Jaeyong Chung
System-on-Chips (SoC) Lab.
Incheon National University
Embedded System Design
Lecture 2
Introduction
What are embedded computing systems?
Characteristics of embedded systems
Challenges in embedded computing system design.
Design methodologies.
Chung EPC6071 2
What are embedded systems?
Chung EPC6071 3
Definition
Embedded computing system: any device that
includes an information processing system but is not
itself a general-purpose computer.
Chung EPC6071 4
Definition
Chung EPC6071
“Dortmund“ Definition: [Peter Marwedel]
Embedded systems are information processing systems
embedded into a larger product
Berkeley: [Edward A. Lee]:
Embedded software is software integrated with physical
processes. The technical problem is managing time and
concurrency in computational systems.
Cyber-Physical (cy-phy) Systems (CPS) are integrations of
computation with physical processes [Edward Lee, 2006].
Cyber-physical system (CPS) =
Embedded System (ES) + physical environment
5
Cyber-Physical System
Chung EPC6071
CPS = ES + physical environment
Embedded systems ("computers inphysical environments")Embedded systems
("small computers")
Cyber-physical systems
6
Cyber-Physical System
Chung EPC6071
Extreme view:
PhysicalCyber
Digital Controls Systems, ca. 1980
Cyber-Physical Systems, 2010+ !
7
Internet of Things (IoT)
Embedded System + Internet Connectivity on Things
Computers are often not so smart because
Insufficient information on the environment
IoT may allow computers to perceive the world real-time
Chung EPC6071 8
Real-time model of the world
Applications
Application Area: Automotive Electronics
© P. Marwedel, 2011
[Based on slide by J.Engblom]
Functions by embedded processing:
ABS: Anti-lock braking systems
ESP: Electronic stability control
Airbags
Efficient automatic gearboxes
Theft prevention with smart keys
Blind-angle alert systems
... etc ...
Today’s high-end automobile may have 100
microprocessors:
4-bit microcontroller checks seat belt;
microcontrollers run dashboard devices;
16/32-bit microprocessor controls engine.
Chung EPC6071 9
BMW 850i Brake and Stability Control System
Anti-lock brake system (ABS): pumps brakes to
reduce skidding.
Automatic stability control (ASC+T): controls engine
to improve stability.
ABS and ASC+T communicate.
ABS was introduced first---needed to interface to existing
ABS module.
Chung EPC6071 10
BMW 850i, cont’d.
brake
sensor
brake
sensor
brake
sensor
brake
sensor
ABShydraulic
pump
Chung EPC6071 11
Application Area: Avionics
© P
. M
arw
edel, 2
011
Avionics
Flight control systems,
anti-collision systems,
pilot information systems,
power supply system,
flap control system,
entertainment system,
And many more
Dependability is of outmost importance
Chung EPC6071 12
More Application Areas
©Photos: P. Marwedel
Railroad
Waterways
Structural Safety
Sensors + data analysis
Taipeh 101
Bridge at Vancouver
Kilauea, Hawaii
Möhne lake dam
Chung EPC6071 13
Industrial Production Systems
Chung EPC6071
Chemical Installation
High-speed Bonder(SMD/PCB)
14
Finger print sensors
Airport security systems
Access control
Smart cards
Dependability is of outmost importance
Authentication Systems
Chung EPC6071 15
Smart Home
© P. Marwedel
Zero energy building, generates as much energy as
it consumes
Provides safety and security
Supports owners
Provides maximum comfort
ambient assisted living
Chung EPC6071 16
Learning Thermometers
Chung EPC6071 17
Nest Lab
A home automation company
Founded by ex-apple engineers, Tony Fadell and Matt
Rogers, in 2010
Acquired by Google for $3.2 billion in cash
Learning Thermometers
Easy to use
Good design
벨브의신
Chung EPC6071 18
“아파트 ‘난방코딩’, 이런게 IoT 아닌가요?” –
Blotter.net
Medical Systems
For example:
Artificial eye: several
approaches, e.g.:
Camera attached to glasses;
computer worn at belt; output
directly connected to the
brain, “pioneering work by
William Dobelle”. Previously
at [www.dobelle.com]
Translation into sound;
claiming much better
resolution.
