ID 210C: Introduction to CAN/LIN Solutions

Renesas Electronics America Inc.

Sridhar Lingam

Product Marketing Manager

12 October 2010

Version 10

2

Sridhar Lingam

Product Marketing Manager Renesas MCU CAN Solutions M16C/R32C, H8S/H8SX Product Families TFT-LCD solution for H8S and H8SX

Education MSEE from the Clemson University, Clemson, SC

Work Experience 16 years experience with semiconductor Industry with focus on

Industrial applications Varied experience as Product Engineer, FAE and Product

Marketing Responsible for definition and Marketing of Memory & MCU

product families Previously worked at National Semiconductor,

STMicroelectronics & Atmel

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Renesas Technology and Solution Portfolio

Microcontrollers& Microprocessors

#1 Market shareworldwide *

Analog andPower Devices#1 Market share

in low-voltageMOSFET**

Solutionsfor

Innovation

Solutionsfor

InnovationASIC, ASSP& Memory

Advanced and proven technologies

* MCU: 31% revenue basis from Gartner "Semiconductor Applications Worldwide Annual Market Share: Database" 25 March 2010

** Power MOSFET: 17.1% on unit basis from Marketing Eye 2009 (17.1% on unit basis).

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Renesas Technology and Solution Portfolio

Microcontrollers& Microprocessors

#1 Market shareworldwide *

Analog andPower Devices#1 Market share

in low-voltageMOSFET**

ASIC, ASSP& Memory

Advanced and proven technologies

* MCU: 31% revenue basis from Gartner "Semiconductor Applications Worldwide Annual Market Share: Database" 25 March 2010

** Power MOSFET: 17.1% on unit basis from Marketing Eye 2009 (17.1% on unit basis).

Solutionsfor

Innovation

Solutionsfor

Innovation

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Microcontroller and Microprocessor Line-up

Superscalar, MMU, Multimedia Up to 1200 DMIPS, 45, 65 & 90nm process Video and audio processing on Linux Server, Industrial & Automotive

Up to 500 DMIPS, 150 & 90nm process 600uA/MHz, 1.5 uA standby Medical, Automotive & Industrial

Legacy Cores Next-generation migration to RX

High Performance CPU, FPU, DSC

Embedded Security

Up to 10 DMIPS, 130nm process350 uA/MHz, 1uA standbyCapacitive touch

Up to 25 DMIPS, 150nm process190 uA/MHz, 0.3uA standbyApplication-specific integration

Up to 25 DMIPS, 180, 90nm process 1mA/MHz, 100uA standby Crypto engine, Hardware security

Up to 165 DMIPS, 90nm process 500uA/MHz, 2.5 uA standby Ethernet, CAN, USB, Motor Control, TFT Display

High Performance CPU, Low Power

Ultra Low PowerGeneral Purpose

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Microcontroller and Microprocessor Line-up

Superscalar, MMU, Multimedia Up to 1200 DMIPS, 45, 65 & 90nm process Video and audio processing on Linux Server, Industrial & Automotive

Up to 500 DMIPS, 150 & 90nm process 600uA/MHz, 1.5 uA standby Medical, Automotive & Industrial

Legacy Cores Next-generation migration to RX

High Performance CPU, FPU, DSC

Embedded Security

Up to 10 DMIPS, 130nm process350 uA/MHz, 1uA standbyCapacitive touch

Up to 25 DMIPS, 150nm process190 uA/MHz, 0.3uA standbyApplication-specific integration

Up to 25 DMIPS, 180, 90nm process 1mA/MHz, 100uA standby Crypto engine, Hardware security

Up to 165 DMIPS, 90nm process 500uA/MHz, 2.5 uA standby Ethernet, CAN, USB, Motor Control, TFT Display

High Performance CPU, Low Power

Ultra Low PowerGeneral Purpose

CAN MCU Solutions

R8C/R32C/SH/RX

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Innovation

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Our CAN/LIN Solution

Renesas’ easy to design MCU CAN/LIN solutions provide highly reliable, expandable, and noise immune

interfaces for industrial applications using chip to chip communications.

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Agenda

CAN in Embedded Networks

What is CAN & it’s benefits?

Can Basics

What is LIN and it’s benefits?

Renesas MCU CAN Solutions

Q&A

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Key Takeaways

Reasons for using CAN and LIN

Benefits of CAN and LIN

Basics of CAN and LIN

General differences between CAN and LIN

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What is CAN ?

