1. Automotive Communication Network Trends
Gary Miller
Automotive Application Engineer
0C14I

2. Gary Miller Product Marketing Manager Previous experience
32-bit Automotive Body
Previous experience
Hardware
EMC engineer on McDonnell Douglas F-15
Analog and digital design for visual flight simulation
Software
Ford -> Visteon: PowerTrain software
13+ years automotive experience
Low level drivers and operating systems
Two patents
BSEE from University of Michigan
I am Gary Miller and yes, that was a self portrait! I took a few pictures and never found one I liked, so just used this one.
I am a technical applications engineer supporting the Renesas 32-bit devices.

3. Renesas Technology & Solution Portfolio
The wealth of technology you see here is a direct result of the fact that Renesas Electronics Corporation was formed on April 1, 2010 as a joint venture between Renesas Technology and NEC Electronics — Renesas Technology having been launched seven years ago by Hitachi, Ltd. and Mitsubishi Electric Corporation. There are four major areas where Renesas offers distinct technology advantage.
--The Microcontrollers and Microprocessors are the back bone of the new company. Renesas is the undisputed leader in this area with 31% of W/W market share.
--We do have a rich portfolio of Analog and power devices. Renesas has the #1 market share in low voltage MOSFET solutions.
--We have a rich portfolio of ASIC solution with an advanced 90nm, 65nm, 40nm and 28nm processes. The key solutions are for the Smart Grid, Integrated Power Management and Networking
--ASSP: Industry leader for USB 2.0 and USB 3.0. Solutions for the cell phone market
-- Memory: #1 in the Networking Memory market

4. Microcontroller and Microprocessor Line-up
2010
2012
1200 DMIPS, Superscalar
1200 DMIPS, Performance
Automotive & Industrial, 65nm
600µA/MHz, 1.5µA standby
Automotive, 40nm
500µA/MHz, 35µA deep standby
500 DMIPS, Low Power
32-bit
Automotive & Industrial, 90nm
600µA/MHz, 1.5µA standby
165 DMIPS, FPU, DSC
165 DMIPS, FPU, DSC
Industrial, 90nm
500µA/MHz, 1.6µA deep standby
Industrial, 40nm
200µA/MHz, 0.3µA deep standby
Those of you who have attended the last DevCon in 2010, the left side of this slide should look familiar. In 2010, as a result of the merger between Renesas Technology and NEC Electronics, we started offering MCU solutions based on these five cores. The R8C and 78K were mainly focusing on low end 8/16 bit applications in both automotive and industrial applications,. The RX with 32 bit CISC core was mainly offering solutions for Industrial and consumer applications.  The high-end V850 and SH cores with 32-bit RISC architecture were very successful in high end automotive and industrial applications.
Within 6 months after the merger, we launched a brand new 16-bit product family named RL78, combining the low power flash technology and the CPU core from NEC’s 78K product line and innovative peripherals from Renesas’ R8C product family. The RL78 family is a great example of the synergy effect of this merger. The RL78 is now our main focus product line for cost sensitive low power applications. It consumes only 144uA/MHz power in active mode and only 0.2uA in standby mode. With up to 44DMIPS throughput, it offers much higher performance compared to any other 8/16 microcontrollers in the market place.
The RX family continues to be our flagship 32-bit family for Industrial and consumer applications. With 100 MHz single cycle flash, 1.65DMIPS/MHz throughput and packed with connectivity peripherals it  is ideal for digital signal controller applications. Since its introduction in 2009, we are rapidly expanding the RX product line. Now we have more than 500 different RX MCUs covering from 32KB to 2MB flash memory options.
Similar to the RX, we have recently announced the launch of our next generation high-end 32 bit microcontroller architecture for automotive applications. The new family is called RH850 and provides a next-generation migration path to automotive customers currently using V850 or SH in their application. For Industrial customers currently using V850 or SH, the migration path is the RX product family. Very soon we will launch a 240MHz RX product line which can cover the need of Industrial customers requiring more than 100MHz performance.
So, in summary, from 2013 and beyond, we will mainly be focusing on the three CPU cores, RL78, RX, and RH850, to cover the broad spectrum of the industrial and automotive application space, and we will continue to support legacy architectures like R8C, 78K, SH, and V850 for existing customers.  
25 DMIPS, Low Power
Industrial & Automotive, 150nm
190µA/MHz, 0.3µA standby
44 DMIPS, True Low Power
8/16-bit
Industrial & Automotive, 130nm
144µA/MHz, 0.2µA standby
10 DMIPS, Capacitive Touch
Industrial & Automotive, 130nm
350µA/MHz, 1µA standby
Wide Format LCDs

