Road vehicles -- Clock extension peripheral interface (CXPI)

This document specifies the conformance test plan for ISO 20794-2:2020 implementations. It specifies conformance test cases related to: — concept of operation; — network management; — transfer management; and — error management.

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

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Status
Published
Publication Date
29-Oct-2020
Current Stage
5060 - Close of voting Proof returned by Secretariat
Start Date
25-Sep-2020
Completion Date
25-Sep-2020
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INTERNATIONAL ISO
STANDARD 20794-5
First edition
2020-10
Road vehicles — Clock extension
peripheral interface (CXPI) —
Part 5:
Application layer conformance test
plan
Véhicules routiers — Interface périphérique d’extension d'horloge
(CXPI) —
Partie 5: Plan de test de conformité de la couche application
Reference number
ISO 20794-5:2020(E)
ISO 2020
---------------------- Page: 1 ----------------------
ISO 20794-5:2020(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 20794-5:2020(E)
Contents Page

Foreword ..........................................................................................................................................................................................................................................v

Introduction ................................................................................................................................................................................................................................vi

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

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

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

4 Symbols and abbreviated terms ........................................................................................................................................................... 3

4.1 Symbols ......................................................................................................................................................................................................... 3

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

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

6 General test specification considerations .................................................................................................................................. 4

6.1 General ........................................................................................................................................................................................................... 4

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 User_Specific configurations.................................................................................................................................. 8

6.6.4 W/S_Init configurations .................. ......................................................................................................................... .. 8

6.6.5 W/S_Passive configurations ................................................................................................................................... 8

6.6.6 W/S_RdySleep configurations .............................................................................................................................. 8

6.6.7 W/S_NotRdySleep configurations ..................................................................................................................... 8

6.6.8 A_WSSup configurations ........................................................................................................................................... 9

6.6.9 NonW/S configurations ............................................................................................................................................. 9

6.6.10 ErrDet configurations .................................................................................................................................................. 9

6.6.11 Event configurations ........................................................................................................................................... .......... 9

6.6.12 Polling configurations ................................................................................................................................................. 9

6.7 SUT initialisation ................................................................................................................................................................................10

6.7.1 General...................................................................................................................................................................................10

6.7.2 Default initialisation ..................................................................................................................................................10

6.7.3 Sleep initialisation .......................................................................................................................................................10

6.7.4 Power-off initialisation ............................................................................................................................................10

6.7.5 Transmission prohibition initialisation ....................................................................................................10

6.7.6 Clock supply of secondary clock master initialisation .................................................................10

7 Application conformance test plan ................................................................................................................................................10

7.1 General ........................................................................................................................................................................................................10

7.2 Network management ...................................................................................................................................................................10

7.2.1 General...................................................................................................................................................................................10

7.2.2 State transition definition .....................................................................................................................................11

7.2.3 State transition CTCs .................................................................................................................................................11

7.2.4 Wake-up request/notification of master node trigger CTCs...................................................15

7.2.5 Wake-up request/notification of slave node trigger CTCs........................................................18

7.2.6 Sleep request/notification CTCs ......................................................................................................................25

7.2.7 Network Management multi clock master processing CTCs ..................................................31

7.3 Fault management ............................................................................................................................................................................34

7.3.1 Error detection/recovery CTCs ........................................................................................................................34

7.3.2 CXPI network error CTCs .......................................................................................................................................41

7.3.3 SCT error CTCs ................................................................................................................................................................42

7.3.4 Error notification between CXPI nodes CTCs ......................................................................................43

8 Application layer conformance test plan .................................................................................................................................45

© ISO 2020 – All rights reserved iii
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ISO 20794-5:2020(E)

8.1 General ........................................................................................................................................................................................................45

8.2 Transfer management CTCs ......................................................................................................................................................45

8.2.1 General...................................................................................................................................................................................45

8.2.2 7.CTC_10.1 – Master node event-triggered method .......................................................................45

8.2.3 7.CTC_10.2 – Slave node event-triggered method ............................................................................46

8.2.4 7.CTC_10.3 – Master node polling method .............................................................................................46

8.2.5 7.CTC_10.4 – Slave node polling method .................................................................................................47

8.2.6 7.CTC_10.5 – Behaviour of unknown or invalid ReqId reception .......................................48

8.2.7 7.CTC_10.6 – Master node sets unused bits in response message .....................................48

8.2.8 7.CTC_10.7 – Slave node sets unused bits in response message .........................................49

Bibliography .............................................................................................................................................................................................................................51

iv © ISO 2020 – All rights reserved
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ISO 20794-5:2020(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.
© ISO 2020 – All rights reserved v
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ISO 20794-5:2020(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 Condition) 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);
vi © ISO 2020 – All rights reserved
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ISO 20794-5:2020(E)

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

CXPI network;
— supports bit rates up to 20 kbit/s.

