ISO 20794-7:2020

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
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STANDARD UNTIL PUBLISHED AS SUCH.
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BEING ACCEPTABLE FOR INDUSTRIAL,
This document is circulated as received from the committee secretariat.
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WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 20794-7:2019(E)
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TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
©
PROVIDE SUPPORTING DOCUMENTATION. ISO 2019

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ISO/DIS 20794-7:2019(E)

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© ISO 2019
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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
2
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
2
7.3.8 2.CTC_2.8 – Given CRC of frame with L_FI_DLC ≠ 1111 . 34
2
7.3.9 2.CTC_2.9 – Given CRC of frame with L_FI_DLC = 1111 / L_FI_DLCext ≥ 0 . 35
2
7.3.10 2.CTC_2.10 – Frame transmission completion . 36
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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
2
7.5.6 2.CTC_4.6 – Data length error with L_FI_DLC = 1111 / L_FI_DLCext ≥ 0 . 50
2
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 =
2
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
2
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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ISO/DIS 20794-7:2019(E)
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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ISO/DIS 20794-7:2019(E)
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
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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
...