1. Large to small… Systems
Embedded Electronics
Large to small…
Systems
By Peter Faber, April/May 2015

2. Embedded Systems
Invisible computers, inside most of the devices we use, from a music player, a mobile phone, to cars, trains, medical equipment, and so on.
an embedded system special-purpose computer system, part of a larger system which it controls
More than humans on the planet, already
40 billion of such devices by 2020
99% of processors used in embedded systems
4 billion embedded processors sold last year
€71 billion global market in 2009, growth of 14%
Market size is about 100 times the desktop market

3. Embedded systems are everywhereo
Our daily lives depend on embedded systems

4. From your bathroom... Product: Sonicare Plus toothbrush.
Microprocessor: 8-bit Zilog Z8.

5. To Mars...
Product: NASA's Mars Sojourner Rover. Microprocessor: 8-bit Intel 80C85.

6. Big...

7. And small...

8. Characteristics of embedded systems
Single-functioned
Dedicated to perform a single function
Complex functionality
Often have to run sophisticated algorithms or multiple algorithms.
Cell phone, laser printer.
Tightly-constrained
Low cost, low power, small, fast, etc.
Reactive and real-time
Continually reacts to changes in the system’s environment
Must compute certain results in real-time without delay
Safety-critical
Must not endanger human life and the environment

9. Automotive Electronics
Level of dependency
Embedded systems:
90% future innovations
40% price
1970
1980
1990
2000
ACC Stop&Go
BFD
ALC
KSG
42 voltage
Internet Portal
GPRS, UMTS
Telematics
Online Services
BlueTooth
Car Office
Local Hazard Warning
Integrated Safety System
Steer/Brake-By-Wire
I-Drive
Lane Keeping Assist.
Personalization
Software Update
Force Feedback Pedal…
Electronic Injections
Check Control
Speed Control
Central Locking …
Navigation System
CD-Changer
ACC Adaptive Cruise Control
Airbags
DSC Dynamic Stability Control
Adaptive Gear Control
Xenon Light
BMW Assist
RDS/TMC
Speech Recognition
Emergency Call…
Electronic Gear Control
Electronic Air Condition
ASC Anti Slip Control
ABS
Telephone
Seat Heating Control
Autom. Mirror Dimming
Automotive industry
40% of the vehicle’s costs and 90% of new innovation related to software or electronics
100-fold increase of code lines in two decades
Software for monitoring and controlling car state, media players, database programs etc.
source: BMW

10. Automotive architecture example

11. Evolution of handsets and technology

12. Smartphone architecture example
White LED driver
LCDs
Application processor
Baseband ASIC
Mixed-Signal ASIC
Energy management ASIC
Position sensors
512 MB DDR DRAM
512MB NAND FLASH
2MPix camera module
64MB NOR FLASH
64MB SDRAM RF
Battery
Frame buffer ASIC
MMC
ARM9
UMA core
Keyboard
LED Flash
BT Module
SIM
IHF
Back-light LEDs
Charger

13. Architectures: Networked embedded systems
Distributed functionality
...
Distributed across networks
Several functions per processor
...

14. Application areas: critical vs. best-effort
Critical (e.g., avionics)
Based on worst-case assumptions
Static reservation of resources
Schedulability analysis and static scheduling
Simple execution platforms
Leads to overdesign (underutilization)
Best effort (e.g., multimedia, networks)
Based on average-case
Dynamic reservation of resources
Sophisticated architectures
Adaptive scheduling mechanisms
Leads to temporary unavailability
Bridging the gap: partitioned architectures

15. Graphical illustration of Moore’s law
1981
1984
1987
1990
1993
1996
1999
2002
Leading edge
chip in 1981
10,000
transistors
chip in 2002
150,000,000
Something that doubles frequently grows more quickly than most people realize!
A 2002 chip could hold about 15, chips inside itself

