Embedded Systems Introdution

• 1. Prof. Dr. Muhammad Iram Baig1

2. What is an Embedded System? A physical system that employs computer control for aspecific purpose, rather than for general-purpose computation Any device that includes a computer but is not itself a general-purpose computer Hardware and Software, part of some larger systems andexpected to work without human intervention. Often the user of the device is not even aware that a computer is present. Respond, monitor, control external environment using sensors &actuators. 2 3. A short list of embedded systems Anti-lock brakes Auto-focus cameras Automatic teller machines Automatic toll systems Automatic transmission Avionic systems Battery chargers Camcorders Cell phones Cell-phone base stations Cordless phones Cruise control Curbside check-in systems Digital cameras Disk drives Electronic card readers Electronic instruments Electronic toys/games Factory control Fax machines Fingerprint identifiers Home security systems Modems MPEG decoders Network cards Network switches/routers On-board navigation Pagers Photocopiers Point-of-sale systems Portable video games Printers Satellite phones Scanners Smart ovens/dishwashers Speech recognizers Stereo systems Teleconferencing systems Televisions Temperature controllers Theft tracking systems TV set-top boxes VCRs, DVD players Video game consoles Video phones Washers and dryers Life-support systems Medical testing systemsAnd the list goes on and on 3 4. Embedded System Applications AerospaceNavigation systems, automatic landing systems, flight attitude controls, engine controls, space exploration (e.g., the Mars Pathfinder).AutomotiveFuel injection control, passenger environmental controls, anti-lock braking systems, air bag controls, GPS mapping.Children's ToysNintendo's "Game Boy", Mattel's "My Interactive Pooh", Tiger Electronic's "Furby".CommunicationsSatellites; network routers, switches, hubs.HomeDishwashers, microwave ovens, VCRs, televisions, stereos, fire/security alarm systems, lawn sprinkler controls, thermostats, cameras, clock radios, answering machines. 4 5. Embedded System Applications IndustrialElevator controls, surveillance systems, robots.Office AutomationFAX machines, copiers, telephones, cash registers.MedicalImaging systems (e.g., XRAY, MRI, and ultrasound), patient monitors, heart pacers.PersonalPersonal Digital Assistants (PDAs), pagers, cell phones, wrist watches, video games, portable MP3 players, GPS.InstrumentationData collection, oscilloscopes, signal generators, signal analyzers, power suppliesComputer PeripheralsPrinters, scanners, keyboards, displays, modems, hard disk drives, CD-ROM drives.5 6. 6 7. Embedded Systems Hardware Embedded systems hardware is used for processing input to provide output in task specific fashionInput InterfaceInformation Processing SystemsOutput Interface7 8. Processors Micro-processors and Microcontrollers Key Requirements: Energy Efficiency High Code Density Combined Size of all instruction Characteristics of a particular instruction set8 9. Microprocessors CPU for computers No RAM, ROM, IO on CPU chip itself Example: Intel x86, Motorola 680x0 CPUDataBusRAMROMI/O PortsTimersSerial PortAddress Bus 9 10. Microcontrollers ? Basically microcontroller is a device whichintegrates a number of the components of a microprocessor system onto a single microchip. A Micro-controller combines onto the same microchip. The CPU coreCPURAMROMI/OTimersSerial Port Memory(both RAM and ROM) Parallel Digital I/Os other I/Os & more10 11. Components of a Micro-controller A Timer module to allow the micro-controllerto perform tasks for certain time periods A serial I/O port to allow data to flow between the micro-controller and other devices such as a PC or another micro-controller An ADC to allow the micro-controller to accept analogue input data for processing 11 12. Micro-controller12 13. Why Micro-controller? Low cost, small packaging Low power consumption Programmable, re-programmable Lots of I/O capabilities Easy integration with circuits For applications in which cost, power and space are critical Single-purpose 13 14. Architectures Von Neuman Only one Memory holds data + instructions Data and Program share the same bus and thesame memory, and