ISO 11898-2:2016

INTERNATIONAL ISO
STANDARD 11898-2
Second edition
2016-12-15
Road vehicles — Controller area
network (CAN) —
Part 2:
High-speed medium access unit
Véhicules routiers — Gestionnaire de réseau de communication
(CAN) —
Partie 2: Unité d’accès au support à haute vitesse
Reference number
©
ISO 2016
© ISO 2016, Published in Switzerland
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ii © ISO 2016 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols and abbreviated terms . 2
5 Functional description of the HS-PMA . 3
5.1 General . 3
5.2 HS-PMA test circuit . 3
5.3 Transmitter characteristics . 4
5.4 Receiver characteristics . 8
5.5 Receiver input resistance . 9
5.6 Transmitter and receiver timing behaviour . 9
5.7 Maximum ratings of V , V and V .
CAN_H CAN_L Diff 11
5.8 Maximum leakage currents of CAN_H and CAN_L .12
5.9 Wake-up from low-power mode .12
5.9.1 Overview .12
5.9.2 Basic wake-up.13
5.9.3 Wake-up pattern wake-up .13
5.9.4 Selective wake-up . .13
5.10 Bus biasing .18
5.10.1 Overview .18
5.10.2 Normal biasing .18
5.10.3 Automatic voltage biasing .18
6 Conformance .20
Annex A (informative) ECU and network design .21
Annex B (informative) PN physical layer modes .29
Bibliography .30
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 on 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 the following URL: www.iso.org/iso/foreword.html.
The committee responsible for this document is ISO/TC 22, Road vehicles, Subcommittee SC 31, Data
communication.
This second edition cancels and replaces the first edition (ISO 11898-2:2003), which has been
technically revised, with the following changes:
— max output current on CANH/CANL has been defined (Table 4);
— optional TXD timeout has been defined (Table 7);
— receiver input resistance range has been changed (Table 10);
— Bit timing parameters for CAN FD for up to 2 Mbps have been defined (Table 13);
— Bit timing parameters for CAN FD for up to 5 Mbps have been defined (Table 14);
— content of ISO 11898-5 and ISO 11898-6 has been integrated to ensure there is one single ISO
Standard for all HS-PMA implementations;
— selective wake-up (formerly ISO 11898-6) CAN FD tolerance has been defined;
— wake-filter timings (formerly in ISO 11898-5) have been changed (Table 20)
— requirements and assumptions about the PMD sublayer have been shifted to Annex A, to clearly
focus on the HS-PMA implementation.
A list of all parts in the ISO 11898 series can be found on the ISO website.
iv © ISO 2016 – All rights reserved

Introduction
ISO 11898 was first published as one document in 1993. It covered the CAN data link layer as well as
the high-speed physical layer. In the reviewed and restructured ISO 11898 series, ISO 11898-1 and
ISO 11898-4 defined the CAN protocol and time-triggered CAN (TTCAN) while ISO 11898-2 defines the
high-speed physical layer, and ISO 11898-3 defined the low-speed fault tolerant physical layer.
Figure 1 shows the relation of the Open System Interconnection (OSI) layers and its sublayers to
ISO 11898-1, this document as well as ISO 11898-3.
Key
AUI attachment unit interface
MDI media dependant interface
OSI open system interconnection
Figure 1 — Overview of ISO 11898 specification series
The International Organization for Standardization (ISO) draws attention to the fact that it is claimed
that compliance with this document may involve the use of a patent concerning the selective wake-up
function given in 5.9.4.
ISO takes no position concerning the evidence, validity and scope of this patent right.