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

[2]

in ISO/IEC 7498-1 and ISO/IEC 10731 , which structures communication systems into seven layers.

Figure 1 illustrates an overview of communication frameworks beyond the scope of this document

including related standards:

— vehicle normal communication framework, which is composed of ISO 20794-2 and this document;

[3] [4]

— vehicle diagnostic communication framework, which is composed of ISO 14229-1 , ISO 14229-2

[5]
and ISO 14229-8 ;
[10]

— presentation layer standards, e.g. vehicle manufacturer specific or ISO 22901-1 ODX ;

[6] [7] [8]

— lower OSI layers framework, which is composed of ISO 20794-3 , ISO 20794-4 , ISO 20794-6

[9]
and ISO 20794-7 .
[5]

ISO 20794 (all parts) and ISO 14229-8 are based on the conventions specified in the OSI Service

[2]

Conventions (ISO/IEC 10731 ) as they apply for all layers and the diagnostic services.

Figure 1 — ISO 20794 documents reference according to OSI model
© ISO 2020 – All rights reserved vii
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INTERNATIONAL STANDARD ISO 20794-5:2020(E)
Road vehicles — Clock extension peripheral interface
(CXPI) —
Part 5:
Application layer conformance test plan
1 Scope

This document specifies the conformance test plan for ISO 20794-2:2020 implementations.

It specifies conformance test cases related to:
— concept of operation;
— network management;
— transfer management; and
— error management.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

ISO/IEC 7498-1, Information processing systems — Open systems interconnection — Basic reference model

ISO 20794-2:2020, Road vehicles — Clock extension peripheral interface (CXPI) — Part 2: Application layer

3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 20794-2, ISO/IEC 7498-1 and

the following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
clock master
node that transmits clock (3.4) to the lower OSI layers (3.2)
3.2
lower OSI layer
OSI layer lower than application layer
3.3
master node

node that provides the schedule (3.10) master management (include ReqTypeId transmission), the

primary clock (3.7) and optionally the sleep message transmission management
© ISO 2020 – All rights reserved 1
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ISO 20794-5:2020(E)
3.4
clock
function that synchronises all nodes on the CXPI network
3.5
initiator
node that transmits messages
3.6
passive
node that receives messages
3.7
primary clock
clock (3.4) that is provided by the master node (3.3)
3.8
REPEAT
pseudo code command for an iteration
3.9
REPEAT END
pseudo code command for ending an iteration
3.10
schedule
origin of periodic frame transmission
3.11
secondary clock
clock (3.4) that is provided by one dedicated slave node (3.13)
3.12
sequence
transmission and reception procedure of messages among two or more nodes
3.13
slave node
node other than master node (3.3) connected to the CXPI network
3.14
slave initiator node
node that is woken up by its own slave node (3.13)
3.15
slave passive node
node that is woken up by another slave node (3.13)
3.16
wake-up pulse
stimulus initiated by a node used for wake-up of other nodes on the CXPI network
2 © ISO 2020 – All rights reserved
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ISO 20794-5:2020(E)
4 Symbols and abbreviated terms
4.1 Symbols
--- empty cell/undefined
kbit/s kilobit per second
t master node clock start time
clock_start_m
t master node clock stop time
clock_stop_m
t slave node sleep state transi-
sleep_s
tion time
t master node wake-up time
wakeup_m
t slave node wake-up recovery time
wakeup_recovery_s
t slave node wake-up time
wakeup_s
t master node wake-up schedule
wakeup_schedule_m
time
4.2 Abbreviated terms
ASP abstract service primitive
AL application layer
APP application
CRC cyclic redundancy check
DLC data length code
ECU electronic control unit
EMI electro-magnetic interference
ErrDet error detection
ETS enhanced testability service
IUT implementation under test
OSI open systems interconnection
PDU protocol data unit
PID protected identifier
PCO point of control and observation
ReqId request identifier
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ISO 20794-5:2020(E)
ReqTypeId request type identifier
SCT sequence count
SUT system under test
5 Conventions
[2] [1]

This document is based on OSI service conventions as specified in ISO/IEC 10731 and ISO/IEC 9646-1

for conformance test system setup.
6 General test specification considerations
6.1 General

This document covers the conformance test cases (CTC) to verify the requirements described in

ISO 20794-2 application layer document.
6.2 Test conditions

Tests can be performed at room temperature, if the temperature is in the range of 15° C to 35° C. Also,

the tests shall be performed under room EMI (electro-magnetic interference) conditions.