so must have the same width. CPU Registers: PC, IR and other general purpose Bottleneck: Gettinginstructions interferes with accessing RAM 14 15. ArchitecturescontdHarvard Separate program bus and data bus Can be different widths! Pipelining Easy Allows 2 simultaneousmemory Fetches Greater memory Bandwidth More predictable Bandwidth Most DSPs use Harvard Architecture for streaming data. 15 16. ArchitecturescontdCISC - (Complex Instruction Set Computer) A large number of instructions each carrying permutation of the same operation Instructions provide for complex operations Different instructions of different format Different instructions of different length Many Addressing modes Requires multiple cycles for execution 16 17. ArchitecturescontdRISC- (Reduced Instruction Set Computer) Reduced set of Instructions for simple operations Pipeline Friendly Each instruction of fixed length Instructions that can be executed in a single cycle Large general purpose Register set Can contain data or addresses Load-store Architecture No Memory Access for data 17 18. Architectures RISC vscontdCISC18 19. Architecturescontd Super Scalar Multiple CPUs in a single Processor Processor decides at runtime about the instructions thatcan be executed parallel. (Complex HW) Instructions will be executed in an order different from the strictly sequential one with the restriction that the result must be correct. Execution policies: 1. In-order issue with in-order completion 2. In-order issue with out-of-order completion 3. Out-of-order issue with out-of-order completion Examples: Intels Pentium, IBM Power2, AMD K5, MIPS R10K, HP PA8500, Cyrix 6x8619 20. ArchitecturescontdVLIW (Very Large Instruction Word) Multiple CPUs in a single Processor Compiler decides about the instructions that canbe executed parallel and can be grouped in one bundle (ILP, Instruction Level Parallelism) Examples: i860 (dual mode: RISC and VLIW), TriMedia, SHARC, Itanium, EPIC, ST200, StarCore, Transmeta Crusoe, Xtensa20 21. CISC vs RISC vs SS vs VLIW CISCRISCSuperscalarVLIWInstruction sizevariable sizefixed sizefixed sizefixed size (but large)Instruction formatvariable formatfixed formatfixed formatfixed formatRegistersfew, some specialmany GPGP and rename many, many (RUU) GPMemory referenceembedded in many instrsload/storeload/storeload/storeKey Issuesdecode complexitydata forwarding, hazardshardware dependency resolutioncode scheduling, (compiler)Instruction flowEX M WBIF IDEX M WBIF IDEX M WBIF IDEX M WBIF IDIF IDEX M WBIF IDEX M WBIF IDEX M WBIF IDEX M WB EX M WBIF IDEX M WB EX M WB 22. Performance Comparison 23. Performance Comparisoncontd 24. Traditional Embedded Systems24 25. Components of Embedded Systems25 26. Simplified View of PIC MCUs 27. Few Examples of Embedded SystemsProduct: Hunter Programmable Digital Thermostat.Microprocessor: 4-bit27 28. Product:Vendo V-MAX 720 vending machine. Microprocessor: 8-bit Motorola 68HC11. 29. Product: Sonicare Plus toothbrush. Microprocessor: 8-bit Zilog Z8. 30. Product: Miele dishwashers. Microprocessor: 8bit Motorola 68HC05. 31. Product: NASA's Mars Sojourner Rover.Microprocessor: 8-bit Intel 80C85. 32. Product: CoinCo USQ-712 coin changer. Microprocessor: 8-bit Motorola 68HC912. 33. Product: Garmin StreetPilot GPS Receiver.Microprocessor: 16-bit. 34. Product: TIQIT Computers Matchbox PC. Microprocessor: 32bit AMD Elan SC410. 35. Product: Palm Vx handheld. Microprocessor: 32-bit Motorola Dragonball EZ. 36. Product: Motorola i1000plus iDEN MultiService Digital Phone. Microprocessor: Motorola 32-bit MCORE. 37. Product: Rio 800 MP3 Player.Microprocessor: 32-bit RISC. 38. Product: RCA RC5400P DVD player. Microprocessor: 32-bit RISC. 39. Product: IBM Researchs Linux wrist watch prototype. Microprocessor: 32-bit ARM RISC. 40. Product: Sony Aibo ERS-110 Robotic Dog.Microprocessor: 64bit MIPS RISC. 41. Embedded AutomotiveMore than 30% of the cost of a car is now in Electronics 90% of all innovations will be based on electronic systems41 42. Concluding Remarks Embedded computers are all around us. Many systems have complex embeddedhardware and software Embedded systems have pose many design challenges: design time, deadlines, power, etc Design methodologies help us manage the design process 43