The holder of this patent right has assured ISO that he/she is willing to negotiate licenses under
reasonable and non-discriminatory terms and conditions with applicants throughout the world. In
this respect, the statement of the holder of this patent right is registered with ISO. Information may be
obtained from the following:
Audi AG Elmos Semiconductor AG Renesas Electronics Europe GmbH
August-Horch-Str. Heinrich-Hertz-Str. 1 Arcadiastr. 10
85045 Ingolstadt 44227 Dortmund 40472 Düsseldorf
Germany Germany Germany
BMW Group Freescale Semiconductor Inc. Robert Bosch GmbH
Knorrstr. 147 6501 W. William Canon Drive PO Box 30 02 20
80788 München Austin, Texas 70442 Stuttgart
Germany United States Germany
Continental Teves AG & Co. oHG General Motors Corp. STMicroelectronics Application
Guerickestr. 7 30001 VanDyke, Bldg 2-10 GmbH
60488 Frankfurt am Main Warren, MI 48090-9020 Bahnhofstrasse 18
Germany United States of America 85609 Aschheim Dornach
Germany
DENSO CORP. NXP BV Volkswagen AG
1-1, Showa-cho, Kariya-shi High Tech Campus 60 PO Box 011/1770
Aichi-ken 448-8661 5656 AG Eindhoven 38436 Wolfsburg
Japan The Netherlands Germany
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights other than those identified above. ISO shall not be held responsible for identifying any
or all such patent rights. ISO (www.iso.org/patents) maintains on-line databases of patents relevant
to their standards. Users are encouraged to consult the databases for the most up to date information
concerning patents.
vi © ISO 2016 – All rights reserved

INTERNATIONAL STANDARD ISO 11898-2:2016(E)
Road vehicles — Controller area network (CAN) —
Part 2:
High-speed medium access unit
1 Scope
This document specifies the high-speed physical media attachment (HS-PMA) of the controller area
network (CAN), a serial communication protocol that supports distributed real-time control and
multiplexing for use within road vehicles. This includes HS-PMAs without and with low-power mode
capability as well as with selective wake-up functionality. The physical media dependant sublayer is
not in the scope of this document.
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 11898-1:2015, Road vehicles — Controller area network (CAN) — Part 1: Data link layer and physical
signalling
ISO 16845-2, Road vehicles — Controller area network (CAN) conformance test plan — Part 2: High-speed
medium access unit with selective wake-up functionality
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 11898-1 and the following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
NOTE See Figure A.1 for a visualization of the definitions.
3.1
attachment unit interface
AUI
interface between the PCS that is specified in ISO 11898-1 and the PMA that is specified in this document
3.2
ground
GND
electrical signal ground
3.3
legacy implementation
HS-PMA implementation that has been released prior to the publication of this document
3.4
low-power mode
mode in which the transceiver is not capable of transmitting or receiving messages, except for the
purposes of determining if a WUP or WUF is being received
3.5
medium attachment unit
MAU
unit that comprises the physical media attachment and the media dependent interface
3.6
media dependent interface
MDI
interface that ensures proper signal transfer between the media and the physical media attachment
3.7
normal-power mode
mode in which the transceiver is fully capable of transmitting and receiving messages
3.8
physical coding sublayer
PCS
sublayer that performs bit encoding/decoding and synchronization
3.9
physical media attachment
PMA
sublayer that converts physical signals into logical signals and vice versa
3.10
transceiver
implementation that comprises one or more physical media attachments
4 Symbols and abbreviated terms
For the purposes of this document, the symbols and abbreviated terms given in ISO 11898-1 and the
following apply. Some of these abbreviations are also defined in ISO 11898-1. If the definition of the
term in this document is different from the definition in ISO 11898-1, this definition applies.
AUI attachment unit interface
DLC data length code
EMC electromagnetic compatibility
ESD electro static discharge
GND ground
HS-PMA high-speed PMA
MAU medium attachment unit
MDI media dependent interface
PCS physical coding sublayer
PMA physical media attachment
2 © ISO 2016 – All rights reserved

PMD physical media dependent
WUF wake-up frame
WUP wake-up pattern
5 Functional description of the HS-PMA
5.1 General
The HS-PMA comprises one transmitter and one receiving entity. It shall be able to bias the connected
physical media, an electric two-wire cable, relative to a common ground. The transmitter entity shall
drive a differential voltage between the CAN_H and CAN_L signals to signal a logical 0 (dominant)
or shall not drive a differential voltage to signal a logical 1 (recessive) to be received by other nodes
connected to the very same media. These two signals are the interface to the physical media dependent
sublayer.
The HS-PMA shall provide an AUI to the physical coding sublayer as specified in ISO 11898-1. It
comprises the TXD and RXD signals as well as the GND signal. The TXD signal receives from the physical
coding sublayer the bit-stream to be transmitted on the MDI. The RXD signal transmits to the physical
coding sublayer the bit-stream received from the MDI.
Implementations that comprise one or more HS-PMAs shall at least support the normal-power mode of
operation. Optionally, a low-power mode may be implemented.
