Enabling Hybrid CAN and CAN FD Networks Tony Adamson Marketing - - PowerPoint PPT Presentation

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Enabling Hybrid CAN and CAN FD Networks Tony Adamson Marketing - - PowerPoint PPT Presentation

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Enabling Hybrid CAN and CAN FD Networks Tony Adamson Marketing Manager CAN / LIN / FlexRay NXP Semiconductors COVER PAGE SUBTITLE PLACEHOLDER COMPANY CONFIDENTIAL Why Automotive OEMs look to CAN FD Accelerate bandwidth in general operation

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SLIDE 1

COVER PAGE SUBTITLE PLACEHOLDER

COMPANY CONFIDENTIAL

Enabling Hybrid CAN and CAN FD Networks

Tony Adamson

Marketing Manager – CAN / LIN / FlexRay

NXP Semiconductors

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SLIDE 2

2.

October 28, 2015 COMPANY CONFIDENTIAL

Accelerate bandwidth in general operation

  • New and increasingly complex functions being introduced

+ Consolidation of computing power and increasingly distributed functions

Accelerate ECU Flashing in production

  • ECUs need to be flashed as quick as possible, without EMC constraints

Security introduction will require larger payloads

  • Signatures and encryption will not be feasible / insufficient using validated

technologies with 8-bytes (64-bit) frames.

CAN FD can address each of these problems – with a lower level of disruption than switching to alternate technologies.

Why Automotive OEMs look to CAN FD

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SLIDE 3

Core Problem: CAN FD and “Classic” CAN nodes cannot be mixed, while not all nodes need bandwidth acceleration

October 28, 2015 COMPANY CONFIDENTIAL

3.

Gateway

EPS Cl TCU ECU

Chassis ADAS Power Train

Gateway

EPS Cl ECU

Chassis ADAS Power Train

TCU

CAN FD Fast Branch

Classic CAN Network

  • Critical nodes at bandwidth limit

(either flashing or general use)

  • Network organised by function

Option 1: CAN FD Fast Branch

  • Networks organised by technology, not function.
  • Increased routing via gateway
  • Complicated firewall policies
  • Lacks scalability
  • Sub-optimal wiring solutions

Gateway

EPS Cl TCU ECU

Chassis ADAS Power Train

Option 2: Update complete branch

  • Network organised by function
  • Legacy nodes updated
  • Higher development costs
  • Lack of MCU availability // Higher cost of MCU

Challenges of Introducing CAN FD for General Operation

Disclaimer: network implementation choices are ultimately dependent on many factors (# of branches, nodes / branch, cable lengths).

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SLIDE 4

Wish list to introduce CAN FD in General Operation

  • Keep networks organized by function
  • Simpler security implementation
  • Optimal wiring solution for application
  • Apply CAN FD where bandwidth is critical and

leave legacy nodes untouched

  • Overcomes / limits challenge on MCU availability
  • Limits investment costs and any BoM cost increase
  • Classical CAN and CAN FD arbitrating against

each other on the bus

  • Scalable for future network upgrades
  • Need CAN FD in an additional node? Upgrade later on.

October 28, 2015 COMPANY CONFIDENTIAL

4.

Gateway

EPS Cl TCU ECU

Chassis ADAS Power Train

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SLIDE 5

Flashed ECU 2

5.

CAN FD Passive function allows Classic CAN to co-exist:

Transceiver set to partial networking mode with FD frame tolerance active during CAN FD flashing. ECU participates in general

  • peration as standard Classic CAN node

October 28, 2015 COMPANY CONFIDENTIAL

Hybrid Networks for ECU Flashing Use-case Only

External Programmer

MCU

CAN FD Capable

TRX

5+ Mbps Capable

CANH CANL

Flashed ECU 1 Legacy CAN ECU

MCU

CAN FD Capable

TRX

5 Mbps Capable

MCU

Classic CAN

TRX

1 Mbps Capable

OFF PN

CANH CANL CANH CANL

MCU

CAN FD Capable

TRX

5 Mbps Capable

CAN FD used only when ECUs flashed. General operation remains Classic CAN.

Device flashed @ 2-5-8Mbps, no EMC constraints.