5. ‘Enabling The Smart Society’
Challenge: “Automotive communication protocols are changing rapidly. The communication environment is growing quickly as users want access to more information available in-vehicle. Bandwidth requirements are dramatically increasing because of new functionality, more interaction between modules, and bandwidth-hungry signals such as video.” 
Solution:
“This class will discuss the Automotive trends and how Renesas understands the requirements to meet future demands.”
Automotive networking is changing.

6. Agenda Terminology & Concepts Automotive Networks – Today & Tomorrow
Security in Automotive
Energy Efficiency Trends
Summary

7. Terminology & Concepts
The terminology and concepts in the following slides will be used in the rest of the presentation.
Depending on the group knowledge will dictate the speed at which you can cover this section.
The intent is to cover this quickly. If there are any questions later in the presentation you can come back to these slides.

8. Bus Access Single Master – Multiple Slaves Configuration
Master node controls bus access
Establishes timing
Initiates all communications
Slave node(s) react to the master node
Cannot initiate communications
Peer-to-Peer / Multi-Master
Any node can initiate communications
Requires means to control access to the bus
Token Passing
Time Division Multiplexing (TDM)
Agreed, assigned time to transmit
“Arbitrated” Access
CSMA variants
Question: Can anyone give an example of a single master, and/or multi-master?
Answer: LIN is single master. CAN is multi-master. Most Automotive networks are multi-master

9. Arbitrated Access: CSMA
CS = Carrier Sense — Nodes wait for period without bus activity (IDLE time) before initiating communication
MA = Multiple Access — Every node has an opportunity to initiate communication
CSMA-CD = CSMA with Collision Detection
Stop communicating when collision is detected
Try again from the start
IEEE Ethernet (Half-Duplex Operation)
CSMA-CA = CSMA with Collision Avoidance
Divide channel somewhat equally among all nodes
IEEE WiFi (not possible to listen while sending)
CSMA-CR = CSMA with Collision Resolution
Resolve collision situations as they happen
Highest priority message remains intact: sent without delay or retry
All lower priority messages must retry in next IDLE time
Scope capture:
Data spread out evenly
Characters with red are to highlight the significant parts of the acronym.
CSMA-CA:
Not possible to listen while sending, therefore collision detection is not possible.
CSMA-CR:
Question: Anyone think what Automotive serial communication uses this?
Answer: CAN
time

10. CSMA-CR: Non-Destructive Bitwise Arbitration
Dominant Bus State:
Any node attempts to drive the bus to its dominant state
bus = dominant
Recessive Bus State:
Bus assumes recessive state if no nodes are
driving bus to dominant state
Dominant “wins” over recessive
Typical Implementation - CAN transceiver
Active (transistor) drive to dominant state
Passive (resistor) pull to recessive state
Non-Destructive Bitwise Arbitration
Node stops transmitting when it loses arbitration
Loses arbitration: RX’d bit NOT EQUAL TX’d bit
Field in the message header
defines message priority
Main point: Dominant wins over recessive
Animation shows Node 2 losses arbitration then Node 3, so Node 1 continues

11. Event Driven vs. Time Driven
Data potentially grouped
time
Event Driven
Medium used only when necessary
Point when medium is accessible depends on current load
Unknown delay between when medium access is requested and when it is actually accessed
Time of message arrival is unknown
Medium might be overloaded
Time Driven
Point in time when medium is accessible is defined / guaranteed
Bandwidth utilization is known (duration of how long the medium is used)
Time of arrival is defined / guaranteed
Time Driven = Deterministic
Mostly used for safety critical programs
Data spread out evenly
First animation brings up just the words for event driven. Next step is to show the scope capture of serial communication. This explains the words better and the black and white scope plots are used in a few of the following slides.
Time Driven helps keep bus usage distributed over the bandwidth and allows consistent messaging.