6.3 IUT requirements

The occurrence of the error specified in ISO 20794-2:2020, 9.6.8 shall be notified to the application.

The IUT shall be initialised in the test case respectively.
6.4 CTC definition

The definition of each test case specifies, whether the IUT is a master or slave node. Each CTC is defined

in the structure as defined in Table 1.
Table 1 — CTC definition example
Item Content
CTC # – Title [OSI layer #].CTC_[number_name]
E.g. 8.CTC_1.4 – State machine – Slave node – Sleep permission
Purpose This CTC shall verify …

E.g. This CTC verifies the test for the slave node to transit into the sleep state with sleep per-

mission. This CTC is applicable only to an IUT, which supports the wake-up/sleep feature.

Reference REQ document, REQ number – REQ name
E.g. ISO 20794-2:2020, REQ 8.3 APP – NM – Normal, standby, and sleep states;
Prerequisite The test system set-up shall be in accordance with Figure 2.
The clock master is implemented in the LT of the test system.
Set-up — The IUT shall be configured as a slave node.

— The IUT shall be configured to default (see 6.6) and in addition support W/S_RdySleep

configurations (see 6.6.6).
— The bit rate shall be set to the default value (see 6.6).
— The SUT shall be initialised to the sleep state (see 6.7.3).
4 © ISO 2020 – All rights reserved
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ISO 20794-5:2020(E)
Table 1 (continued)
Item Content

Step 1. A short description of the test step e.g. LT shall transmit the wake-up pulse.

2. A short description of the test step e.g. LT shall observe any messages on the CXPI

network and shall report to the UT.
Iteration Definition of repetitions of test procedure steps.
Example:
REPEAT step 1 to step 2, 5 times;
…;
REPEAT END.

Expected Define the expected behaviour of IUT by checking on the CXPI network when the test step is

response executed. Example:
After step 1: the IUT shall receive a wake-up notification pulse, waits t time
cxpi_network_error
from the wake-up pulse.
After step 2: the LT shall report the observation on the CXPI network to the UT.

Remark E.g. either "---" if no remark or "Observation of t time and t time starts

wakeup_schedule_m wakeup_m
from second rising edge of clock."
6.5 Test system set-up

The test system set-up follows ISO/IEC 9646-1 and consists of a test system and a system under test

(SUT) connected via the physical medium. The test system implements an upper tester (UT) and a lower

tester (LT). The test system uses set-up parameters (see Figure 2, key 1) for testing the communication

with the IUT.
The UT uses the test control protocol (see Figure 2, key 2) to control the LT.

The point of control and observation (PCO) functionality between the UT of the test system and the UT

App test stub in the SUT is provided by direct logical access to the abstract service primitive interface

[ASPs (ETSs), PCO, see dashed line in Figure 2, key 3] and the associated parameters of the OSI layer as

specified in the ISO 20794 series.

The UT App test stub in the SUT (see Figure 2, key 4) supports an equivalent part of the ASP (see

Figure 2, key 3) and the associated parameters to control and measure the state(s) of the IUT.

The UT App in the test system, which represents the conformance test controller, manipulates the

service primitive interface parameters in the IUT App test stub via the ASPs (ETSs) and PCO of the OSI

layers to fulfil the purpose of each CTC.

If the IUT is a master node then the LT functions as a slave node. If the IUT is a slave node then the LT

functions as a master node. The test system ensures the precision of the bit time and bit synchronisation

of the master node as specified in ISO 20794-4:2020, 9.3.7.
© ISO 2020 – All rights reserved 5
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ISO 20794-5:2020(E)
Key
1 set-up parameters (CXPI node's electronic data sheet)
2 test control protocol

3 abstract service primitives (ASPs) based on enhanced testability services (ETS) and points of control and

observation (PCO)
4 upper tester application test stub
Figure 2 — Test system set-up
6.6 Configuration of test system and IUT
6.6.1 General

The test system requires set-up parameters (see Figure 2 key 1), which specify OSI layer properties

of the IUT. The IUT-specific data sheet (see Figure 2 key 1) includes set-up parameters, which the test

system requires for the conformance test cases.
Table 2 defines the configurations of the test system and the IUT.
6 © ISO 2020 – All rights reserved
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ISO 20794-5:2020(E)
Table 2 — Configuration of test system and IUT
Configuration item Configuration of test system and IUT
W/S W/S W/S W/S _ A_WSSup Non ErrDet Event Polling
_Init _passive _Rdy Not Rdy W/S
Sleep Sleep
Internal condition of 1 0 1 1 --- --- --- --- ---
2 2 2 2
wake-up
Transmission method --- --- --- --- --- --- --- event polling
Wake-up/sleep 1 1 1 1 0 --- --- --- ---
2 2 2 2 2
TST_FRM_05_REQ_ --- --- --- --- supported --- supported --- ---
PID_ERRBIT by IUT by IUT
Condition of sleep per- 1 1 1 0 --- 0 0 --- ---
2 2 2 2 2 2
mission (sleep_ind)