[http://www.seeingwithsound.c
om/etumble.htm]
Chung EPC6071 19
Smart Medicine
Diagnosis
Support of therapy
Evaluation
Risk analysis
Information about patients
Chung EPC6071 20
switch
power station
control
station
sensors and local control
Decentralized
Control
centralized control
long distance
communication
Local Process
control
Centralized control
and monitoring
21
© DFG-
Forschergrup
pe 1511, TU
Dortmund,
Wietfeld,
Rehtanz et
al.
Smart Grid
Chung EPC6071 21
Smart Beer Glass
8-bit processor
Capacitive sensor for fluid
level
Inductive coil for RF ID activation &
power
CPU and reading coil in the table. Reports the level of fluid in the glass, alerts servers when close to empty
Contact less transmission of power and
readings
© Jakob Engblom
Integrates several technologies:
Radio transmissions
Sensor technology
Magnetic inductance for
power
Computer used for
calibration
Impossible without the computer
Meaningless without the
electronics
Chung EPC6071 22
More Application Areas
© Graphics: P. Marwedel, 2011
Telecommunication
Consumer electronics
Robotics
Public safety
Military systems
Chung EPC6071 23
Consumer Electronics
Simple control: front panel of microwave oven, etc.
Canon EOS 3 has three microprocessors.
32-bit RISC CPU runs autofocus and eye control systems.
Digital TV: programmable CPUs + hardwired logic for
video/audio decode, menus, etc.
Chung EPC6071 24
Head Mounted Display
Oculus VR
Founded by a HMD designer, Palmer Luckey
After E3 demo, the company announced a Kickstarter campaign
Within 4 hours of the announcement, raised $250,000 funding
Chung EPC6071 25
Robotics
Chung EPC6071
NASA’s Mars Sojourner Rover
Sony Aibo ERS-110 Robotic Dog
26
Characteristics of embedded systems
Dependability
Efficiency
Real-time constraints
Reactive & hybrid systems
Dedicated systems
Security
Chung EPC6071 27
CPS/ES must be dependable,
Reliability R(t) = probability of system
working correctly provided that it was
working at t=0
Maintainability M(d) = probability of
system working correctly d time units
after error occurred.
Availability A(t): probability of system
working at time t
Safety: no harm to be caused
Security: confidential and authentic
communication
Dependability
Chung EPC6071 28
Efficiency
© Graphics: Microsoft, P. Marwedel, M. Engel, 2011
CPS & ES must be efficient
Code-size efficient
(especially for microcontroller)
Run-time efficient
Cost efficient
Energy efficient
Small form factor
Small weight (light)
Chung EPC6071 29
Importance of Energy Efficiency
© Hugo De Man (IMEC) Philips, 2007
Efficient software design needed, otherwise, the price for software flexibility cannot be paid.
Chung EPC6071 30
CPS & ES Hardware
CPS & ES hardware is frequently used in a loop
(“hardware in a loop“):
Cyber-physical systems (!)
© Graphics: Microsoft, P. Marwedel, 2011
Chung EPC6071 31
Real-time Constraints
© Graphics: Microsoft
t
execute
CPS must meet real-time constraints
A real-time system must react to stimuli from the
controlled object (or the operator) within the time
interval dictated by the environment.
“A real-time constraint is called hard, if not meeting that
constraint could result in a catastrophe“ [Kopetz, 1997].
All other time-constraints are called soft.
A guaranteed system response has to be explained without
statistical arguments [Kopetz, 1997].
Chung EPC6071 32
Real-time Systems & CPS
CPS, ES and Real-Time Systems synonymous?