12. TDMA: Time Division Multiple Access
Share the bus
Dividing into different time slots
Transmit in rapid succession each using its own time slot
Wireless
Slots assigned on demand in dynamic TDMA
2G cellular systems based on TDMA
Wired consumer
HSLAN over existing home wiring
power lines, phone lines and coaxial cables
Automotive
FlexRay
Before Automotive bullet is brought up
Question: What Automotive serial comm uses this?
Answer: FlexRay
FlexRay is similar to CSMA-CA, but FlexRay is not Dynamic

13. Physical Media: Signal Formats
Non Return to Zero (NRZ)
Logical Bit value:
bus state during the bit time
“1” = a specific bus state (e.g. low voltage)
“0” = a different specific bus state (e.g. high voltage)
Cannot extract clock, not inherently self-synchronizing
Manchester
direction of transition in the middle of the bit time
At least one transition during each data bit
Self clocking – clock can be recovered
More bandwidth required, more EMI
Bi-phase (Differential Manchester)
presence / absence of transition in middle of bit time
At least one transition every bit
Blue text shows the key differences.
Animation shows an example of each format

14. Physical Media: Bit Stuffing
NRZ Signaling Problem
How to maintain synchronization when a long string of the same bit value is transmitted?
Solution: Bit Stuffing
1 inverse polarity bit added (“stuffed”) after “n” identical bits
Forces a transition edge:
Synchronization
Escape reserved code words such as frame sync sequence
Drawbacks
Results in variable data rate
Reduces bus efficiency
escape special reserved code words such as frame sync sequences when the data happens to contain them

15. Topology Ring Star Bus Data travels around one direction
Each device acts as a repeater
Keeps the signal strong as it travels
Star
Each network host is connected to a central hub
All traffic passes through the central hub
Hub acts as a signal repeater
The pictures tell the whole story.
Most automotive serial communications use a BUS
Bus
Each node is connected to a single cable
Data travels in both directions to all nodes
If node address does not match intended address for the data, node ignores data

16. Automotive Networks – Today & Tomorrow

17. Automotive Networks Today
Data Rate (bps)
Relative Communication Cost Per Node
0.5
100M
25M
10M 1M
500K
Multiplexing
Distributed
Control
Multi-Media 1
2.5 5
20K
150M
MOST
Timing Master/TDMA
Designed for multimedia & infotainment
FlexRay
Multi-Master/Hybrid-TDMA
Fault Tolerant
This slide introduces the main serial communication networks used in Automotive today.
CAN
Multi-Master/CSMA-CR
Distributed Data
LIN
Master-Slave
Low cost I/O Interface
Source of cost for LIN, CAN, FlexRay, MOST: In-Vehicle Communication Networks: A Literature (Ugur Keskin).
Ethernet cost: Engineering estimate.