17. More Moore vs. More than Moore

18. Tubes to Chips: Integrated Circuits
Driven by Information Processing needs
IBM 701 calculator (1952)
IBM Power 5 IC
(2004)
Slide soruce: Krish Chakrabarty, Duke University

19. Tubes to Chips: Biochips
Driven by biomolecular analysis needs
Test tube analysis
Agilent DNA analysis
Lab on a Chip (1997)
Slide soruce: Krish Chakrabarty, Duke University

20. Tubes to Chips: Biochips, cont.
Automation
Integration
Miniaturization
Test tubes
Automation
Integration
Miniaturization
Robotics
Automation
Integration
Miniaturization
Microfluidics
Slide soruce: Krish Chakrabarty, Duke University

21. Biochip Architecture
Slide soruce: Krish Chakrabarty, Duke University

22. Embedded systems design problem
Find an implementation that can perform the computation such that the requirements are satisfied.
Embedded systems perform computations (software) that are subject to physical constraints (hardware)
Reaction to a physical environment: deadline, throughput, jitter
Execution on a physical platform: processor speed, power, reliability
The need for an embedded systems design discipline
Computer science separates computation from physical constraints
Computer engineering ignores computation

23. Traditional embedded systems design
Design and build the target hardware
Develop the software independently
Integrate them and hope it works
Does not work for complex systems !!!!

24. Embedded software: size and deployment

25. Embedded software: complexity growth

26. Increasing complexity (telecom example)

27. Design crisis 0.35µ 0.25µ 0.18µ 0.15µ 0.12µ 0.1µ Log Scale
Gates/cm2
Moore’s Law
Widening Gap
Design Productivity
Software Productivity
Technology (micron)

28. We need a better design methodology
Design methodology: the process of creating a system
Goal: optimize competing design metrics
Time-to-market
Design cost
Manufacturing cost
Quality, etc.
Design flow: sequence of steps in a design methodology.
May be partially or fully automated.
Use tools to transform, verify design.
Design flow is one component of design methodology. Methodology also includes management, organization, etc.

29. Abstraction and clustering
Transistor Model
Capacity Load
1970’s
cluster
Gate Level Model
1980’s
RTL
SDF
Wire Load
1990’s
IP Blocks
IP Block Performance
Inter IP Communication Performance Models
Clusters SW
Models
Year

30. Abstraction and clustering: Platforms
The “PC platform” makes development easier
x86 instruction-set architecture
fully specified set of buses and
a specified set of I/O devices
Similar platform definitions for specific embedded systems application areas
Output Devices
Input devices
Hardware Platform I O
Hardware
Software
Network
Software Platform
Application Software
Platform API

31. System-level design tasks Model of system implementation
Application model
System platform model
Application
model
Architecture
model
System-level design tasks
Constructive vs. improvement
Model of system implementation
Evaluation
Analysis vs. simulation
Software synthesis
Hardware synthesis

32. Typical design tasks: Mapping and scheduling
Given
Application: set of interacting processes
Platform: set of nodes
Timing constraints: deadlines
Determine
Mapping of processes and messages
Schedule tables for processes and messages
Such that the timing constraints are satisfied S2 S1 P1 P4 P2 m1 m2 m3 m4 P3 N1 N2
Bus
Schedule table
Deadline

33. Biochips design tasks
Allocation
Binding
Placement
Scheduling

34. Design-space exploration

35. Safety-Critical Systems
Safety is a property of a system that will not endanger human life or the environment.
A safety-related system is one by which the safety of the equipment or plant is ensured.
Safety-critical system is:
Safety-related system, or
High-integrity system
Our daily lives depend on embedded systems

36. Introduction to CANBUS

37. Presentation Goals CANBUS Introduction CANBUS Characteristics
What is CANBUS?
Who uses CANBUS?
CANBUS history
CANBUS timeline
CANBUS Characteristics
OSI Model
Physical Layer
Transmission Characteristics
Message Oriented Communication
Message Format
Bus Arbitration

