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Universidade Técnica de Lisboa - Instituto Superior Técnico Departamento de Engenharia Electrotécnica e de Computadores
Área Científica de Computadores
Lisboa, Portugal2013
MEE
Sistemas EmbebidosEmbedded Systems
Rui Manuel Rodrigues [email protected]
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Introduction
Goals
Organization
Program
Assessment
Bibliography2
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Goals
To study the architectures, systems and technologies of embedded systems capable of probing the real-world and interacting with it.
Improve students’ culture on computer architectures, operating systems and interfacing, with particular emphasis on real-time systems.
The most profound technologies are those that disappear. They weave themselves into the fabric of everyday life until they are indistinguishable from it.
Mark Weiser in Scientific American, 1991
Computers are not primarily used for solving mathematical problems or data processing, but instead are components in complex systems.
Terry Winograd in Communication of the ACM, 1979
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Organization
L e c t u r e s ( P r o f . R u i R o c h a )
S c h e d u l e : Tuesday (14:10-15:30) ; Wednesdays (14:10-15:30)
L a b s ( P r o f . C a r l o s A l m e i d a & R u i R o c h a )L a b s e s s i o n s - 3 h o u r s ( f o r t n i g h t l y ) 1 p r o j e c t - e a c h g r o u p ( 2 ) w i l l t a c k l e a d i f f e r e n t p r o b l e m
P a r t 1 - h a n d l i n g t h e h a r d w a r e w / b a s i c s o f t w a r eP a r t 2 - u s i n g a R T O S
S u p p o r tb y e - m a i l : r u i . r o c h a @ l x . i t . p tO f f i c e : T B A o n t h e c o u r s e w e b s i t e
I n f o r m a t i o n s ( w e b )4
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Programme
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Basics of Embedded Computing Introduction
Embedded & Real-time Systems characterization Fallacies and Pitfalls, Challenges
CPUs Typical CPUs ISA architectures
System’s ArchitectureMemory, Bus, I/O
Development Platforms & tools
Multiprogramming and OSMultitaskingOperating Systems: structure, main functions, ... SchedulingSynchronization and IPCMechanisms, typical primitives, examples
FreeRTOS Task managementSynch. & IPCInterrupts and Device HandlersExamples of primitivesUse cases examples
Real-time issuesscheduling, priority inversion
Design methodologiesAbstraction levels, specs, design approaches, integrationExamples
Networked embedded systems Comm. in Embedded Systems
Ethernet, CAN, ZigbeeMain issues: networking, power management, ...Main protocols: data-link, time-synch, ...
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Lectures and assignments schedule
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See https://fenix.ist.utl.pt/disciplinas/semb/
2012-2013/1-semestre
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Assessment
Final Exam (minimum grade 8,5)
1st Period - Jan, 11 2014
2nd Period - Feb, 1 2014
Lab (minimum grade 9,5)
Project delivery
Part I - Nov, 8 2013; Part II - Dec, 20 2013
Oral assessment - Jan, 3 & 4 2014
Final Grade
NF = 0,5*EF + 0,5*Lab
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Bibliography
Main Textbooks Wayne Wolf; Computers as Components: principles of embedded computing system design, Morgan Kaufman, 2000.
Richard Berry; Using the FreeRTOS Real Time Kernel, FreeRTOS 2009. http://shop.freertos.org/RTOS_primer_books_and_manual_s/1819.htm
Complementary TextbooksRichard Zurawski (ed.); Embedded Systems Handbook, 2nd Ed., Vol.I - Embedded Systems Design and Verification, CRC Press, 2009
Richard Zurawski (ed.); Embedded Systems Handbook, 2nd Ed., Vol.II - Networked Embedded Systems, CRC Press, 2009
Phillip Laplante; Real-time systems design and analysis: an engineer's handbook, IEEE Press, 1993.
Michael Barr; Programming Embedded Systems in C and C++. O'Reilly & Associates, Inc, 1999.
Other documentsManuals and Tutorials … see the website for some references.
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Maths is not everything
Embedded & Real-time Systems
Introductory Notes:
Embedded SystemsReal-time Systems
Real-time Systems’ CategoriesPitfalls and Fallacies
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Embedded & Real-time SystemsDefinition of an Embedded System
The “computer” is a “component” of a more complex system.
This system is not designed for a generic utilization but rather for a special purpose.
The “computer system” physically interact with the real world.
RTSs have requirements on the timing of these interactions.
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Embedded & Real-time SystemsReal-time Systems
A Real-time System:
Produces results that are correct both in logical and time domains
a system is said to have real-time properties if its results are logically correct and were produced at the right time.
a correct response given out of its expected time is considered incorrect from a real-time point of view!
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Embedded & Real-time SystemsReal-time System’s Categories
Hard Real-time System:Every response respects a strict time specification
otherwise it represents a system failure.Example: car airbag
Firm Real-time System:Infrequent deadline misses are tolerable, but may degrade the system's quality of service.
The usefulness of a result is zero after its deadline.Example: video game, non critical industrial process
Soft Real-time SystemMost of its responses fall into a given time interval specification
but not meeting this deadline does not represents a system failure -> occasional timing failures are acceptable
Example: travel booking systems
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Embedded & Real-time SystemsPitfalls and Fallacies
Real-time means ad-hoc approaches
Real-time is equivalent to speed
Technology will eventually solve real-time problems
Real-time systems must use Assembly as the programming language
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