Table 3 specifies test message names which are used by the IUT and the test system in the CTCs. In each

CTC description, the message setting is specified in the 'Definition' column. If there is no reference to

Table 3, the settings are specified in the CTC.
Table 3 — Configuration of test messages used by IUT and test system
Name Definition

TST_MSG_00_REQ_PTYPE Test message 00 of master node including a ReqTypeId value (00 ) of

16 16
A_ReqId.

TST_MSG_01_REQ_PID Test message 01 of master or slave node including an A_PID value (01

16 16
to 7F ,) of A_ReqId.

TST_MSG_02_REQ_PID_SLEEP Test message 02 for master node including an A_PID value (1F ) of A_ReqId

16 16
for diagnostic and node configuration requests or sleep message.

TST_MSG_03_REQ_PID_UNKNOWN Test message 03 for master or slave node including a not defined A_PID

value of A_ReqId (not defined for reception/transmission by IUT).

TST_MSG_04_REQ_PID_INVALID Test message 04 for master or slave node including an A_PID value of

A_ReqId (not defined for reception/transmission by IUT with an incorrect
parity bit) determined by A_Length = 01 .

TST_MSG_05_REQ_PID_ERRBIT Test message 05 of master or slave node including an error bit A_PID value

(01 to 7F ) of L_ReqId.
16 16
The value of this PID can use a supplier-specific ReqId.

TST_MSG_10_RESP_0-12 Test message 10 for master or slave node including FI field, DATA field and

CRC field determined by 00 ≤ A_Lenght ≤ 0C .
16 16

TST_MSG_11_RESP_12 Test message 11 for master or slave node including FI field, DATA field and

CRC field determined by A_Length = 0C .

TST_MSG_14_RESP_LONG_0-255 Test message 14 of master or slave node including FI field, DATA field and

CRC field determined by 00 ≤ A_Length ≤ FF .
16 16

TST_MSG_17_RESP_SLEEP_8 Test message 17 of master node including FI field, fixed byte pattern of

DATA field and CRC field fixed byte pattern is (00 , FF , FF , FF , FF ,
16 16 16 16 16
FF , FF , FF ) determined by A_Length = 08 .
16 16 16 16
TST_MSG_18_RESP_ERRBIT_0-12 Test
...

DRAFT INTERNATIONAL STANDARD
ISO/DIS 20794-5
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 5:
Application layer conformance test plan
Véhicules routiers — Interface périphérique d’extension d'horloge (CXPI) —
Partie 5: Plan de test de conformité de la couche application
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 20794-5:2019(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 20794-5:2019(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 20794-5:2019(E)
Contents Page

30 1 Scope ....................................................................................................................................................................1

31 2 Normative references ....................................................................................................................................1

32 3 Terms and definitions ....................................................................................................................................2

33 4 Symbols and abbreviated terms .................................................................................................................4

34 4.1 Symbols .................................................................................................................................................................. 4

35 4.2 Abbreviated terms ............................................................................................................................................. 4

36 5 Conventions .......................................................................................................................................................5

37 6 General test specification considerations ..............................................................................................6

38 6.1 General ................................................................................................................................................................... 6

39 6.2 Test conditions .................................................................................................................................................... 6

40 6.3 IUT requirements ............................................................................................................................................... 6

41 6.4 CTC definition ...................................................................................................................................................... 6

42 6.5 Test system set-up ............................................................................................................................................. 7

43 6.6 Configuration of test system and IUT ........................................................................................................ 7

44 6.7 SUT initialisation ............................................................................................................................................. 11

45 7 Application conformance test plan ........................................................................................................ 12

46 7.1 General ................................................................................................................................................................ 12

47 7.2 Network management .................................................................................................................................. 12

48 7.2.1 General ......................................................................................................................... 12

49 7.2.2 State transition definition ............................................................................................ 12

50 7.2.3 State transition CTCs .................................................................................................... 13

51 7.2.4 Wake-up request/notification of master node trigger CTCs ....................................... 19

52 7.2.5 Wake-up request/notification of slave node trigger CTCs .......................................... 25

53 7.2.6 Sleep request/notification CTCs .................................................................................. 34