For some embedded systems, real-time behavior is less important
(smart phones)
For CPS, real-time behavior is essential, hence RTS CPS
CPS models also include a model of the physical system
Chung EPC6071 33
Reactive & Hybrid Systems
© Graphics: Microsoft, P. Marwedel, 2011
Typically, CPS are reactive systems:
“A reactive system is one which is in continual
interaction with environment and executes at a pace
determined by that environment“
[Bergé, 1995]
Behavior depends on input and current state.
automata model appropriate,
model of computable functions inappropriate.
Hybrid systems
(analog + digital parts).
Chung EPC6071 34
Dedicated Systems
© Graphics: P. Marwedel, 2011
Dedicated towards a certain application
Knowledge about behavior at design time can be
used to minimize resources and to maximize
robustness
Dedicated user interface
(no mouse, keyboard and screen)
Situation is slowly changing here: systems become
less dedicated
Chung EPC6071 35
Security
Chung EPC6071
Defending against
Cyber crime („Annual U.S. Cybercrime Costs Estimated
at $100 Billion; …[Wall Street Journal, 22.7.2013])
Cyber attacks
Cyber terrorism
Cyber war (Cyber-Pearl-Harbor
[Spiegel Online, 13.5.2013])
Connectivity increases threats
entire production chains can be affected
local islands provide some encapsulation, but contradict idea
of global connectedness
36
Characteristics lead to corresponding challenges
© G
raphic
s: P
. M
arw
edel, 2
011
Challenges
Dependability
Energy Efficiency
Hardware properties, physical environment
Meeting real time requirements
Manufacturing Cost, Form factor, etc
Addressing any of these challenges add
a value to products
That value can be a game changer
Chung EPC6071 37
Dart: The world’s smallest Laptop Adaptor
Chung EPC6071 38
To be an ES expert
CS
Physics
EE
medicine, statistics, ME, biology
Knowledge from many areas must be available
Chung EPC6071 39
Design Methodologies/Flow
A procedure for designing a system.
Understanding your methodology helps you ensure
you didn’t skip anything.
Compilers, software engineering tools, computer-
aided design (CAD) tools, etc., can be used to:
help automate methodology steps;
keep track of the methodology itself.
Chung EPC6071 40
Traditional Design Flow
Start from some informal specification of functionality
and a set of constraints (time, power, cost, etc)
Generate a more formal specification of the
functionality based on some modeling concept (finite
state machine, data-flow, etc) using Matlab,
statecharts, C, C++, UML, VHDL, etc
Simulate the model to check the functionality. If
needed make adjustments
Choose an architecture (microprocessor, buses, etc)
such that the cost limits are satisfied and, you hope,
that time and power constraints will be fulfilled
Build a prototype and implement the system
Verify the system
Chung EPC6071 41
Traditional Design Flow (cont.)
If neither time nor power constraints are satisfied,
Go back to the architecture selection and choose another
architecture and start a new implementation
Or negotiate with the customer on the constraints
Chung EPC6071 42
Platform/Architecture Selection
Chung EPC6071 43
Platforms
(Mostly educational) Raspberry Pi, Aduino
System-on-chip
Processors
Microcontroller Architecture
ARM Cortex-M, Atmel AVR, AVR32, Intel 8051, etc
Microprocessor Architecture
FPGA
Microprocessors + FPGA
ASIC
IoT Enablers
Chung EPC6071 44
Bluetooth Smart (Low Energy)
Beacon (Background scan)
System-on-chips
smaller form factor
Lower power
Lower cost
Standard
These allow us to make
For example, a sensor swarm (i.e., many sensors)
https://www.youtube.com/watch?v=lniACfnHwVM
https://www.youtube.com/watch?v=uoOXRa8DXTM
IoT Hardware Platforms
Chung EPC6071 45
http://postscapes.com/internet-of-things-hardware
Tinyduino ($18) PanStamps ($19) RFduino (built-in BLE)
Summary
Embedded computers are all around us.
Many systems have complex embedded hardware and
software.
Embedded systems pose many design challenges:
design time, deadlines, power, etc.
Design methodologies help us manage the design
process.
Chung EPC6071 46
Top Related