What is embedded system?
An Embedded
system is a combination of computer hardware such as processors,
memory and logic devices, software and other additional
electromechanical, electrical, electronic parts, designed to
perform a specific function within a given time frame. In other
words, it is a specialized program residing on a microchip used to
control devices such as automobiles, home and office appliances,
handheld units and all kind of devices in combination with
operating system & specific application functions.Today we are in
convergence world and embedded solutions are used everywhere in
almost all digital electronic applications.
History
of practical Embedded System dates back
to 1968, the
Volkswagen 1600 used a microprocessor in its fuel injection
system, launching the first
embedded system
in the automotive industry.

How different embedded systems and components relate to each
other?
|
Component |
What they do? |
How they are made? |
|
|
Microprocessor
|
controller
and heart of the system “Microcontrollers” |
Processor Technologies
-
General-purpose processors (GPP)
-
Application-Specific Processors
-
Single-purpose Processors, DSPs
IC Technologies
-
Pure
memory ICs - ROM, RAM, NVRAM, Flash
-
FLD/PLD/PIC/PLC,
CPLD, FPGA
-
Semi-custom (ASIC)
-
Full-custom (VLSI)
Vendor specific Cores
(ARM, TI..) |
|
|
Memory |
stores
program code or data and enable read/write -EPROM, EEPROM,
RAM, Flash
|
|
|
Logic devices |
provide
specific functions like device-to-device interfacing, data
communication, signal processing, data display, timing and
control operations
|
Devising an
Embedded System application involves use of available general
purpose Microprocessors or special purpose processors like
Microcontrollers, DSP, ASICs and FPGA along with software tools to
achieve a specific function. The design process uses assembly
programming or other high level languages such as C, C++ along
with specific operating systems or real-time OS (RTOS) or
advanced system design software tools.
In practice,
all these components are combined and designed accordingly. That
is, applications processors, memory and logic devices are
generally combined using Processor or IC technologies depending
upon application. Based on performance and flexibility, embedded
products assume different names as below.
Fixed
Logic Devices (FLD)
Programmable Logic Devices(PLD):
-
Simple PLD – FPD, PLA, PAL, PIC, PLC, Microcontrollers
-
Versatile,
Standard, flexible logic features, speed, and voltage
characteristics, quick to develop, simulate and design; based
on re-writable memory technology
-
Also called
Field programmable device (FPD), Programmable logic array (PLA),
Programmable array logic (PAL)
Complex PLD – CPLD(Complex programmable logic devices)
-
Lower logic
density (say up to 10000 gates)
-
Very
predictable timing characteristics; ideal for critical control
applications
-
Uses low
power, less expensive, battery-operated
-
Used in
portable applications such as mobile phones and digital
handheld devices
-
Also called
EPLD, SuperPAL, MegaPAL
FPGA
(Field programmable gate arrays)
-
High logic
density (say 8 million gates) and high performance
-
Uses
built-in hardwired processors, more memory, clock management
systems
-
Supports
very fast device-to-device signaling technologies
-
Used in a
variety of applications like data processing, storage,
instrumentation, telecommunications and digital signal
processing.
FPGA is best
suited as communication processors for multi channel and
parallel processing (like OFDM wireless processors) and often
act as hardwired coprocessor.
DSP standard
architecture suited for single channel real time processing
VLSI Design
is all about hardware-oriented design of the internal Digital
circuitry of a chip and write a hardware description code for
the same using advanced tools like MATLAB, 20Sim and VHDL/Verilog
kind of programming concepts.

Embedded
design and software tools
Generic Operating systems
Windows,
Windows CE, Unix, Linux, Mac and so on.
Real-time operating system (RTOS)
Specialized
control software that's often used in embedded computing
applications that have tight memory resources and stringent
performance requirements relating to immediate response times,
high availability and accurate self-monitoring capabilities.
-
VxWORKS -
This RTOS is from Wind River Systems and used for complex
real-time and embedded applications on a wide variety of
target processors.
-
QNX - QNX 4
is developed by QNX Software Systems. It is a fast, scalable
RTOS and can handle all different functions like memory
management, process creation and timing control.
-
Lynx -
Lynx is a powerful and proprietary RTOS based on UNIX.
-
pSOS - pSOS
is a special kind of multitasking RTOS specially suited for
embedded microprocessors.
-
And there
are many more..
Software Tools
Assembly
languages, C/C++, VB, compilers, Java, Java Virtual Machines,
J2ME, BREW Platforms, VHDL, Verilog Programming Languages,
Compilers, Software Platforms, Design Tools, libraries/APIs,
test/verification tools, Simulation packages.

Embedded technologies
landscape
Generic diagram
below provides overview of different embedded system design
concepts- how the technology is progressing from
microelectronics to future of nano technology.
Hardware design
view:
1.gif)
Click on the image
to view larger
Software and
application view:


Embedded processors in mobile and wireless technologies
With wireless
evolution all the handheld mobile devices uses rich variety of
embedded processors. A mobile for for instance is a combination
of many embedded solutions.
Design of embedded solutions for
mobile applications needs good understanding of underlying
wireless technologies and application interfaces


Embedded Solution Trends
(An adapted listing from industry
sources)
|
Industrial Automation
Remote monitoring
& Industrial control
Industrial automation using Firewire (1394)
Controller Area Network (CAN) applications
Automatic tracking systems using wireless
Automobile Electronics
Cellular networks
for navigation/ telematics
Using Bluetooth for Smart Car applications
Using WLAN for automobile rear view systems
VLSI & Semiconductor
VLSI
implementation of OFDM techniques
ASIC chip-set design for high-end networks
Integrating IP with fibre optic/10GB Ethernet
iSCSI (Internet SCSI) applications
Digital transmission content protection
Aviation Electronics
Applying embedded
solutions for aircraft safety
Microcontrollers for airborne systems
Intelligent In-flight entertainment applications
Medical Electronics
Integrating
medical devices and instruments
|
Mobile Devices and
Applications
Innovating Java
applications in mobile phones
Mobile network solutions for 3G/UMTS//CDMA
Mobile IP platforms- BREW, JAVA/J2ME, .NET
Location based services, GPS integration
Messaging and push-to-talk services
Multimedia
Customized DSP solutions for
multimedia
Integrating real time & non-real time I/O devices
Speech codec applications - MP3, AAC
Video codec applications MPEG-4, FGS, H.264
Digital watermarking applications
Computing Platforms &
Peripherals
Software products
testing
High performance device drivers
Softwear: Wearable computers
Microcontroller Simulators, debuggers
Cross Compilers for PLC programming
Consumer Electronics
System-on-Chip (SoC)
Software Defined Radio (SDR)
Residential Gateway (RG)
Home networking & Home Automation
Multimedia Home Platform (MHP)
Integrating
Cable/DSL, Firewire, USB, BT, Wi-fi
Digital TV & Interactive TV Applications
AV controller digital interface |

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