18. LIN / CAN / FlexRay Comparison
Features
Scalable, Deterministic, Slave Autobaud Detection (lower accuracy clock for slaves)
Scalable, Event-Driven
Time-Driven, Deterministic, Redundant, Fault-Tolerant, Global Time Base
Medium Access Control
Single Master
Multi-Master
CSMA-CR
Hybrid TDMA
Bit Coding
NRZ
NRZ w/ bit stuffing
Nodes
1 master, up to 15 slaves
4 – 20, depending on distance / topology
4 – 22, depending on distance / topology
Topology
Bus
Star or Bus
Typical Bus Speed
(bit/sec)
Low: up to 20Kbps
33Kbps to 500Kbps typical
1Mbps capable
2.5Mbps to 10Mbps
Data & Frame Size
1 - 8 bytes payload
44 bits overhead
0 – 8 bytes payload
47 bits overhead (std ID)
67 bits overhead (ext ID)
0 – 254 bytes payload
64 bits overhead
Bus Utilization Efficiency
(excluding idle time)
1 byte payload: 15%
8 byte payload: 52%
1 byte payload: 15% (std)
8 byte payload: 58% (std)
1 byte payload: 11% (ext)
8 byte payload: 49% (ext)
8 byte payload: 50%
254 byte payload: 97%
Physical Media
Single wire, 12V
Single or dual wire, 5V
Twisted pair, optical option
Industry Acceptance (NA)
Started: mid-1990’s,
Wide acceptance: early 2000’s
Started: early 1990’s
Wide acceptance: late 1990’s
Limited deployment in NA Wide acceptance in Europe
MCU Support
Standard UART or UART w/ extensions
CAN Peripheral
FlexRay Peripheral
Applications
Sensor / actuator interface to a master ECU (doors, mirrors, windows, motors, …)
Sharing data between ECU’s
High speed data sharing, distributed control, safety critical systems
LIN
CAN
FlexRay
Features
Scalable, Deterministic, Slave Autobaud Detection (lower accuracy clock for slaves)
Scalable, Event-Driven
Time-Driven, Deterministic, Redundant, Fault-Tolerant, Global Time Base
Medium Access Control
Single Master
Multi-Master
CSMA-CR
Hybrid TDMA
Bit Coding
NRZ
NRZ w/ bit stuffing
Nodes
1 master, up to 15 slaves
4 – 20, depending on distance / topology
4 – 22, depending on distance / topology
Topology
Bus
Star or Bus
Typical Bus Speed
(bit/sec)
Low: up to 20Kbps
33Kbps to 500Kbps typical
1Mbps capable
2.5Mbps to 10Mbps
Data & Frame Size
1 - 8 bytes payload
44 bits overhead
0 – 8 bytes payload
47 bits overhead (std ID)
67 bits overhead (ext ID)
0 – 254 bytes payload
64 bits overhead
Bus Utilization Efficiency
(excluding idle time)
1 byte payload: 15%
8 byte payload: 52%
1 byte payload: 15% (std)
8 byte payload: 58% (std)
1 byte payload: 11% (ext)
8 byte payload: 49% (ext)
8 byte payload: 50%
254 byte payload: 97%
Physical Media
Single wire, 12V
Single or dual wire, 5V
Twisted pair, optical option
Industry Acceptance (NA)
Started: mid-1990’s,
Wide acceptance: early 2000’s
Started: early 1990’s
Wide acceptance: late 1990’s
Limited deployment in NA Wide acceptance in Europe
MCU Support
Standard UART or UART w/ extensions
CAN Peripheral
FlexRay Peripheral
Applications
Sensor / actuator interface to a master ECU (doors, mirrors, windows, motors, …)
Sharing data between ECU’s
High speed data sharing, distributed control, safety critical systems
The terminology covered earlier is used extensively in this slide.
Each part of the animation exposes rows to be discussed.
LIN is normally called a bus, but since it is one master and many slaves it is in effect a STAR topoloty

19. Drivers of Change… User’s access to more information in vehicle
Bandwidth requirements increasing
New functionality
More interaction between modules
Bandwidth-hungry signals such as video
Requirements for safety and security on the bus
More safety related functions and security being emphasized
Control signals using messaging to a remote actuator
Diagnostics improvements requires more information
Driver assistance
Vehicle to vehicle
Vehicle to infrastructure
Autosar software architecture, separation
of functions from hardware implementation
Point here is why the existing networks are changing.
Each of these points is contributing to the evolution of the next generation networking.

20. Automotive Networks Tomorrow
Data Rate (bps)
Relative Communication Cost Per Node
0.5
100M
25M
10M 1M
500K
Multiplexing
Distributed
Control
Multi-Media 1
2.5 5
20K
150M
Ethernet & Ethernet AVB
Multi-Master/CSMA-CD
Leverage Consumer Technology & Standards
High Data Rates
MOST
Timing Master/TDMA
Designed for multimedia & infotainment
Safety critical functions over Ethernet?
FlexRay
Multi-Master/Hybrid-TDMA
Fault Tolerant
CAN FD ?
Start with Networks Today.
CAN i& safety critical are in RED because they are concerns/open discussions.
We go into CAN-FD and Ethernet more in the following slides
Ethernet has already started taking the place of FlexRay in European OEMs
CAN
Multi-Master/CSMA-CR
Distributed Data
LIN
Master-Slave
Low cost I/O Interface
Source of cost for LIN, CAN, FlexRay, MOST: In-Vehicle Communication Networks: A Literature (Ugur Keskin).
Ethernet cost: Engineering estimate.