Some of the items specified in the following depend on the operation mode of the (part of the)
implementation, in which the HS-PMA is included.
Table 1 shows the possible combinations of HS-PMA operating modes and expected behaviour.
Table 1 — HS-PMA operating modes and expected behaviour
Operating mode Bus biasing behaviour Transmitter behaviour
a
Normal Bus biasing active Dominant or recessive
Low-power Bus biasing active or inactive Recessive
a
Depends on input conditions as described in this document.
All parameters given in this subclause shall be fulfilled throughout the operating temperature range
and supply voltage range (if not explicitly specified for unpowered) as specified individually for every
HS-PMA implementation.
5.2 HS-PMA test circuit
The outputs of the HS-PMA implementation to the CAN signals are called CAN_H and CAN_L, TXD is
the transmit data input and RXD is the receive data output. Figure 2 shows the external circuit that
defines the measurement conditions for all required voltage and current parameters. R represents
L
the effective resistive load (bus load) for an HS-PMA implementation, when used in a network, and C
represents an optional split-termination capacitor. The values of R and C vary for different parameters
L 1
that the HS-PMA implementation needs to meet and are given as condition in Tables 2 to 20.
Key
V differential voltage between CAN_H and CAN_L wires
Diff
V single ended voltage on CAN_H wire
CAN_H
V single ended voltage on CAN_L wire
CAN_L
C capacitive load on RXD
RXD
Figure 2 — HS-PMA test circuit
5.3 Transmitter characteristics
This subclause specifies the transmitter characteristics of a single HS-PMA implementation under the
conditions as depicted in Figure 2; so no other HS-PMA implementations are connected to the media.
The behaviour of an HS-PMA implementation connected to other HS-PMAs is outside the scope of this
subclause. Refer to A.2 for consideration when multiple HS-PMAs are connected to the same media. The
voltages and currents that are required on the CAN_L and CAN_H signals are specified in Tables 2 to 6.
Table 2 specifies the output characteristics during dominant state.
Figure 3 illustrates the voltage range for the dominant state.
4 © ISO 2016 – All rights reserved

Table 2 — HS-PMA dominant output characteristics
Value
Parameter Notation Condition
Min Nom Max
V V V
Single ended voltage on CAN_H V +2,75 +3,5 +4,5 R = 50 Ω …65 Ω
CAN_H L
Single ended voltage on CAN_L V +0,5 +1,5 +2,25 R = 50 Ω …65 Ω
CAN_L L
Differential voltage on normal bus load V +1,5 +2,0 +3,0 R = 50 Ω …65 Ω
Diff L
Differential voltage on effective resistance Not
a
V +1,5 +5,0 R = 2 240 Ω
Diff L
during arbitration defined
Optional:
V +1,4 +2,0 +3,3 R = 45 Ω …70 Ω
Diff L
Differential voltage on extended bus load
range
a
2 240 Ω is emulating a situation with up to 32 nodes sending dominant simultaneously. In such case, the effective load
resistance for a single node decreases (a node does drive only a part of the nominal bus load). Assuming a MAX R of 70 Ω,
L
this scenario covers a 32 nodes network. (2 240 Ω/70 Ω per node = 32 nodes.)
All requirements in this table apply concurrently. Therefore, not all combinations of V and V are compliant with
CAN_H CAN_L
the defined differential voltage (see Figure 3).
Measurement setup according to Figure 2 (only one HS-PMA present):
R , see “Condition” column above
L
C = 0 pF (not present)
C = 0 pF (not present)
C = 0 pF (not present)
RXD
Key
V differential voltage between CAN_H and CAN_L wires
Diff
V single ended voltage on CAN_H wire
CAN_H
V single ended voltage on CAN_L wire
CAN_L
Figure 3 — Voltage range of V during dominant state of CAN node, when V varies from
CAN_H CAN_L
minimum to maximum voltage level (50 Ω … 65 Ω bus load condition)
In order to achieve a level of RF emission that is acceptably low, the transmitter shall meet the driver
signal symmetry as required in Table 3.
