51778021 Embedded Systems

7/30/2019 51778021 Embedded Systems

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NWIET, DHUDIKE. MOGA

Embedded SystemsMicrocontrollers & Embedded Processors

An Overview

By: AVTAR SINGH MALHI

Uni. Roll No:90510414053

“In the name of God” Scientific Group of ECE Presents :




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




What is and Embedded System?

A specialized computer system that is part of alarger system or machine. Typically, anembedded system is housed on a single

microprocessor board with the programs storedin ROM. Virtually all appliances that have adigital interface -- watches, microwaves, VCRs,cars -- utilize embedded systems. Someembedded systems include an operatingsystem, but many are so specialized that theentire logic can be implemented as a singleprogram. (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

Types of Processing unit:

Hardwired logic

Programmable units

ES Characteristics:

Efficiently

Cost effective

Power efficiently

Real-time

Predictability




ES: History and Solutions

A very little history: ;) The first Embedded System: Apollo Guidance Computer.

Embedded Systems Solutions: Microcontrollers

Embedded Processors

Digital Signal processors









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




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




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.




The 8051 Microcontroller:

The 8051 is the first microcontroller of the MCS-51 family introduced by IntelCorporation 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 Externalprogram memory.




Microcontroller 8051 internal Architecture




8051 pin description

8051 other family members:

8751 (has EPROM) 8951 (has EEPROM)





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.








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



http://citeseer.nj.nec.com/497408.html






51778021 Embedded Systems

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