Embedded Systems Microcontrollers & Embedded Processors An Overview
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Embedded Systems Microcontrollers & Embedded Processors An Overview. Embedded Systems. What is an Embedded System? Where are Embedded Systems used? Typical Embedded Systems Hardware Embedded OS and Software References. What is and Embedded System?.
Embedded Systems Microcontrollers & Embedded Processors An Overview
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Embedded SystemsMicrocontrollers & Embedded ProcessorsAn Overview
Embedded Systems • What is an Embedded System? • Where are Embedded Systems used? • Typical Embedded Systems Hardware • Embedded OS and Software • References
What is and Embedded System? A specialized computer system that is part of a larger system or machine. Typically, an embedded system is housed on a single microprocessor board with the programs stored in ROM. Virtually all appliances that have a digital interface -- watches, microwaves, VCRs, cars -- utilize embedded systems. Some embedded systems include an operating system, but many are so specialized that the entire logic can be implemented as a single program. (Definition from wikipedia.com)
ES, Other definitions • A special purpose computer built into a larger device. • Special purpose: • - Embedded systems have a (more or less) well-defined purpose • - Contrast with: general purpose computers (PCs etc) • - Both hardware and software is tailored to application(s), which are well defined • - However, re-programmability is a requirement • Built into a larger device: • ESs are (usually) part of a larger device, augmenting its capabilities
ES, Other definitions • Any device that includes a programmable computer but is not itself a general-purpose computer. • Anything that uses a computer but does not look like one. • The microprocessor in an embedded system is like an electric motor in a washing machine.
ES Types & Characteristics • ES Characteristics: • Efficiently • Cost effective • Power efficiently • Real-time • Predictability
Where are Embedded Systems used? • Signal processing systems • Real-time video, DVD players, Medical equipment. • Distributed control • Network routers, switches, firewalls, mass transit systems, Elevators • “Small” systems • Mobile phones, pagers, 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)
Typical Embedded Systems Hardware • Commercial off-the-shelf components (COTS) • e.g. wireless radios, sensors, I/O devices • Cheap • Application-Specific ICs (ASICs) • ICs tailored to meet application needs • Good performance for their intended task(s) • Original ESs were ASICs only • Domain-specific processors • DSPs • Microcontrollers • Microprocessors • General Purpose Processors
ES: Solutions • Embedded Systems Solutions: • Microcontrollers • Embedded Processors • Digital Signal processors
New trends in ES HW • Systems-on-chip • Usual (or desired) specs: • 32-bit RISC CPU • Built-in interfaces to RAM and ROM • Built-in DMA, interrupt and timing controllers • Built-in interfaces to disk or flash memory • Built-in Ethernet/802.11 interfaces • Built-in LCD/CRT interfaces • New SOCs appearing almost every week! • Examples • Intel StrongARM SA-1110 • Motorola PowerPC MPC823e • NEC VR4181 • Many, many more
Embedded OS and Software • Principal role: ‘Not transformation of data but interaction with physical world’ • Acquires properties of physical world • Takes time • Consumes power • Does not terminate (unless it fails)
Embedded Operating Systems: • Office-style OSes • PalmOS • WindowsCE • RTOSes • VxWorks • QNX • Linux • Linux is already ubiquitous • Hundreds of different devices are using it • http://www.linuxdevices.com/articles/AT4936596231.html • Numerous commercial + open source products • Mobile OS • Symbian • Others • TinyOS
References • Web References: • www.google.com • http://www.embedded.com • http://www.wikipedia.org/wiki/Embedded_system • http://www.linuxdevices.com • Mani Srivastava’s EE202A class • http://nesl.ee.ucla.edu/courses/ee202a/2002f • Edward Lee, “Embedded Software” • http://citeseer.nj.nec.com/497408.html • Microprocessors: Uffenbeck, john • Books: • The 8051 Microcontroller and Embedded Systems: Mazidi, M.A. • 201 مدار عملی با میکروکنترولر 8051، ف. خاکپور، انتشارات صفار