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SLIDE 6

Limitations of FD Passive for General Operation

FD Passive Ideal Solution

Transceiver solution, which blocks CAN FD traffic reaching the Classic CAN controller. Transceiver solution, which blocks CAN FD traffic reaching the Classic CAN controller. Extension of partial networking – only active when ECU node is in partial networking sleep mode. Available in all power modes. Requires ECU software support for partial networking and network management modes. No software changes. Available in 14-pin Partial Networking transceivers only. Available in 8-pin and 14-pin variants, with or with out low power and partial networking modes. Requires changes to network management to put all Classic CAN devices into sleep mode, or to wake up. No new network management needed. CAN and CAN FD nodes to arbitrate seamlessly against each other on the bus.

October 28, 2015 COMPANY CONFIDENTIAL

6.

Any solution to be fully accepted in the industry must be:

  • Fully ISO compliant and not violate the rules of CAN (FD).
  • Be fully interoperable with AUTOSAR.
  • Ensure no messages are lost and all ECUs always stay in synch with the bus.
  • Handle all error scenarios on the bus.
  • Be true drop-in replacement of a standard HS-CAN transceiver.
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SLIDE 7

Legacy CAN ECU

7.

October 28, 2015 COMPANY CONFIDENTIAL

FD Shield Overview

Legacy CAN ECU

MCU

Classic CAN

TRX

1 Mbps Capable

CANH CANL

MCU

Classic CAN

TRX

CAN FD Capable HS-CAN Transceiver

TXD RXD TXD RXD CANH CANL

FD Shield is drop-in replacement for all types of HS-CAN transceivers.

  • Basic HS-CAN
  • with Standby Mode
  • with Sleep Mode
  • with Partial Networking Mode

No further hardware changes needed

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SLIDE 8

CAN FD node 1 RXD TXD CAN FD node 2 RXD TXD classic CAN node 3 RXD TXD

SOF ID28 ID27 ID26 ID25 ID24 ID23 ID22 ID21 ID20 ID19 ID18 RRS IDE FDF res BRS

ESI

CAN FD node 1 CAN FD node 2

CAN FD node 1 starts transmitting a CAN FD frame

FD Shield

FD Shield Operation

October 28, 2015

8.

COMPANY CONFIDENTIAL

Classic CAN node 3

Switch to CAN FD frame format

FD Shield forces RXD to remain low

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SLIDE 9

CAN FD node 1 RXD TXD CAN FD node 2 RXD TXD classic CAN node 3 RXD TXD

FDF res BRS

ESI

6 dominant bits = stuff error

CAN FD node 1 CAN FD node 2

Error flag (blocked by FD shield) Wait for RXD=recessive! ISO11898-1: 10.4.4.3 Error delimiter … After sending an error flag, each node shall send recessive bits and monitors the bus until it detects a recessive bit…

FD Shield

October 28, 2015

9.

COMPANY CONFIDENTIAL

Classic CAN node 3

FD Shield Operation

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SLIDE 10

CAN FD node 1 RXD TXD CAN FD node 2 RXD TXD classic CAN node 3 RXD TXD

ACK

CRC delimiter

SOF

CAN FD node 1 CAN FD node 2

FD shield releases RXD during ACK slot RXD now represents the bus! 1bit recessive + 7 bit error delimiter (ED) 1 bit ACK delimiter + 7 bit end of frame (EOF) 1 bit ACK delimiter + 7 bit end of frame (EOF) ISO11898-1: 10.4.2.7 ACK field …The ACK delimiter, …, shall be a recessive bit. … 10.4.2.8 EOF … consisting of seven recessive bits forming the EOF. 10.4.4.3 Error delimiter After sending an error flag, each node … monitors the bus until it detects a recessive bit. Afterwards, it shall start sending seven more recessive bits.

FD Shield

October 28, 2015

10.

COMPANY CONFIDENTIAL

Classic CAN node 3

FD Shield Operation

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SLIDE 11

CAN FD node 1 RXD TXD CAN FD node 2 RXD TXD classic CAN node 3 RXD TXD

ACK

CRC delimiter

SOF

CAN FD node 1 CAN FD node 2

FD shield releases RXD during ACK slot RXD now represents the bus! 1bit recessive + 7 bit error delimiter (ED) 1 bit ACK delimiter + 7 bit end of frame (EOF) 1 bit ACK delimiter + 7 bit end of frame (EOF) 3 bit intermission 3 bit intermission 3 bit intermission

FD Shield

October 28, 2015

11.

