement 1 ......................................................................................... 148

9.6.2 1.CTC_14.2 – Duty cycle measurement 2 ......................................................................................... 151

9.7 CTP – GND / V shift test .................................................................................................................... 152

BAT

9.7.1 GND / V shift test set-up .................................................................................................................. 152

BAT

9.7.2 1.CTC_15.1 – GND shift test .................................................................................................................. 154

9.7.3 1.CTC_15.2 – V shift test ................................................................................................................... 155

BAT

9.8 CTP – Loss of power supply ................................................................................................................. 156

9.8.1 General ........................................................................................................................................................ 156

9.8.2 Loss of battery (V ) and GND test set-up ..................................................................................... 156

BAT

9.8.3 1.CTC_16.1 – Loss of battery test (V ) ........................................................................................... 157

BAT

9.8.4 1.CTC_16.2 – Loss of GND test .............................................................................................................. 158

9.9 CTP – Internal static capacity.............................................................................................................. 160

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9.9.1 Internal static capacity test set-up .................................................................................................... 160

9.9.2 1.CTC_17.1 Internal static capacity ................................................................................................... 160

9.10 CTP – Internal resistance measurement during operation ...................................................... 163

9.10.1 Internal resistor measurment test set-up ...................................................................................... 163

9.10.2 1.CTC_18.1– Internal resistor measurement 1 ............................................................................. 165

9.10.3 1.CTC_18.2– Internal resistor measurement 2 ............................................................................. 166

Bibliography ............................................................................................................................................................... 167

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ISO/DIS 20794-7:2019(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national

standards bodies (ISO member bodies). The work of preparing International Standards is normally

carried out through ISO technical committees. Each member body interested in a subject for which a

technical committee has been established has the right to be represented on that committee.

International organizations, governmental and non-governmental, in liaison with ISO, also take part in

the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all

matters of electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www.iso.org/patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see

www.iso.org/iso/foreword.html.

This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 31,

Data communication.
A list of all parts in the ISO 20794 series can be found on the ISO website.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www.iso.org/members.html.
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ISO/DIS 20794-7:2019(E)
Introduction

ISO 20794 (all parts) specifies the application (partly), application layer, transport layer, network layer, data link

layer, and physical layer requirements of an in-vehicle network called "clock extension peripheral interface

(CXPI)".

CXPI is an automotive low-speed single-wire network. It is an enabler for reducing vehicle weight and fuel

consumption by reducing wire counts to simple devices like switches and sensors.

CXPI serves as and is designed for automotive control applications for example, door control group, light switch,

and HVAC (Heating Ventilation and Air Conditioning) systems.

The CXPI services, protocols, and their key characteristics are specified in different parts according to the OSI

layers.
— Application and application layer

— application measurement and control data communication to exchange information between

applications in different nodes based on message communication;
— wake-up and sleep functionality;

— two kinds of communication methods can be selected at system design by each node:

i) the event-triggered method, which supports application measurement- and control-based (event-

driven) slave node communication, and

ii) the polling method, which supports slave node communication based on a periodic master schedule;

— performs error detection and reports the result to the application;
— application error management;
— Transport layer and network layer
— transforms a message into a single packet;

— adds protocol control information for diagnostic and node configuration into each packet;

— adds packet identifier for diagnostic and node configuration into each packet;
— performs error detection and reports the result to higher OSI layers.
— Data link layer and physical layer
— provides long and short data frames;
— adds a frame identifier into the frame;
— adds frame information into the frame;
— adds a cyclic redundancy check into the frame;

— performs byte-wise arbitration and reports the arbitration result to higher OSI layers;

— performs frame type detection in reception function;
— performs error detection and reports the result to higher OSI layers.
— performs Carrier Sense Multiple Access (CSMA);
— performs Collision Resolution (CR);

— generates a clock, which is transmitted with each bit to synchronise the connected nodes on the CXPI

network;
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ISO/DIS 20794-7:2019(E)
— supports bit rates up to 20 kbit/s;

To achieve this, it is based on the Open Systems Interconnection (OSI) Basic Reference Model specified in

[1]
ISO/IEC 7498-1 and ISO/IEC 10731 , which str
...

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