Controller – Area – Network

Developed in 1983 by Robert Bosch

To solve the networking issues in automotive

Main Benefits

Economical

Reliable

Real Time response

Scalable

Standards

CAN 2.0A (ISO11519)

Can 2.0B(ISO11898)

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CAN-Leading Choice for Embedded Networking

The main Reasons are Economical

– Low Wiring Cost

– Low Hardware Cost

Reliability

– Error Free Communication

– Immune to EMI/EMS

Availability

– Several 8/16/32 bit MCU available in the market

– Standard development tools

Scalability

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Question

Please give 3 reasons for the growing popularity of

CAN in embedded applications

Reliability (works well in noisy environment)

Economical ( Have low wiring costs)

Scalability

Availability

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Features and Benefits of CAN

Multiple Master Hierarchy

1 Mbps of Data transfer rate

0-8 Bytes of User Data

Unique mail box Identifiers

Acceptance Filtering by nodes

Provides Error Detection

Fault Confinement measures

Auto re-transmit if corrupted

Redundant Intelligent Systems

Real Time Response

Simplifies design requirements

Flexibility in System Design

Arbitration & Prioritization

Ensures high Reliability

Keeps the traffic undisturbed

Accurate communication link

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CAN and the 7-layer model

1. Physical Layer

2. Data Link Layer

3. Network Layer

4. Transport Layer

5. Session Layer

6. Presentation Layer

7. Application Layer

Standard CAN implementation

Partially implemented by higher-level CAN protocols (CANOpen)

ISA/OSI Reference Model

Managed in Hardware.

Dramatic Real-time advantage to

System Design

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Data Flow in CAN

Transmitting Node

MCU Firmware

Identifier [id_n]

Data [values_x]

CAN Peripheral

Tx Mail Box [id_n]

Data [values_x]

Rx Mail Box [id_c]

Rx Mail Box [id_b]

CAN Transceiver

Node Configured to

receive identifier

MCU Firmware

Identifier [id_n]

Data [values_x]

CAN Peripheral

Data [values_x]

CAN Transceiver

Rx Mail Box [id_c]

Rx Mail Box [id_b]

Rx Mail Box [id_n]

Node not Configured to

receive identifier

MCU Firmware

CAN Peripheral

CAN Transceiver

Rx Mail Box [id_d]

Rx Mail Box [id_b]

Rx Mail Box [id_c]

Rx Mail Box [id_a]

Data Frame is broadcast to the bus ][value ]id n_[ x_

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Start of Frame – 1-bit

Arbitration Field – 11-bits/29-bits

Control Field – 6 bits (2 reserved, 4 representing number of Data Field bytes)

Data Field – 0 to 8 BYTES

CRC – 15-bits

ACK Field – 1-bit/variable

End of Frame – 7-bits (recessive)

Data Frame

SOF

1

Identifier

11/29

ID exten

d 1

Rem

Req

1

EOF

7+

Data(Bytes)

0-8 bytes

CRC

15

ACK

1

Control

4

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Question

Why do most CAN applications use CAN 2.0A (11-bit

identifiers) and not CAN 2.0B (29-bit identifiers)?

Overall data bandwidth decreases

Decrease in reliability

Increase in worse case delay

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CAN Bus Characteristics

Dominant bits (0’s) override recessive bits (1’s) on the CAN bus.

100

101

000

Node 1

Node 2

Node 3

000

Node 2 Backs Off

Node 1 Backs Off

LSB…MSB

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Maintaining Synchronization

‘Bit Stuffing’ is applied to keep the bus synchronized Five bits of consecutive dominant or recessive bits inserts a bit

of the opposite polarity Resulting signal edge is used to establish timing synchronization

at all nodes Stuffed bits are managed by hardware

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Bus Access and Arbitration

The CAN protocol handles bus accesses according to the concept of “Carrier Sense Multiple Access with Collision Detection”

For a collision, messages are NOT destroyed!No bandwidth is wasted on collisions! The message with the higher priority wins bus access

– NDA – “Non-destructive Arbitration”

Each message has an identifier that determines the priority Each node defined by unique identifier to avoid collisions

AMP – “Arbitration by Message Priority”

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CAN and EMI

CAN-Bus(Differential Serial Bus)

CAN_L

CAN_H

EMI

V

t

Node CNode A Node B

U diff

CAN_H

CAN_L

(dominant level)