54 7.2.7 Network Management multi clock master processing CTCs ....................................... 45

55 7.3 Fault management .......................................................................................................................................... 50

56 7.3.1 Error detection/recovery CTCs .................................................................................... 50

57 7.3.2 CXPI network error CTCs .............................................................................................. 64

58 7.3.3 SCT error CTCs .............................................................................................................. 67

59 7.3.4 Error notification between CXPI nodes CTCs ............................................................... 69

60 8 Application layer conformance test plan ............................................................................................. 70

61 8.1 General ................................................................................................................................................................ 70

62 8.2 Transfer management CTCs ....................................................................................................................... 70

63 8.2.1 General ......................................................................................................................... 70

64 8.2.2 7.CTC_10.1 – Event-triggered method ........................................................................ 71

65 8.2.3 7.CTC_10.2 – Event-triggered method ........................................................................ 72

66 8.2.4 7.CTC_10.3 – Polling method ....................................................................................... 73

67 8.2.5 7.CTC_10.4 – Polling method ....................................................................................... 74

68 8.2.6 7.CTC_10.5 – Behaviour of unknown ReqId reception ................................................ 75

69 8.2.7 7.CTC_10.6 – Unused response message .................................................................... 76

70 Bibliography ................................................................................................................................................................. 77

© ISO 2019 – All rights reserved
iii
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ISO/DIS 20794-5:2019(E)
© ISO 2019 – All rights reserved
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ISO/DIS 20794-5:2019(E)
73 Foreword

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

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

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

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

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

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

80 electrotechnical standardization.

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

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

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

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

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

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

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

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

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

90 constitute an endorsement.

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

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

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

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

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

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

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

99 complete listing of these bodies can be found at www.iso.org/members.html.
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Introduction

100 This document set specifies the use cases, the application layer, transport and network layer, data link

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

102 (CXPI)".

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

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

105 CXPI serves as and is designed for automotive control applications, e.g. door control group, light switch

106 and HVAC (Heating Ventilation and Air Condition) systems.

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

108 OSI layers.
109 ⎯ Application layer

110 ⎯ application measurement and control data communication to exchange information between

111 applications in different nodes based on a deterministic schedule table-based message

112 communication;

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

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

115 (event-driven) slave node communication; and

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

117 schedule;

118 ⎯ error management, that provides error detection and reporting to the application.

119 ⎯ Transport and network layer
120 ⎯ transforms a message into a single packet;

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

122 ⎯ adds packet identifier for diagnostic and node configuration into each packet;

123 ⎯ performs transport protocol error detection.
124 ⎯ Data link layer
125 ⎯ provides long and short data frames;
126 ⎯ adds a frame identifier into the frame;
127 ⎯ adds frame information into the frame;
128 ⎯ adds a cyclic redundancy check into the frame;
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129 ⎯ performs byte-wise arbitration and reports the arbitration result to higher OSI layers;

130 ⎯ performs frame type detection in reception function;

131 ⎯ performs data link error detection and reports the result to higher OSI layers.

132 ⎯ Physical layer
133 ⎯ performs Carrier Sense Multiple Access (CSMA);
134 ⎯ performs Collision Resolution (CR);

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

136 CXPI network;
137 ⎯ supports bit rates up to 20 kbit/s.
138

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

140 ISO/IEC 7498-1 0 and ISO/IEC 10731, which structures communication systems into seven layers.

141 Figure 1 illustrates an overview of communication frameworks beyond the scope of this document

142 including related standards:

143 ⎯ vehicle normal communication framework, which is composed of ISO 20794-2 and ISO 20794-5;

144 ⎯ vehicle diagnostic communication framework, which is composed of ISO 14229-1, ISO 14229-2 [1],

145 and ISO 14229-8 [2];

146 ⎯ presentation layer standards, e.g., vehicle manufacturer specific or ISO 22901 ODX [3];

147 ⎯ Lower OSI layers framework, which is composed of ISO 20794-3, ISO 20794-4, ISO 20794-6, and

148 ISO 20794-7 conformance testing.

149 ISO 20794 (all parts) and ISO 14229-8 [2] are based on the conventions specified in the OSI Service

150 Conventions (ISO/IEC 10731) as they apply for all layers and the diagnostic services.

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151
152 Figure 1 — ISO 20794 documents reference according to OSI model
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DRAFT INTERNATIONAL STANDARD ISO/DIS 20794-5:2019(E)
153 Road vehicles — Clock extension peripheral interface
154 (CXPI) — Part 5: Application layer conformance test plan
155 1 Scope

156 This document shall provide all necessary technical information to ensure that test results will be

157 identical even on different test systems, provided that the particular test suite and the test system are

158 compliant to the content of this document.

