Presentation on theme: "Embedded Systems: Introduction"— Presentation transcript:
1 Embedded Systems: Introduction Prof. Santanu ChaudhuryProf. Wajeb Gharibi
2 SyllabusOverview of Embedded Systems; Embedded System Architecture: Processor Examples - ARM, PIC, etc.; features of digital signal processor; SOC, memory sub-system, bus structure (PC-104, I2C etc.), interfacing protocols (USB, IrDA etc), peripheral interfacing; testing & debugging, power management; Embedded System Software: Program Optimization, Concurrent Programming, Real-time Scheduling and I/O management; Networked Embedded Systems: special networking protocols (CAN, Bluetooth); Applications.
3 BooksComputers as components: Principles of Embedded Computing System Design, Wayne Wolf, Morgan Kaufman Publication, 2000ARM System Developer’s Guide: Designing and Optimizing System Software, Andrew N. Sloss, Dominic Symes, Chris Wright, , Morgan Kaufman Publication, 2004.Design with PIC Microcontrollers, John B. Peatman, Pearson Education Asia, 2002The Design of Small-Scale embedded systems, Tim Wilmshurst, Palgrave2003Embedded System Design, Marwedel, Peter, Kluwer Publishers,
4 DefinitionEmbedded system: any device that includes a computer but is not itself a general-purpose computer.Hardware and Software - part of some larger systems and expected to function without human interventionRespond, monitor, control external environment using sensors and actuatorsTypically, a embedded system will be targeted for a specific purpose and need to interact with external environments. This is the key distinguishing feature. Although some of the embedded systems can require some degree of general purpose functionality.
5 Embedding a computer Simplest model output analog input analog CPU mem This provides a very abstract, simplified view of the embedded systems. However, interfacing with the analog outside world is a critical component.memEmbedded computer
6 Examples Personal digital assistant (PDA). Printer. Cell phone. Automobile: engine, brakes, dash, etc.Television.Household appliances.Surveillance Systems.
8 Product: Motorola i1000plus iDEN Multi-Service Digital Phone Product: Motorola i1000plus iDEN Multi-Service Digital Phone. Microprocessor: Motorola 32-bit MCORE.
9 Application examplesSimple control: front panel of microwave oven, etc.Camera: Canon EOS 3 has three microprocessors.32-bit RISC CPU runs auto-focusAnalog TV: channel selection, etc.Digital TV: Decompression, Descrambling, etc.
10 Automotive embedded systems 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.
12 Characteristics of embedded systems Sophisticated functionality.Real-time operation (always?).Low manufacturing cost.Application dependent Processor (?)Restricted MemoryLow power.Power consumption is critical in battery-powered devices.Excessive power consumption increases system cost even in wall-powered devices.Manufacturing cost has different components. Non-recurring Engineering cost for design and development; cost of production and marketing each unit; best technology choice will depend on the number of units we plan to produce.
13 Manufacturing Cost Manufacturing cost has different components. Non-recurring Engineering cost for design and development;cost of production and marketing each unit;Best technology choice will depend on the number of units we plan to produce
14 Real-time operation Must finish operations by deadlines. Hard real time: missing deadline causes failure.Soft real time: missing deadline results in degraded performance.Many systems are multi-rate: must handle operations at widely varying rates.Operating Systems handle these components
15 Application dependent requirements Fault-toleranceContinue operation despite hardware or software faultsSafeSystems to avoid physical or economic damage to person or property
16 More Features Dedicated systems Predefined functionality – accordingly hardware and software designedProgrammability rarely used during lifetime of the systemReal-time, fault-tolerant, safe
25 Product: Sony Aibo ERS-110 Robotic Dog Product: Sony Aibo ERS-110 Robotic Dog. Microprocessor: 64-bit MIPS RISC.
26 Types of Embedded System Similar to General ComputingPDA, Video games, Set-top boxes, automatic teller machineControl SystemsFeed-back control of real time systemsVehicle engines, flight control, nuclear reactorsSignal ProcessingRadar, Sonar, DVD playersCommunication and NetworkingCellular phones, Internet appliances
27 Nature of System Functions Control lawsSequencing LogicSignal ProcessingApplication Specific InterfacingFault Response
30 Higher Degree of Integration Hardware EvolutionSystems-on-ChipApplication Specific ProcessorsDSPGeneral Purpose Microprocessors & Micro-controllersFaster Clock RateHigher Degree of Integration
31 Software Programs must be logically and temporally correct Must deal with inherent physical concurrencyReactive systemsReliability and fault-tolerance are critical issuesApplication Specific and single purpose
32 Multi-Tasking and Concurrency Embedded systems need to deal with several inputs and outputs and multiple events occurring independently.Separating tasks simplifies programming, but requires somehow switching back and forth among different tasks (multi-tasking).Concurrency is the appearance of simultaneous execution of multiple tasks.
34 Challenges in embedded system design How much hardware do we need?What is word size of the CPU? Size of Memory?How do we meet our deadlines?Faster hardware or cleverer software?How do we minimize power?Turn off unnecessary logic? Reduce memory accesses?
36 Design goals Performance. Functionality and user interface. Overall speed, deadlines.Functionality and user interface.Manufacturing cost.Power consumption.Other requirements (physical size, etc.)
37 Functional vs. non-functional requirements output as a function of input.Non-functional requirements:time required to compute output;size, weight, etc.;power consumption;reliability;etc.
38 Design & Development Process requirementsspecificationarchitecturecomponentdesignsystemintegration
39 Top-down vs. bottom-up Top-down design: Bottom-up design: start from most abstract description;work to most detailed.Bottom-up design:work from small components to big system.Real design uses both techniques.
40 Stepwise refinement At each level of abstraction, we must: analyze the design to determine characteristics of the current state of the design;refine the design to add detail.
41 Concluding Remarks 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.