+ - + -

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CAN Baud Rate vs. Bus Length

Bus lines assumed to be

an electrical medium

(e.g. twisted pair)

40 100 1000 10,000

CAN Bus Length [m]0 10 200

1000500

105

Bit Rate

[kbps]20

50

200

100

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Error Detection in CAN

Error statistics depend up on the entire environment

Total number of nodes

Physical Layout

EMI Disturbance

CAN application example running at

2000 hours/year, 500 Kbps, 25% Bus load

Results in one undetected error in 1000 years

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Physical Layer

OpticalTransceiver

CAN_Txd

CAN_RxdOptical Fiber

CAN_Txd

CAN_RxdCA

NC

on

tro

ller

DifferentialTransceiver

CAN_Txd

CAN_Rxd

Physical CAN Bus(Differential, e.g Twisted Pair)

Physical CAN Bus(Differential, e.g Twisted Pair)

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Cables and Connectors

CAN does not specify the physical media

Common Wire Twisted pair Shielded twisted pair If optional power is needed: additional twisted pair

– A pair of “shielded twisted pair” Application specific

Common Connector 9-pin Dsub 5-pin mini style Terminal blocks Application specific (e.g. telephone jacks)

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What is LIN ?

Local Interconnect Network

A slower & low cost alternative to CAN

Developed by LIN Consortium in 2002

Developed as a sub-network of CAN to reduce the Bus Load

Applications

Automotive, White Goods, Medical – for sensors and actuators

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Features & Benefits of LIN

Complementary to CAN

Single Wire Implementation

Speed up to 20Kbps

Single Master/Multiple Slave

Based on common UART/SCI

Self Synchronization

Guaranteed latency times

Extends CAN to sub-nets

Reduce harness costs

Improves EMI response

No arbitration necessary

Reduces risk of availability

No external crystal

Deterministic & Predictable

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Typical LIN Network

ECU & Gateway

CAN

SCILIN phys IF

CANphys

IF

5V

Node A

SCI

Node B

XCVRSCI

XCVR

Node C

SCIXCVR

Node D

SCIXCVR

Simplex12V Operation

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LIN Message Frame

0 to 8 data fields checksum

message response

synch break 13 bit

synch field identifier

message header

Synchronization

Frame

Synchronization

Field

Identifier Byte Message

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LIN Physical Interface

VBAT8...18V

GND

recessivelogic ‘1’

dominantlogic ‘0’

60%

40%

Bus Voltage

Time

UARTRx

Tx

LIN Control Unit

master: 1kslave: 30k

Buscontrolled slope~2V/µs

Example capacitancesmaster: 2.2nFslave: 220pF

Usually managed by a

transceiver

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Taking account of Ground-Shift

Data timing

Sen

se v

olta

ge

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LIN Baud Rate Requirements

(1)The pre-synchronization accuracy in rev. 1.3 is ±15%, but this is

tightened to 14% in LIN 2.0

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Question

What are the reasons when LIN is preferred over CAN?

To save the bandwidth of another main bus

Size of Network is 16 nodes or less

When lower speed is acceptable

Economical

Single Master with multiple slaves

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LIN versus CAN

LIN versus CAN

Access Control Single Master Multiple Master

Max Bus Speed 20 Kbps 1 Mbps

Typical # nodes 2 to 16 4 to 20

Message Routing 6-bit Identifier 11/29-bit Identifier

Data byte/frame 2,4,8 bytes 0-8 bytes

Error detection 8-bit checksum 16-bit CRC

Physical Layer Single-wire Twisted-pair

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Renesas CAN/LIN Solutions

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Renesas MCU CAN Solutions

SH7216200MHz@3/5V

RX600100MHz@3V SH7264/62

144MHz@3V

New

SH7286100MHz@3/5V

R32C/117With FPU

64MHz@3/5V

R32C/118With FPU

64MHz@3/5V

R8C/2x20MHz@3/5V

M16C/2920MHz@3/5V

Single

CANMulti

CAN

Low End

Up to 128 KB Flash

1 CAN

48-64 pin

High End

Up to 1 MB Flash

1-2 CAN

176 pin

Mid End

Up to 1 MB Flash

1-2 CAN

100/144/176 pin

CAN API

Compatible

www.america.renesas.com/CAN

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Implementation of CAN in Renesas MCU