159 The application layer conformance test plan contains the following descriptions:

160 ⎯ concept of operation conformance test plan;
161 ⎯ network management conformance test plan;
162 ⎯ transfer management conformance test plan; and
163 ⎯ error management conformance test plan.
164 2 Normative references

165 The following referenced documents are indispensable for the application of this document. For dated

166 references, only the edition cited applies. For undated references, the latest edition of the referenced

167 document (including any amendments) applies.

168 ISO 7498-1:1994 (Ed. 1), Information processing systems — Open systems interconnection — Basic

169 reference model

170 ISO/IEC 10731:1994, Information technology — Open Systems Interconnection — Basic Reference

171 Model — Conventions for the definition of OSI services

172 ISO 20794-2, Road vehicles – Clock extension peripheral interface (CXPI) — Part 2: Application layer

173 ISO 14229-1, Road vehicles — unified diagnostic services (UDS) — Part 1: Application layer

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174 3 Terms and definitions

175 For the purposes of this document, the terms and definitions given in ISO 20794-2, ISO/IEC 7498-1, and

176 the following apply.

177 ISO and IEC maintain terminological databases for use in standardization at the following addresses:

178 ⎯ IEC Electropedia: available at http://www.electropedia.org/
179 ⎯ ISO Online browsing platform: available at http://www.iso.org/obp
180 3.1
181 clock master
182 node that transmits clock to the lower OSI layers
183 3.2
184 lower OSI layers
185 OSI layers lower than application layer
186 3.3
187 master node

188 node that provides the schedule master management (include ReqTypeId transmission), the primary

189 clock, and optionally the sleep message transmission management
190 3.4
191 clock
192 function that synchronises all nodes on the CXPI network
193 3.5
194 initiator
195 node that transmit messages
196 3.6
197 passive
198 node that receive messages
199 3.7
200 primary clock
201 clock that is provided by the master node
202 3.8
203 schedule
204 origin of periodic frame transmission
205 3.9
206 secondary clock
207 clock that is provided by one dedicated slave node
208 3.10
209 sequence
210 transmission and reception procedure of messages among two or more nodes
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211 3.11
212 slave node
213 node other than master node connected to the CXPI network
214 3.12
215 slave initiator node
216 node that wakes up from the slave node itself
217 3.13
218 slave passive node
219 node that is wake-up from another slave node
220 3.14
221 wake-up pulse

222 stimulus initiated by a node used for wake-up of other nodes on the CXPI network

223
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224 4 Symbols and abbreviated terms
225 4.1 Symbols
226 kbit/s kilobit per second

227 T time that the master node transmits the clock on the CXPI network at the latest

clock_start_m

228 T time that the master node stops to transmit the clock after master node receives the

clock_stop_m
229 sleep message

230 T time that each slave node transits to sleep state after the node receives the sleep

sleep_s
231 message

232 T minimum time that master node starts the transmission of any Request field (ReqId)

wakeup_m
233 or Request field (ReqTypeId) first for the wakeup sequence

234 T time that slave node starts the transmission of the second wakeup pulse after transmits

wakeup_recovery_s
235 the first wakeup pulse
236 T maximum time until the slave node wakes up by the wakeup sequence
wakeup_s

237 T maximum time until master node starts the transmission of any Request field (ReqId)

wakeup_schedule_m
238 or Request field (ReqTypeId) first for the wakeup sequence
239 4.2 Abbreviated terms
240 AL application layer
241 APP application
242 CRC cyclic redundancy check
243 DID diagnostic data identifier
244 DLC data length code
245 ECU electronic control unit
246 EMI electro-magnetic interference
247 IUT Implementation under test
248 OSI open systems interconnection
249 PDU protocol data unit
250 PID protected identifier
251 ReqId request identifier
252 ReqTypeId request type identifier
253 SCT sequence count
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254 SUT system under test
255 5 Conventions

256 This document is based on the conventions discussed in the OSI Service Conventions as specified in ISO/IEC 10731.

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257 6 General test specification considerations
258 6.1 General

259 This document covers the conformance test cases (CTC) to verify the requirements described in ISO

260 20794-2 application layer document. This CTC specification is not able to cover all contingencies. Due to

261 the fact of the missing vehicle environment, it is possible that the IUT's behavior differs.

