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May 16, 2005 Department of Computer Sciences & Engineering, Shiraz University
Embedded SystemsMicrocontrollers & Embedded Processors
An Overview
By: Ramtin Raji Kermani
Junior student of Computer Hardware Eng.
Spring 2005
“In the name of God”
Scientific Group of CSE Presents :
Department of Computer Sciences & Engineering, Shiraz University
May 16, 2005
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
May 16, 2005
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
May 16, 2005
What is and Embedded System?
Department of Computer Sciences & Engineering, Shiraz University
May 16, 2005
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
May 16, 2005
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
May 16, 2005
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
May 16, 2005
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
May 16, 2005
Where are Embedded Systems used?
Department of Computer Sciences & Engineering, Shiraz University
May 16, 2005
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
May 16, 2005
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
May 16, 2005
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
May 16, 2005
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
May 16, 2005
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
May 16, 2005
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
May 16, 2005
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
May 16, 2005
Microcontroller 8051 internal Architecture
Department of Computer Sciences & Engineering, Shiraz University
May 16, 2005
8051 pin description
8051 other family members: 8751 (has EPROM) 8951 (has EEPROM)
Department of Computer Sciences & Engineering, Shiraz University
May 16, 2005
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
May 16, 2005
A simple project using AT89C51
Department of Computer Sciences & Engineering, Shiraz University
May 16, 2005
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 میکروکنترولر 201 با عملی . 8051مدار انتشارات خاکپور، ف ،
صفار
Department of Computer Sciences & Engineering, Shiraz University
May 16, 2005
At the End …
Thanks for your Attention … ;)
Ramtin Raji Kermani
Spring 2005