May 16, 2005 Department of Computer Sciences & Engineering, Shiraz University Embedded Systems Microcontrollers & 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/ 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  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, 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:      Mani Srivastava’s EE202A class  Edward Lee, “Embedded Software” 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 May 16, 2005 At the End … Thanks for your Attention … ;) Ramtin Raji Kermani Spring 2005