262 6.2 Test conditions

263 Tests can be performed at room temperature in a range of 15 to 35 degrees of Celsius. Also, the tests shall

264 be performed under room EMI (electro-magnetic interference) conditions.
265 6.3 IUT requirements

266 The occurrence of the error specified in ISO 20794-2:9.6.6 "APP – Error notification on CXPI network

267 (optional)" shall be notified to higher OSI layers.
268 IUT shall be initialised in the test case respectively.
269 6.4 CTC definition

270 The definition of each test case specifies, whether the IUT is a master or slave node. each CTC is defined

271 in the structure as defined in Table 1.
272 Table 1 — CTC definition
Item Content
CTC # – Title [OSI layer #].CTC_[number_name]
Purpose To verify that the … e.g.
Reference REQ document, REQ number – REQ name
Prerequisite e.g., tested node in s_NetInterface_Normal_Operation
Set-up 1. IUT as master node or slave node;

2. Configuration: Define setup or using the test frame for the IUT and the test system;

3. Bit rate: Define the bit rate for each test case;

4. SUT initialisation: Define an initialisation of the IUT state before each test case;

Step 1 A short description of the test case.
Iteration Definition of repetitions of test procedure steps:

Expected Define the expected behaviour of IUT by checking on CXPI network when the test Step is

response executed.
Remark ---
273
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274 6.5 Test system set-up

275 The test system ensures the precision of the bit time and bit synchronisation of the master node as

276 specified in ISO 20794-2. If the IUT is a master node then the LT functions as a slave node and vice versa.

277 The UT is implemented in the DUT and contains the conformance test controller. The conformance test

278 controller in the UT interfaces with the UT service interface of the IUT and LT. The control and

279 measurement functionality is provided by direct access to the service interface (key 3) and the associated

280 parameters of the OSI layer as specified in ISO 20794-2.

281 The conformance test controller manipulates the service interface parameters of the OSI layers to fulfil

282 the purpose of each conformance test case (CTC). Figure 2 shows the test system set-up.

283 IUT generates requests to lower OSI layers and receives notification from lower OSI layers.

284
285
Key
1 IUT-specific set-up parameters (CXPI node's electronic data sheet)
2 Test control protocol
3 Points of control and observation and abstract service primitives
4 OSI layers 7 to 5 protocol data units
286 Figure 2 — Test system set-up
287
288 6.6 Configuration of test system and IUT

289 The test system requires set-up parameters (see Figure 2 key 1), which specify OSI-7 to 5 layer properties

290 of the IUT. The IUT-specific data sheet (key 1) includes set-up parameters which the test system requires

291 to perform conformance test cases.
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292 The IUT-specific data sheet includes at least the following information:

293 ⎯ The request identifier uses 01 to 7F and uses 00 in the request protected type identifier field;

16 16 16

294 ⎯ The request identifier that transmits a message containing an error bit may use 3F

295 ⎯ Internal condition of wake-up uses initial wake-up trigger also set bit value 0 or 1 as wakeup_ind

296 ⎯ Transmission method set either Event-triggered method or Polling method
297 ⎯ Condition of sleep permission uses bit value 0 or 1 as sleep_ind
298 ⎯ Bit rate (default 20 kbit/s if not otherwise specified)
299
300 User Specific configuration;
301 ⎯ Internal condition of wake-up: DC
302 ⎯ Transmission method: DC
303 ⎯ Wake-up/sleep: DC
304 ⎯ Condition of sleep permission (sleep_ind): DC
305 W/S_Init configuration;
306 ⎯ Internal condition of wake-up: YES
307 ⎯ Transmission method: DC
308 ⎯ Wake-up/sleep: YES
309 ⎯ Condition of sleep permission (sleep_ind): 1
310 W/S_Passive configuration;
311 ⎯ Internal condition of wake-up: NO
312 ⎯ Transmission method: DC
313 ⎯ Wake-up/sleep: YES
314 ⎯ Condition of sleep permission (sleep_ind): 1
315 W/S_RdySleep configuration;
316 ⎯ Internal condition of wake-up: YES
317 ⎯ Transmission method: DC
318 ⎯ Wake-up/sleep: YES
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319 ⎯ Condition of sleep permission (sleep_ind): 1
320 W/S_NotRdySleep configuration;
321 ⎯ Internal condition of wake-up: YES
322 ⎯ Transmission method: DC
323 ⎯ Wake-up/sleep: YES
324 ⎯ Condition of sleep permission (sleep_ind): 0
325 NonW/S configuration;
326 ⎯ Transmission method: DC
327 ⎯ Wake-up/sleep: NO
328 ⎯ TST_FRM_05_REQ_PID_ERRBIT: USE
329 ⎯ Condition of sleep permission (sleep_ind): DC
330 NonW/S configuration;
331 ⎯ Internal condition of wake-up: NA
332 ⎯ Transmission method: DC
333 ⎯ Wake-up/sleep: NA
334 ⎯ TST_FRM_05_REQ_PID_ERRBIT: USE
335 ⎯ Condition of sleep permission (sleep_ind): 0
336 ErrDet configuration;
337 ⎯ Internal condition of wake-up: DC
338 ⎯ Transmission method: DC
339 ⎯ Wake-up/sleep: DC
340 ⎯ Condition of sleep permission (sleep_ind): 0
341 Event configuration;
342 ⎯ Internal condition of wake-up: DC
343 ⎯ Transmission method: Event
344 ⎯ Wake-up/sleep: DC
345 ⎯ Condition of sleep permission (sleep_ind): DC
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346 Polling configuration;
347 ⎯ Internal condition of wake-up: DC
348 ⎯ Transmission method: Polling
349 ⎯ Wake-up/sleep: DC
350 ⎯ Condition of sleep permission (sleep_ind): DC
351
352 Table 2 — Configuration of test system and IUT
Configuration of test system and IUT
User W/S W/S W/S W/S Non ErrDet Event Polling
Specific _Init _passive _Rdy _Not W/S
Sleep Rdy
Sleep
Internal condition of DC YES NO YES YES NA DC DC DC
wake-up
Transmission method DC DC DC DC DC DC DC Event Polling
Wake-up/sleep DC YES YES YES YES NA DC DC DC
TST_FRM_05_REQ_PID NA NA NA NA NA NA USE NA NA
_ERRBIT
Condition of sleep DC 1 1 1 0 0 0 DC DC
permission (sleep_ind)
353