21. CAN with Flexible Data Rate (CAN FD)
Higher bit rate possible once arbitration completed
After arbitration, only one node is transmitting…
CAN FD controllers backward compatible (CAN 2.0 A/B)
r0 bit changed to EDL = Extended Data Length
BRS = Bit Rate Switch
If r0 = ’recessive’, bit rate increased
If r0 =’dominant’, bit rate not switched.
ESI = Error State Indicator
’dominant’ by a node that is error-active
’recessive’ by a node that is error-passive.

22. CAN with Flexible Data Rate (CAN FD)
CAN FD Proposal
Increase bit rate after arbitration completes
Target: 2Mbps
Increase the data payload
From 8 bytes to 64 bytes / frame
OEM vision
CAN 2.0 A/B still used
CAN FD where bandwidth increase needed
Programming
Concerns
Requires revised / new ISO standard
Impacts CAN Protocol Controller: new design required
All nodes must have a CAN FD protocol controller
Minimum of Passive mode
Example:
2.0 data rate –500 kb/s
FD data rate –2 Mb/s
1 CAN 2.0, 8 bytes, no stuff bits –220 μs
1 CAN FD, 8 bytes, no stuff bits –100.5 μs
4 CAN 2.0, 8 bytes, no stuff bits –880 μs
1 CAN FD, 32 bytes, no stuff bits ≈ 200 μs
From GM - GM CAN FD SAE Presentation 0427 rev3.pdf
Higher bit rates appear possible, but require HW/SW changes (protocol controller)
Industry acceptance / standardization needed

23. Automotive Ethernet
High data rates – 10Mbps to 10+Gbps
100Mbps over unshielded single twisted pair cable
Full duplex communication capability
Options allow data rate (and cost) to match application requirements
Leverage widely available consumer / office / industrial infrastructure to reduce cost of ownership
Open standardization
Existing & proven hardware IP
Inexpensive & flexible cabling options
Proven TPC/IP protocol stack
Flexible configuration
Supports different topologies
Easily add nodes
Virtually no limit on number of nodes
Interoperability with external networks
Easily connects to Internet and Cloud
Main point is Ethernet has a lot of positives (in green).
Areas of concern are put up last, but next slides show plans to make it okay
Delivery not guaranteed
But if it is fast enough….
AVB Extension
Issue: Impact on cost-of-ownership by including stringent automotive requirements – reliability in extreme conditions (temperature, voltage…), EMC/EME, …

24. Ethernet AVB
AVB (Audio Video Bridging) is developed for synchronized low latency A/V streaming transmission
Time critical data (e.g. multimedia) and non-time-critical data carried over same Ethernet network
Established common clock source among nodes
Standards included in AVB
802.1AS Timing and Synchronization
802.1Qat Stream Reservation Protocol
802.1Qav Forwarding and Queuing for Time-Sensitive Streams
802.1BA Audio Video Bridging Systems
Ethernet AVB appears to be becoming the standard in Automotive
Some parts are in hardware, some in software. More is done in hardware to offload the CPU.

25. Future Network Electrical Architectures
Backbone (FlexRay / Ethernet)
Ethernet / MOST
CAN
LIN
Ethernet / FlexRay / CAN
Diagnostic
Connection
Vehicle
Gateway
One concept with a primary vehicle gateway to the diagnostic connection

26. Future Network Electrical Architectures
Backbone (FlexRay / Ethernet)
Ethernet / MOST
CAN
LIN
Ethernet / FlexRay / CAN
Second possible option to have three gateway devices. May be further down the road.
Gateway is crossed off in animation since it seems everyone is moving to Ethernet.

27. Security in Automotive
Switching modes to security since it is big part of the future of Automotive networking

28. Security: one of many Automotive applications
Safety-relevant messages…
Emergency Brake!
Calvin (from Calvin and Hobbs) is known for causing mischief
… must be secured! (so that they can be trusted)

29. Security-enabled Automotive MCU
Master in the system: has unrestricted accesses to all MCU resources
Main CPU
Application Domain
Application Services
New master in the system: controls a (small) set of specific but exclusive resources for security relevant tasks
Secure Domain
Security Services
Secure HW
Secret Data
Configuration / Parameter Files
CPU cannot access Keys in Secure Data area directly.
External Memory I/F
Communication I/F
Test / Debug I/F