Table 3 — HS-PMA driver symmetry
Value
Parameter Notation
Min Nom Max
a
Driver symmetry v +0,9 +1,0 +1,1
sym
a
v = (V + V )/V , with V being the supply voltage of the transmitter.
sym CAN_H CAN_L CC CC
v shall be observed during dominant and recessive state and also during the transition from dominant to
sym
recessive and vice versa, while TXD is stimulated by a square wave signal with a frequency that corresponds
to the highest bit rate for which the HS-PMA implementation is intended, however, at most 1 MHz (2 Mbit/s)
(HS-PMA in normal mode).
Measurement setup according to Figure 2:
R = 60 Ω (tolerance ≤ ±1 %)
L
C = 4,7 nF (tolerance ≤ ±5 %)
C = 0 pF (not present)
C = 0 pF (not present)
RXD
The maximum output current of the transmitter shall be limited according to Table 4.
Table 4 — Maximum HS-PMA driver output current
Value
Parameter Notation Condition
Min Max
mA mA
Absolute current on CAN_H I not defined 115 −3 V ≤ V ≤ +18 V
CAN_H CAN_H
Absolute current on CAN_L I not defined 115 −3 V ≤ V ≤ +18 V
CAN_L CAN_L
Measurement setup according to Figure 2 with either V or V enforced to voltage levels as mentioned in the
CAN_H CAN_L
conditions by connection to an external voltage source, while the HS-PMA is driving the output dominant. The absolute
maximum value does not care about the direction in which the current flows.
R > 10 Ω (not present)
L
C = 0 pF (not present)
C = 0 pF (not present)
C = 0 pF (not present)
RXD
NOTE  It is expected that the implementation does not stop driving its output dominant when the differential voltage
between CAN_H and CAN_L is outside the limits given in the Condition column. The minimum output current is implicitly
defined in Table 2 and thus can be expected to be above 30 mA.
Table 5 specifies the recessive output characteristics when bus biasing is active.
6 © ISO 2016 – All rights reserved

Table 5 — HS-PMA recessive output characteristics, bus biasing active
Value
Parameter Notation
Min Nom Max
V V V
Single ended output voltage on CAN_H V +2,0 +2,5 +3,0
CAN_H
Single ended output voltage on CAN_L V +2,0 +2,5 +3,0
CAN_L
Differential output voltage V −0,5 0 +0,05
Diff
All requirements in this table apply concurrently. Therefore, not all combinations of V and V are compliant with
CAN_H CAN_L
the defined differential output voltage.
Measurement setup according to Figure 2:
R > 10 Ω (not present)
L
C = 0 pF (not present)
C = 0 pF (not present)
C = 0 pF (not present)
RXD
Table 6 specifies the recessive output characteristics when bus biasing is inactive.
Table 6 — HS-PMA recessive output characteristics, bus biasing inactive
Value
Parameter Notation
Min Nom Max
V V V
Single ended output voltage on CAN_H V −0,1 0 +0,1
CAN_H
Single ended output voltage on CAN_L V −0,1 0 +0,1
CAN_L
Differential output voltage V −0,2 0 +0,2
Diff
See 5.10 to determine when bias shall be inactive.
Measurement setup according to Figure 2:
R > 10 Ω (not present)
L
C = 0 pF (not present)
C = 0 pF (not present)
C = 0 pF (not present)
RXD
The implementation of an HS-PMA may limit the duration of dominant transmission in order not to
prevent other CAN nodes from communication when the TXD input is permanently asserted. The HS-
PMA implementation should implement a timeout within the limits specified in Table 7.
Table 7 — Optional HS-PMA transmit dominant timeout
Value
Parameter Notation
Min Max
ms ms
a
Transmit dominant timeout t 0,8 10,0
dom
a
A minimum value of 0,3 ms is accepted for legacy implementations.
NOTE There is a relation between the t minimum value and the minimum bit rate. A t minimum
dom dom
value of 0,8 ms accommodates 17 consecutive dominant bits at bit rates greater than or equal to 21,6 kbit/s
and 36 consecutive dominant bits at bit rates greater than or equal to 45,8 kbit/s. The value 17 reflects PMA
implementation attempts to send a dominant bit and every time sees a recessive level at the receive data input.
The value 36 reflects six consecutive error frames when there is a bit error in the last bit of the first five attempts.
5.4 Receiver characteristics
The receiver uses the transmitter output signals CAN_H and CAN_L as differential input. Figure 2 shows
the definition of the voltages at the connections of the HS-PMA’s implementation.
