Embedded Systems Microcontrollers Embedded Processors An Overview Embedded

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? 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)

What is and Embedded System?

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, MP 3 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)

CELL PHONE –Block Diagram

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 Strong. ARM SA-1110 Motorola Power. PC MPC 823 e NEC VR 4181 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 ◦ Palm. OS ◦ Windows. CE � RTOSes ◦ Vx. Works ◦ QNX � Linux ◦ Linux is already ubiquitous � Hundreds of different devices are using it � http: //www. linuxdevices. com/articles/AT 4936596231. html ◦ Numerous commercial + open source products � Mobile OS ◦ Symbian � Others ◦ Tiny. OS

References � Web References: ◦ ◦ ◦ www. google. com http: //www. embedded. com http: //www. wikipedia. org/wiki/Embedded_system http: //www. linuxdevices. com Mani Srivastava’s EE 202 A class � http: //nesl. ee. ucla. edu/courses/ee 202 a/2002 f ◦ Edward Lee, “Embedded Software” � http: //citeseer. nj. nec. com/497408. html ◦ � Microprocessors: Uffenbeck, john Books: ◦ The 8051 Microcontroller and Embedded Systems: Mazidi, M. A. ◦ ﺍﻧﺘﺸﺎﺭﺍﺕ ﺻﻔﺎﺭ ، ﺧﺎکپﻮﺭ. ﻑ ،8051 ﻣﺪﺍﺭ ﻋﻤﻠی ﺑﺎ ﻣیکﺮﻭکﻨﺘﺮﻭﻟﺮ 201