Embedded Systems Microcontrollers & Embedded Processors An Overview

1. “In the name of God” Scientific Group of CSE Presents : Embedded SystemsMicrocontrollers & Embedded ProcessorsAn Overview By: Ramtin Raji Kermani Junior student of Computer Hardware Eng. Spring 2005 Department of Computer Sciences & Engineering, Shiraz University

2. Embedded Systems • What is an Embedded System? • Where are Embedded Systems used? • Typical Embedded Systems Hardware • Embedded OS and Software • Microcontrollers • The 8051 Microcontroller • A simple project using AT89C51 • References Department of Computer Sciences & Engineering, Shiraz University

3. 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) Department of Computer Sciences & Engineering, Shiraz University

4. What is and Embedded System? Department of Computer Sciences & Engineering, Shiraz University

5. 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 Department of Computer Sciences & Engineering, Shiraz University

6. 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. Department of Computer Sciences & Engineering, Shiraz University

7. ES Types & Characteristics • Types of Processing unit: • Hardwired logic • Programmable units • ES Characteristics: • Efficiently • Cost effective • Power efficiently • Real-time • Predictability Department of Computer Sciences & Engineering, Shiraz University

8. ES: History and Solutions • A very little history: ;) • The first Embedded System: Apollo Guidance Computer. • Embedded Systems Solutions: • Microcontrollers • Embedded Processors • Digital Signal processors Department of Computer Sciences & Engineering, Shiraz University

9. Where are Embedded Systems used? Department of Computer Sciences & Engineering, Shiraz University

10. 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) Department of Computer Sciences & Engineering, Shiraz University

11. 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 Department of Computer Sciences & Engineering, Shiraz University

12. 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 Department of Computer Sciences & Engineering, Shiraz University

13. 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) Department of Computer Sciences & Engineering, Shiraz University

14. 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 Department of Computer Sciences & Engineering, Shiraz University

15. What is a Microcontroller? • A microcontroller is an entire computer manufactured on a single chip. • They have a high concentration of on-chip facilities such as serial ports, parallel input/output ports, timers, counters, interrupt control, analog-to-digital converters, random access memory, read only memory, etc. Department of Computer Sciences & Engineering, Shiraz University

16. The 8051 Microcontroller: • The 8051 is the first microcontroller of the MCS-51 family introduced by Intel Corporation at the end of the 1970’s. • The 8051 family characteristics: • 4K Bytes ROM • 128 Bytes RAM • two timer/counters (16 bit) • A serial port • 4 general purpose parallel input/output port • Interrupt controller The 8051 can address 64K of external data memory and 64K of External program memory. Department of Computer Sciences & Engineering, Shiraz University

17. Microcontroller 8051 internal Architecture Department of Computer Sciences & Engineering, Shiraz University

18. 8051 pin description • 8051 other family members: • 8751 (has EPROM) • 8951 (has EEPROM) Department of Computer Sciences & Engineering, Shiraz University

19. A simple project using AT89C51 • Here we’ve designed, built and programmed a digital BCD counter that counts from 0 to 9 on a 7Segment display. • We use register A as Accumulator, in each delayed cycle the accumulator increments by one and result is showed on the 7segment display. Department of Computer Sciences & Engineering, Shiraz University

20. A simple project using AT89C51 Department of Computer Sciences & Engineering, Shiraz University

21. 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 • Books: • The 8051 Microcontroller and Embedded Systems: Mazidi, M.A. • Microprocessors: Uffenbeck, john • 201 مدار عملی با میکروکنترولر 8051، ف. خاکپور، انتشارات صفار Department of Computer Sciences & Engineering, Shiraz University

22. At the End … • Thanks for your Attention … ;) Ramtin Raji Kermani Spring 2005 Department of Computer Sciences & Engineering, Shiraz University