Embedded Systems

1. Embedded Systems By Sushant Kumar

2. Structure of the seminar • Introduction • History of embedded systems • Characteristics • Embedded systems for meters

3. Introduction Part 1

4. What is an Embedded System ? An embedded system is a special-purpose computer system designed to perform a dedicated function

5. An Embedded system A generic embedded system

6. Why Embedded system ? • Performance • Technology Advances • CMOS VLSI dominates older technologies (TTL, ECL) • Computer architecture improvements • RISC, superscalar, RAID, … • Price • Simpler development • CMOS VLSI: smaller systems, fewer components • Higher volumes • CMOS VLSI : same device cost 10,000 vs. 10,000,000 units

7. Embedded system vs General Computer • Performs one or a few pre-defined tasks • Very specific requirements • Task-specific hardware and mechanical parts • Often mass-produced • Design engineers can optimize it

8. Embedded System Microprocessor Micro controller Micro controllers have built in peripherals and memory which reduces the size of the system

9. Application Areas • Signal processing systems • Real-time video, DVD players, Medical equipment. • Distributed control • Network routers, switches, firewalls, • “Small” systems • Mobile phones, home appliances, toys, smartcards, MP3 players, PDAs, digital cameras, sensors, pc keyboard & mouse • Modern cars: Up to 100 or more processors • Engine control unit • ABS systems (Anti Lock Brake systems) • Emissions control • Diagnostics and Security systems • Accessories (doors, windows etc)

10. History of Embedded Systems Part 2

11. Apollo Guidance computer The Apollo Guidance Computer, the first recognizable modern embedded systemdeveloped by Charles Stark Draper at the MIT Instrumentation Laboratory

12. Minuteman Missile 1966 • First mass-produced embedded system • Autonetics D-17 guidance computer • Built from transistor logic • Reduced prices on nand gate ICs from $1000/each to $3/each • Medicinal appliances • Avionics, such as inertial guidance systems, flight control systems • Cellular telephones and telephone switches • Home automation products

13. Other developments

14. Moore’s law

15. Characteristics of Embedded Systems Part 2

16. Characteristics of Embedded Systems • Interface • Complexity • Platform • Peripherals • Tools • Reliability • Volume

17. 1. Interface Interface No User Interface Full User Interface Performing user- defined PDA’s Dedicated to one Task Missile guidance system

18. 2. Complexity Complexity Simple systems Complex systems • Connected to a network • Touch screen • Real time constraints • Part of a critical operation • Use buttons,small character/ digit-only displays • simple menu system

19. 3. CPU Platform • Many different CPU architectures used in embedded designs such as ARM, MIPS, x86, PIC, 8051 etc… • Desktop computer market is limited to just a few architectures

20. CPU Platform… • PC/104 is a typical base for small, low-volume embedded system design. • Uses an embedded real-time operating system such as MicroC/OS-II, QNX or VxWorks

21. CPU Platform… • Very-high-volume embedded systems use the system on a chip (SoC), an application-specific integrated circuit (ASIC) • CPU core was purchased and added as part of the chip design.

22. 4. Peripherals • Serial Communication Interfaces • Universal Serial Bus (USB) • Networks: Ethernet, Controller Area Network • Timers:PLL(s), Capture/Compare and Time Processing Units • General Purpose Input/Output (GPIO) • Analog to Digital/Digital to Analog (ADC/DAC)

23. 5. Tools • Embedded system designers use compilers, assemblers, and debuggers • Utilities to add a checksum or CRC to a program • Emulator replaces the microprocessor with a simulated equivalent

24. 6. Reliability issues • System cannot be shut down for repair • Solutions involve subsystems with spares • system must be kept running for safety and monetary reasons

25. 7. Volume Volume High Volume Low Volume Minimizing cost is usually the primary design consideration Used when cost is not a major factor Performance and reliability constraints

26. Embedded systems for Meters Part 4

27. Electric power consumption • Electric power consumption is not constant whole day • Peak period is between 1 pm and 4 pm • System must be engineered to meet peak power

28. Limitations of the meter • Mechanical device • Prone to wear,shock • Maintains no record of time • Only Counts the number of rotations of the wheel

29. Demand Curve

30. Real power limitation • Ideally current and voltage are in phase • Every volt-ampere delivered becomes a watt of power used • Induction motors and lamp ballasts cause current to flow out of phase • Fewer actual watts are used than delivered

31. Ideal power curve

32. When current and voltage are not in-phase

33. Power factor penalty • Industrial customers must by contract maintain power factor • Power factor=Ratio of real power used to volt amperes delivered • Pay penalty if above some agreed upon values

34. Multi function meter • Extend for smaller commercial customer • Even for residences • Contract can be varied

35. Billing • Networked system can facilitate automation • No need to send personnel • Better accuracy and lesser burden

36. Design Fundamentals • Means of taking samples • Display • Communication subsystem • Non-volatile memory • Power supply • Stored program micro-controller

37. Hardware design

38. Choosing a micro-controller • Feature set • Code space • Data Space • Data converter • Real-time clock

39. Conclusion • A quiet revolution is in progress in the utility industry. • Static metering devices, have been in use for the better part of a century • Gradually being replaced with multi-rate, multifunction meters • Capable of more accurately accounting for utility usage.

40. References • www.maxim-ic.com • www.electronicsforu.com • www.refdesign.techonline.com • www.wikipedia.org • www.powerelectronics.com • www.ucpros.com • www.pdfserv.maxim-ic.com

41. For detailed report www.sushantkumar.wordpress.com/tech

42. Thank You 