38. What is CANBUS? CANBUS or CAN bus – Controller Area Network bus
An automotive serial bus system developed to satisfy
the following requirements:
Network multiple microcontrollers with 1 pair of wires.
Allow microcontrollers communicate with each other.
High speed, real-time communication.
Provide noise immunity in an electrically noisy environment.
Low cost

39. Who uses CANBUS? Designed specifically for automotive applications
Today - industrial automation / medical equipment

40. CANBUS History
First idea - The idea of CAN was first conceived by engineers at Robert Bosch Gmbh in Germany in the early 1980s.
Early focus - develop a communication system between a number of ECUs (electronic control units).
New standard - none of the communication protocols at that time met the specific requirements for speed and reliability so the engineers developed their own standard.

41. CANBUS Timeline 1983 : First CANBUS project at Bosch
1986 : CAN protocol introduced
1987 : First CAN controller chips sold
1991 : CAN 2.0A specification published
1992 : Mercedes-Benz used CAN network
1993 : ISO standard
1995 : ISO amendment
Present : The majority of vehicles use CAN bus.

42. CANBUS and the OSI Model
CAN is a closed network
– no need for security, sessions or logins.
- no user interface requirements.
Physical and Data Link layers in silicon.

43. Conventional multi-wire looms
CANBUS Physical Layer
Physical medium – two wires terminated at both ends by resistors.
Differential signal - better noise immunity.
Benefits:
Reduced weight, Reduced cost
Fewer wires = Increased reliability
Conventional multi-wire looms
CAN bus network
vs.

44. Transmission Characteristics
Up to 1 Mbit/sec.
Common baud rates: 1 MHz, 500 KHz and 125 KHz
All nodes – same baud rate
Max length:120’ to 15000’ (rate dependent)
© esd electronics, Inc. • 525 Bernardston Road • Greenfield, MA 01301

45. Message Oriented Transmission Protocol
Each node – receiver & transmitter
A sender of information transmits to all devices on the bus
All nodes read message, then decide if it is relevant to them
All nodes verify reception was error-free
All nodes acknowledge reception
CAN bus
© 2005 Microchip Technology Incorporated. All Rights Reserved.

46. Message Format Each message has an ID, Data and overhead.
Data –8 bytes max
Overhead – start, end, CRC, ACK

47. Example of Message Transaction

48. Bus Arbitration
Arbitration – needed when multiple nodes try to transmit at the same time
Only one transmitter is allowed to transmit at a time.
A node waits for bus to become idle
Nodes with more important messages continue transmitting
CAN bus
© 2005 Microchip Technology Incorporated. All Rights Reserved.

49. Lower value = More important
Bus Arbitration
Message importance is encoded in message ID.
Lower value = More important
As a node transmits each bit, it verifies that it sees the same bit value on the bus that it transmitted.
A “0” on the bus wins over a “1” on the bus.
Losing node stops transmitting, winner continues.

50. Summary
CAN bus – Controller Area Network bus
Primarily used for building ECU networks in automotive applications.
Two wires
OSI - Physical and Data link layers
Differential signal - noise immunity
1Mbit/s, 120’
Messages contain up to 8 bytes of data

51. Bus arbitration
A “0” (low voltage) on the bus by 1 node wins over a “1” (high voltage) on the bus.

52. Bus Arbitration Flowchart

56. Exercise
Test Your system is working up against the main ECU (my CAN system).
You’ll now figure out and program the following:
Each group will program their own ECU, to be placed somewhere in ”the car”.
Group 1 Marius & Jonathan: Dashboard ECU
Group 2 Narcis & Niroy: Engine ECU
Group 3 Martin & Georgi: Tyre System ECU
Group 1 Program a system that asks the engine for temperature and the Tyre System for pressure
And accepts emergency messages from both
Group 2 Program a system that sends temeratures on request and alarm for overheating
Group 3 Program a system that sends tyre pressure on request and alarm for very low pressure