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22 nd October 2008. Embedded System Design. By Santosh N.Gudge. Definition. Embedded System : Any Device that includes a computer but is not itself a general-purpose computer.
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22nd October 2008 Embedded System Design By Santosh N.Gudge
Definition • Embedded 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 intervention. • Respond, Monitor, control external environment using sensors and Actuators.
Examples • Personal Digital assistant(PDA). • Printer. • Cell Phone. • Automobile: Engine, brakes, Dash, etc. • Television. • Household appliances. • Surveillance System.
Automotive embedded Systems • Today’s high-end automobile may have 100 microprocessors. • 4-bit Microcontrollers run dashboard devices. • 16/32-bit microprocessor controls engine.
Characteristics of embedded Systems • Sophisticated functionality. • Low manufacturing cost. • Application dependent processor ( ?) • Restricted Memory • Low power . **Power consumption is critical in battery-powered devices.
Types of Embedded System • Similar to General Computing *PDA, Set-top boxes, video games etc • Control Systems *flight control, Nuclear reactors • Signal processing *Radar, Sonar, DVD players • Communication and Networking *Cellular phones, Internet appliances.
Challenges in embedded System design • How much hardware do you 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?
Design goals • Performance *overall speed, deadlines. • Functionality and user interface. • Manufacturing cost. • Power consumption. • Other requirements(physical size, etc.)
Functional vs. non-functional requirements • Functional requirements: *output as a function of input. • Non-functional requirements: >time required to compute output; >size, weight , etc; >power consumption; >reliability; Etc.
Top-down vs bottom-up • Top-down design >start from most abstract description; >work to most detailed. • Bottom-up design: >work from small components to big system.
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.
References • http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?tp=&arnumber=4141246&isnumber=4141231 • http://www.ece.cmu.edu/~koopman/iccd96/iccd96.html