Common Control/Status

Registers

CAN 2.0A / CAN 2.0BProtocol Engine

CPUInterface

Message Buffer

AcceptanceFilter

Control Registers

16/32 Message Buffers

Up to 1Mbps data rate

INTs

Clock

Data

Control

RX

TX

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Renesas M16C LIN Roadmap

M16C/Tiny

M32C

R8C/3x

M16C

R32C

Common LIN API

Support for all

M16C ProductsUART LIN

Dedicated LIN

Hardware

M1

6C

Pla

tfo

rm

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CAN Development Kits for R8C & R32C– CAN-D Kit Two R8C/23 or R32C/118 Renesas Starter Boards Systec CAN protocol Analyzer included in the kit E8/E30a Debug Interface Up to 3 CAN interfaces with 32 mailboxes each Time-triggered CAN support All board specific APIs and drivers available in included CD Extensive third-party middleware support available Sample projects and

evaluation software– CAN API– LIN API

Renesas CAN Development Kit

RCDK8C (R8C), MSRP: $495

YRCDK32C (R32C), MSRP: $550

R32C CAN-D kit now available

Common API for all Renesas CAN MCU Solutions

www.america.renesas.com/CAN

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Innovation

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Questions?

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Feedback Form

Please fill out the feedback form! If you do not have one, please raise your hand

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Thank You!

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Appendix

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Serial Communications

CAN, LIN, RS-485, RS-232, SPI, I2C, etc. are all serial communications

Advantages No line-to-line timing skew Fewer wires lowering cable, connector, and design costs Saves on board space and power consumption per bit

Disadvantages Generally point-to-point Overhead above actual data payload that uses bandwidth Higher signal rates shorten transmission distances

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Transmission Topologies

Point-to-Point (Simplex) One transmitter and one receiver per line Transmission is possible only in one direction, i.e. unidirectional.

Multidrop (Distributed Simplex) point-to-point configuration with one transmitter and many

receivers Only unidirectional transfer is possible.

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Transmission Topologies

Multipoint (Multiplex) Many transmitters and many receivers per line. Transmission is possible in either direction, i.e. bidirectional.

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Number of CAN Nodes Built

0

100

200

300

400

500

600

700

800

Millions

1998 2000 2002 2004 2006 2008 2010

Year

CAN Nodes Built

Millions of Units

~Over 2 Billion Nodes Shipped YTD!!!*

Source: CiA (CAN-in-Automation): http://www.can-cia.org*; REA estimates

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A Typical 2-channel CAN Solution2-channel CAN MCU

CPU

CAN CAN

CAN Transceiver

CAN Transceiver

Lighting System

Motion Sensor

Temp Sensor

Motor Control

HVAC

Monitor

CAN Bus 1Low-Speed

CAN Bus 2High-Speed

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RS-485 vs. CAN

CAN equals RS-485? Similar costs Similar distances Similar electrical immunity Similar chip availability Similar connectors Same 32 nodes (loads) standard Duplex (4 wire) or Half-Duplex (2 wire) options available

RS-485 is used primarily due to Legacy.Remember 8051?

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2. Data Link Layer

RS-485 and the 7-layer model

1. Physical Layer

3. Network Layer

4. Transport Layer

5. Session Layer

6. Presentation Layer

7. Application Layer

Only Low Layer specification

Standard RS-485 implementation

Partially implemented by higher-level RS-485 protocols (i.e. MODBUS)

ISA/OSI Reference Model

Managed by CPU in Software

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CAN Protocol Versions

Two CAN protocol versions are available:

V2.0A (Standard) - 11 bit Message ID’s - 2048 ID’s available

V2.0B (Extended) - 29 bit Message ID’s - more than 536 Million ID’s available

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Termination Settings

High-Speed CAN (125Kbps+) For High-Speed CAN, both ends of the pair of signal wires (CAN_H and

CAN_L) must be terminated ISO 11898 requires a cable with a nominal impedance of 120 ohms

– 120 ohm resistors should be used for termination Only the devices on the ends of the cable need termination resistors

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Termination Settings

Low-Speed CAN (Up to 125Kbps) Each device on the network needs a termination resistor for each data

line: R(RTH) for CAN_H and R(RTL) for CAN_L Requires termination on the transceiver rather than on the cable The resistance of each resistor is calculated through several formulas

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An example of LIN Implementation

Renesas Electronics America Inc.