30. Potential use Case: Encrypted CAN Messages
Application Domain
Main application loop
Process the message received
Prepare a message to send
Execution time
IRQ
IRQ
Secure Domain
Wait for a CAN message
Decrypt the mailbox
Encrypt the mailbox
Send the CAN message
Top (first part of animation) is normal CAN messages.
Talk through the secure domain from right to left.
a message is prepared to send, causes an interrupt to secure domain, then waits for next message to be received.
Secret keys are never seen in the application domain

31. Potential use Case: Boot Loader Verification
Application Domain
Initiate the application environment
Initiate the communication stack
Main application loop
HW Reset
Execution time
Secure Domain
Boot loader verification failed: break the application loop No
Calculate H as the hash value of the boot loader memory
Calculate H’ as the verification of the boot loader signature (prev. stored)
H’ == H?
Boot loader verification successful: prepare for next security service
Talk through a normal boot loader after power up before animation brings in secure domain operations.
This use case shows boot loader could go to main application before main application is verified …
Yes
Enables systematic background check with no impact on application domain timings

32. Security in Automotive applications: Renesas’ value proposition
The next generation of Renesas Automotive devices integrates a scalable range of security peripherals to support existing and emerging security requirements on a broad range of automotive applications
Security Peripherals for MCU with embedded Flash
Security Peripherals for Flash-less SoC
ICU-S
ICU-M2
ICU-M3
Crypto Engine
This slide shows the wide range of security being designed into Renesas devices.
There is a dedicated class that has time to go into the details of these.
ICU-S = Slave (no dedicated security CPU)
ICU-M = Master (dedicated CPU)
Crypto Engine on R-Car is high end
(low- to mid-end)
(mid- to high-end)
Low power
Low cost
Flexibility and performances
High-performance (stream ciphers)

33. Energy Efficiency Trends
Automotive will continue to improve gas mileage. Part of the solution is going to become more energy efficient

34. Energy Efficient Automotive Networks
Not all ECUs need to be used during the entire drive-cycle
Trade-off between:
Energy savings
ECU start-up time
Selectively set ECU’s into lower-power states
Pretended Networking
Partial Networking
Energy Savings
Start-Up Time
Trailer Module
Seat Module
Partial
Networking
Pretended networking is done already in vehicles. Partial networking makes sense for some modules (trailer, seat, etc)
Window Controller
Pretended
Networking
“Domain” controller

35. Pretended Networking Local Power Saving Intelligence
Each ECU independently decides when to enter / exit a lower power mode
MCU in sleep / stop mode - can be woken up quickly
No changes to Network Management layer
Compatible with other nodes not supporting this feature
Easy integration into existing networks
Uses existing / standard transceivers
Efficiently implemented in software using Renesas low power products
e.g. RH850/X1x
Pretended Networking is done now in Automotive
Example of cars in airport parking lot. Every key FOB (remote car door unlock) button push wakes up modes in vehicle. All vehicles wake up to listen and decode key.
Many modules have to wake up with each CAN bus communication.
Varying power saving effect, but seamless compatibility with existing networks

36. Partial Networking
Shutting-down & starting-up during normal bus communication
ECU’s or groups of ECU’s
Shuts down complete ECU (except transceiver)
MCU not powered
Increases wake-up time
Network master node(s) coordinate power saving intelligence
Changes Network Management Layer
Accommodate Partial Network Cluster (PNC)
Requires special / new transceivers
“Selective Wake Up” transceivers
ISO
ISO had global wakeup
ISO has wakeup pattern or frame
Slides says it all.
Partial networking is going to be used more in the future
Potentially large power saving effect, but at expense of changes to the network

37. Summary

38. Summary Automotive communication Trends for tomorrow
Terminology & Concepts
What is used today
Trends for tomorrow
Protocol changes
Security
Energy efficiency
Renesas is ready “Enabling the Smart Society”
Talk back through main ideas and where audience showed interest.

39. Questions?

40. ‘Enabling The Smart Society’
Challenge: “Automotive communication protocols are changing rapidly. The communication environment is growing quickly as users want access to more information available in-vehicle. Bandwidth requirements are dramatically increasing because of new functionality, more interaction between modules, and bandwidth-hungry signals such as video.” 
Solution:
“This class will discuss the Automotive trends and how Renesas understands the requirements to meet future demands.”
Do you agree that we accomplished the above statement?

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