COMPANY CONFIDENTIAL

Classic CAN node 3

FD Shield Operation

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SLIDE 12

CAN FD node 1 RXD TXD CAN FD node 2 RXD TXD classic CAN node 3 RXD TXD

ACK

CRC delimiter

SOF

CAN FD node 1 CAN FD node 2

Classic CAN (node 3) starts transmitting a classic CAN frame

FD Shield

October 28, 2015

12.

COMPANY CONFIDENTIAL

Classic CAN node 3

All nodes remain constantly synchronized Classic CAN and CAN FD ECUs can immediately arbitrate to send the next frame No interruption between messages No complicated bit synchronisation

FD Shield Operation

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SLIDE 13

A “Shielded” Classic CAN controller can participate in the general network communications via Classic CAN with CAN FD or any other “Shielded” Classic CAN controllers. Implications:

  • A Classic CAN controller will be error passive most of the time, if the majority of frames are

CAN FD frames.

  • Receive error counter is increased multiple times with each CAN FD frame.
  • Transmit error counter is not affected, thus no risk of entering “bus off”.
  • Error frames let the CAN FD shield release RXD / TXD immediately.
  • A “shielded” classic CAN controller participates in the global error scenario and thus stays in synch.
  • NXP has a specific solution for reporting errors for the Classic CAN controller, when required.
  • Details are given in NXP’s technical report TR1406.

October 28, 2015

13.

COMPANY CONFIDENTIAL

FD Shield Operation

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SLIDE 14
  • No ISO conformance issues when using FD Shield technology
  • Collaboration with conformance testing house confirming FD Shield’s compliance

to all rules of ISO11898-1 and -2.

  • FD Shield evaluated vs. ISO “CAN FD Tolerant” test specification.
  • Evaluation of NXP’s FD Shield Technical Paper already confirms no issues!
  • Fully compatible with AUTOSAR specifications v4.2.1 and v4.0.3
  • Vector confirm no issues when operating AUTOSAR in combination with NXP’s FD Shield,

and no issues with ERROR_PASSIVE state (is not used by high layers of software).

14.

October 28, 2015 COMPANY CONFIDENTIAL

Industry Support and Validation of FD Shield

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SLIDE 15
  • No additional network management required, like FD Passive.
  • True arbitration of CAN and CAN FD on a network.
  • No complicated bit synchronization required.
  • No loss of frames or waiting, and network remains in-synch.
  • Re-use legacy ECUs in your CAN FD network with a drop-in replacement

CAN transceiver.

  • Faster adoption of CAN FD by partial upgrades of network branches,

upgrading as required.

  • Lower investments when making transition.
  • Keep network topology organized by function.
  • The lowest cost option for CAN FD Tolerance.
  • No changes to MCU or hardware layout.
  • No software effort to upgrade.

October 28, 2015 COMPANY CONFIDENTIAL

15.

  • Vs. Alternative Solutions:

Towards Automotive Manufacturers: Towards Automotive Tier-1s:

Value Proposition of FD Shield

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SLIDE 16

Implementing A Hybrid Network

Evaluating a network for most effective CAN FD introduction with Vector’s CANoe tool

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SLIDE 17
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SLIDE 18
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SLIDE 19
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SLIDE 20

Unchanged

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SLIDE 21
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SLIDE 22

Summary and Key Messages

  • Enabling Classic CAN and CAN FD ECUs to co-exist on the same bus can save the automotive value

chain a lot of work when moving to higher bandwidth in vehicles

  • Hybrid networks provide more elegant solutions considering scalability, security and investments
  • FD Shield enables this co-existence, as a drop-in replacement CAN transceiver, making a Classic CAN

ECUs “CAN FD tolerant”, without any further hardware or software changes.

  • More than a purely theoretical solution, FD Shield is validated by key industry partners against ISO and

AUTOSAR for compliance, and available in silicon implementation.

  • Existing CAN networks can be analyzed with off-the-shelf tooling for upgrading options, simulated within

Vector’s CANoe tool and realized with NXP’s FD Shield.

October 28, 2015 COMPANY CONFIDENTIAL

22.

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SLIDE 23

October 28, 2015 COMPANY CONFIDENTIAL

23.

Come visit our booth!

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SLIDE 24