354 Table 3 specifies test message names which are used by the IUT and the test system in the CTCs. In each

355 CTC description, the message setting is specified in the 'Description' column. The configuration described

356 is a suitable configuration for the each CTC. If there is no reference to the Table 3, the settings are

357 specified in the CTC.
358 Table 3 — Configuration of test messages used by IUT and test system
Test message name Test message definition

TST_MSG_00_REQ_PTYPE Test message 0016 of master node including a ReqTypeId value (0016) of

A_ReqId.

TST_MSG_01_REQ_PID Test message 0116 of master or slave node including an A_PID value (0116

to 7F16,) of A_ReqId.

TST_MSG_02_REQ_PID_SLEEP Test message 0216 for master node including an A_PID value (1F16) of

A_ReqId for diagnostic and node configuration requests or sleep message.

TST_MSG_03_REQ_PID_UNKNOWN Test message 0316 for master or slave node including a not defined A_PID

value of A_ReqId (not defined for reception/transmission by IUT).
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Test message name Test message definition

TST_MSG_04_REQ_PID_INVALID Test message 0416 for master or slave node including an A_PID value of

A_ReqId (not defined for reception/transmission by IUT with an incorrect
parity bit) determined by A_Length = 01 .

TST_MSG_05_REQ_PID_ERRBIT Test message 05 of master or slave node including an error bit A_PID

value (01 to 7F ,) of L_ReqId.
16 16
The value of this PID can use supplier-specific ReqId.

TST_MSG_10_RESP_0-11 Test message 10 for master or slave node including FI field, DATA field

and CRC field determined by 0016 ≤ A_Lenght ≤ 0B16.

TST_MSG_11_RESP_12 Test message 11 for master or slave node including FI field, DATA field

and CRC field determined by A_Length = 0C16.

TST_MSG_14_RESP_LONG_255 Test message 14 of master or slave node including FI field, DATA field

and CRC field determined by A_Length ≤ FF16.

TST_MSG_17_RESP_SLEEP_8 Test message 17 of master node including FI field, fixed byte pattern of

DATA field and CRC field fixed byte pattern is (0016, FF16, FF16, FF16, FF16,
FF16, FF16, FF16,) determined by A_Length = 0816.

TST_MSG_18_RESP_ERRBIT_0-12 Test message 1816 of master node including FI field, DATA field with an

error bit and CRC field determined by 0016 ≤ A_Length ≤ 0C16
359
360 6.7 SUT initialisation
361 An initialisation of the IUT shall be performed before each CTC.
362 Default initialisation;

363 IUT shall be reset so that the transmission/reception A_ReqIds shall be configured and the error counter

364 value is reset (0). If the IUT supports wake-up/sleep, it shall be in sleep prohibition state. If the IUT is a

365 master node, it shall be ready to transmit the request field to the lower OSI layers. If the IUT is a slave

366 node, it shall be ready to transmit response PDUs upon the reception of A_ReqId from the master node.

367 Sleep initialisation;
368 IUT shall support wake-up/sleep functi
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