When the HS-PMA implementation is in its low-power mode and bus biasing is active, then the recessive
and dominant state differential input voltage ranges according to Table 8 apply.
Table 8 — HS-PMA static receiver input characteristics, bus biasing active
Value
Parameter Notation Condition
Min Max
V V
Recessive state differential input voltage −12,0 V ≤ V ≤ +12,0 V
CAN_L
V −3,0 +0,5
Diff
range
−12,0 V ≤ V ≤ +12,0 V
CAN_H
Dominant state differential input voltage −12,0 V ≤ V ≤ +12,0 V
CAN_L
V +0,9 +8,0
Diff
range
12,0 V ≤ V ≤ +12,0 V
CAN_H
Measurement setup according Figure 2:
R > 10 Ω (not present)
L
C = 0 pF (not present)
C = 0 pF (not present)
C = 0 pF (not present)
RXD
NOTE  A negative differential voltage may temporarily occur when the HS-PMA is connected to a media in which common
mode chokes and/or unterminated stubs are present. The maximum positive differential voltage may temporarily occur
when the HS-PMA is connected to a media while more than one HS-PMA is sending dominant and concurrently a ground
shift between the sending HS-PMAs is present.
When the HS-PMA implementation is in its low-power mode and bus biasing is inactive, then the
recessive and dominant state differential input voltage ranges according to Table 9 apply.
Table 9 — HS-PMA static receiver input characteristics, bus biasing inactive
Value
Parameter Notation Condition
Min Max
V V
Recessive state differential input −12,0 V ≤ V ≤ +12,0 V
CAN_L
V −3,0 +0,4
Diff
voltage range
−12,0 V ≤ V ≤ +12,0 V
CAN_H
Dominant state differential input −12,0 V ≤ V ≤ +12,0 V
CAN_L
V +1,15 +8,0
Diff
voltage range
−12,0 V ≤ V ≤ +12,0 V
CAN_H
Measurement setup according Figure 2:
R >10 Ω (not present)
L
C = 0 pF (not present)
C = 0 pF (not present)
C = 0 pF (not present)
RXD
NOTE  A negative differential voltage may temporarily occur when the HS-PMA is connected to a media in which common
mode chokes and/or unterminated stubs are present. The maximum positive differential voltage may temporarily occur
when the HS-PMA is connected to a media while more than one HS-PMA is sending dominant and concurrently a ground
shift between the sending HS-PMAs is present.
8 © ISO 2016 – All rights reserved

5.5 Receiver input resistance
The implementation of an HS-PMA shall have an input resistance according to Table 10. Furthermore,
the internal resistance shall meet the requirement given in Table 11. Figure 4 shows an equivalent
circuit diagram.
Figure 4 — Illustration of HS-PMA internal differential input resistance
Table 10 — HS-PMA receiver input resistance
Value
Parameter Notation Condition
Min Max
kΩ kΩ
Differential internal resistance R 12 100
Diff
−2 V ≤ V ,
CAN_L
R ,
CAN_H
Single ended internal resistance 6 50
V ≤ +7 V
CAN_H
R
CAN_L
R = R + R
Diff CAN_H CAN_L
Table 11 — HS-PMA receiver input resistance matching
Value
Parameter Notation Condition
Min Max
V , V :
CAN_L CAN_H
a
Matching of internal resistance m −0,03 +0,03
R
+5 V
a
The matching shall be calculated as m = 2 × (R − R )/(R + R ).
R CAN_H CAN_L CAN_H CAN_L
5.6 Transmitter and receiver timing behaviour
The timing is defined under consideration of the test circuit that is shown in Figure 2. The parameters
are given in Tables 12, 13 and 14 and shall be measured at the RXD output and TXD input of the HS-PMA
implementation as well as on the differential voltage between CAN_H and CAN_L.
Figure 5 shows how to measure the timing in the signal traces.
Key
t = 1 000 ns if the implementation of the HS-PMA supports bit rates of up to 1 Mbit/s
Bit(TXD)
t = 500 ns if the implementation of the HS-PMA supports bit rates of up to 2 Mbit/s
Bit(TXD)
t = 200 ns if the implementation of the HS-PMA supports bit rates of up to 5 Mbit/s
Bit(TXD)
Figure 5 — HS-PMA implementation timing diagram
Table 1
...