Introduction to Embedded Software Development

1. Introduction to Embedded Software Development 1. Embedded System School of software Engineering 2005

2. Agenda • What is an embedded system? • Embedded system features • Embedded system Configuration • Embedded Hardware • Embedded Software

3. Agenda • What is an embedded system? • Embedded system features • Embedded system Configuration • Embedded Hardware • Embedded Software

4. What is an Embedded system? An embedded system is a large or small computer system that is built into a product, a piece of equipment or another computer system, and that performs some task useful to the product, equipment or system. It is a computer system that is progr -ammed to perform a particular task.

5. What is an Embedded system? Maybe you will say, " But all computers are programmed to perform tasks!" You are right, however an embedded system is programmed to perform its task from the time it is powered up until it is shut down. Its programming cannot be changed except in ways that its original programmer intended.

6. What is an Embedded system? An embedded system is a component of a larger system of some sort. Indeed, embedded systems may be nested within other embedded systems to arbitrary depth. Generally, the "higher level" embedded system is the more complex one, but this is not necessarily the case.

7. Examples of embedded systems • PDA • Microwave • Programmable washing Machine • Digital answering machine • GPS • Intelligent credit card • Cruise control • Car engine timing

8. Mars, December 3, 1999 Crashed due to uninitialized variable Examples of embedded systems • Industrial controller • Guided missiles • Digital TV • Flight controller • Measuring instruments • Medical instruments • Gaming devices • and on and on ……

9. Agenda • What is an embedded system? • Embedded system features • Embedded system Configuration • Embedded Hardware • Embedded Software

10. Embedded system features • Real time • Small sized • Low power • Cost effective • ……

11. What is Real Time? A real time system is one in which the correctness of the computations not only depends upon the logical correctness of the computation but also upon the time at which the result is produced. If the timing constr-aints of the system are not met, system fail-ure is said to have occurred. —— DonaldGillies

12. What is Real Time? Real time in operating systems: The ability of the operating system to provide a required level of service in a bounded response time. —— POSIX Standard 1003.1

13. Real-Time System • Correct function at correct time • Usually embedded • Often distributed • Deadlines • Hard real-time systems • Soft real-time systems

14. Hard vs. Soft Real Time • Hard real-time • Systems where it is absolutely imperative that responses occur within the required deadline. E.g. Flight control systems. • Soft real-time • Systems where deadlines are important but which will still function correctly if deadlines are occasionally missed. E.g. Data acquisition system.

15. Real-Time System • Applications (Hard) • Cars (Volvo S80 has 19 computers) • Aeroplanes (JAS) • Medical equipment • Space vehicles (Mars lander) • Military systems • Industrial automation

16. Real-Time System • Applications (Soft) • Games • DVD (Mpeg encoding) • Internet video and broadcasting • Telecom

17. Agenda • What is an embedded system? • Embedded system features • Embedded system Configuration • Embedded Hardware • Embedded Software

18. User Program Including Operating Programs Operating Hardware Hardware System Components System Embedded system Configuration Typical Computer system Configuration Typical Embedded system Configuration

19. A Typical Embedded System Real-Time Clock Algorithms for Digital Control Engineering System Interface Remote Monitoring System Data Logging Database Data Retrieval and Display Display Devices Operator’s Console Operator Interface Real-Time Computer

20. Agenda • What is an embedded system? • Embedded system features • Embedded system Configuration • Embedded Hardware • Embedded Software

21. Embedded Hardware • CPU • Intel x86 • PowerPC(Mac) G3,G4,G5 • SPARC, Alpha • ARM • MIPS • …… • DATA Wide • 8 Bit controllers(still!) • 16 Bit controllers(mainly) • 32 Bit controllers(start popular) • 64 Bit controllers(high performance)

22. Embedded Hardware • CPU Market

23. Embedded Hardware Example

24. Why worry about energy and power? Worry about • power + energy “Power is considered as the most important constraint in embedded systems”[in: L. Eggermont (ed): Embedded Systems Roadmap 2002, STW] Current UMTS phones can hardly be operated for more than an hour, if data is being transmitted.[from a report of the Financial Times, Germany, on an analysis by Credit Suisse First Boston; http://www.ftd.de/tm/tk/9580232.html?nv=se]

25. Agenda • What is an embedded system? • Embedded system features • Embedded system Configuration • Embedded Hardware • Embedded Software

26. Embedded Software ——The Goal • To create a modern computational systems science and systems design practice with • Heterogeneity • Resource constraints • Verifiability • Understandability • Concurrency • Composability • Time • Hierarchy

27. User Program Including Operating Hardware System Components Enet Serial host target Embedded Software features • Limited Resource • Real time • No clear borderline • between user program • and OS • Develop method Typical Embedded system Configuration

28. Embedded Software Architecture Today

29. Embedded Software Architecture Tomorrow

30. Homework • How to comprehend embedded system? • Which of the products you use are embedd -ed system? Please give out their functions. • What is embedded software features? • What is the difference between a typic computer system and embedded system?