2. An Embedded system is a combination of computer
hardware and software. As with any electronic system,
this system requires a hardware platform and that is
built with a microprocessor or microcontroller.
The Embedded system hardware includes elements
like user interface, Input/output interfaces, display
and memory, etc.
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3. Embedded System
On an embedded system, resources -- memory and CPU power -
- are limited. By comparison, with desktop systems, it is
commonly assumed that they have no limits.
Embedded systems are commonly real-time.
The number of operating systems in use on desktop computers is
quite small. There are numerous options for embedded systems,
including "bare metal" (i.e., no operating system at all).
To the first approximation, the hardware of all PCs is identical. By
comparison, every embedded system is different, so
programming close to the hardware is more common.
In many ways, programming an embedded system is not too dissimilar
to coding for a desktop computer, but there are some key differences:
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4. Embedded systems can be classified into different types based on performance,
functional requirements and performance of the microcontroller.
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5. This type of embedded system may be component of large system in
which it is embedded, such a component called embedded system.
The connection can be any wired or wireless.
This type of embedded system is the fastest growing area in embedded
system applications.
The embedded web server is a type of system wherein all embedded
devices are connected to a web server and accessed and controlled by a
web browser.
Example: Auto mobiles, vehicle model and controller design.
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6. Components of large systems
Assembly languages
Sequential systems implementation languages — e.g. RTL/2, Coral 66,
Jovial, C.
Normally require operating system support.
High-level concurrent languages. Impetus from the software crisis. e.g.
Ada, Chill, Modula-2, Mesa, Java.
We will consider:
Java/Real-Time Java
C and Real-Time POSIX
Ada 95
Also Modula-1 for device driving
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8. Stand alone embedded systems do not require a host system
like a computer, it works by itself.
It takes the input from the input ports either analog or digital
and processes, calculates and converts the data and gives the
resulting data through the connected device-Which either
controls, drives and displays the connected devices.
Examples for the stand alone embedded systems are mp3
players, digital cameras, video game consoles, microwave ovens
and temperature measurement systems.
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9. Languages used in:
Java :
It provides a technique known as “native methods",
where c/c++ or assembly code can be called directly
from java to manipulate the hardware registers and
memory directly using pointers.
This can sometimes be useful in embedded
systems.
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10. These types of embedded systems are related to a network
to access the resources.
The connected network can be LAN, WAN or the internet.
The connection can be any wired or wireless.
This type of embedded system is the fastest growing area in
embedded system applications.
Example for the LAN networked embedded system is a home
security system wherein all sensors are connected and run
on the protocol TCP/IP
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11. Languages used in:
nesC
Networked embedded system is a sensor network, which consists of
(potentially) thousands of tiny, low-power 'motes,' each of which
execute concurrent, reactive programs that must operate with severe
memory and power constraints.
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12. Mobile embedded systems are used in portable
embedded devices like cell phones, mobiles, digital
cameras, mp3 players and personal digital assistants, etc.
The basic limitation of these devices is the other
resources and limitation of memory.
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13. Smart-phones contain several embedded systems, like
the modem core and the single-chip WiFi+BT+GPS
solutions.
Smart phones usually have custom-purpose hardware and
software for a specific task (i.e. making phone calls and
accessing the cellular data network) which technically makes
them embedded systems.
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14. These types of embedded systems are designed with a
single 8 or 16 bit microcontroller, that may even be activated
by a battery.
For developing embedded software for small scale
embedded systems, the main programming tools are an
editor, assembler, cross assembler and integrated
development environment (IDE).
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15. Language Used In Small- Scale Embedded Systems:
µITRON
ITRON is a Japanese open standard for a real-time operating
system (RTOS).
This project aims to standardize the RTOS and related specifications
for embedded systems, particularly small-scale embedded systems.
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16. These types of embedded systems design with a single or 16
or 32 bit microcontroller, RISCs or DSPs.
These types of embedded systems have both hardware and
software complexities.
For developing embedded software for medium scale
embedded systems, the main programming tools are C, C++,
JAVA, Visual C++, RTOS, debugger, source code
engineering tool, simulator and IDE.
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17. Examples:
Computer networking systems for example : routers, front end
processor in a server ,etc.
Entertainment systems such as video game and a music systems.
Signal tracking systems such as automatic signal tracking and target
tracking.
Communication systems such as mobile communication SIM card,
cellular phone, a cable TV terminal, etc.
Image filtering, image processing, pattern recognizer, speech
processing and video processing.
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18. These types of embedded systems have enormous hardware
and software complexities, that may need ASIPs, IPs, PLAs,
scalable or configurable processors.
They are used for cutting-edge applications that need
hardware and software Co-design and components which have
to assemble in the final system.
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19. Examples:
Multimedia processing systems.
Wireless LAN and convergent technology devices.
Interface and networking systems using high speed and ultra
high speed and large band width.
System for space life boats(under development by NASA).
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20. Reliability: R(t) = probability of system working
correctly provided that is was working at t=0
Maintainability: M(d) = probability of system working
correctly d time units after error occurred.
Availability: probability of system working at time t
Safety: no harm to be caused
Security: confidential and authentic communication
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21. Efficiency:
Energy efficient
Code-size efficient (especially for systems on a chip)
Run-time efficient
Weight efficient
Cost efficient
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22. Many ES must meet real-time constraints:
A real-time system must react to stimuli from the controlled
object (or the operator) within the time interval dictated by the
environment.
For real-time systems, right answers arriving too late (or even
too early) are wrong.
All other time-constraints are called soft.
A guaranteed system response has to be explained without
statistical arguments.
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23. Frequently connected to physical environment through sensors
and actuators
Hybrid systems (analog + digital parts).
Behavior depends on input and current state.
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24. Embedded systems are used in different
applications like
automobiles
telecommunications
smart cards
missiles
satellites
computer networking
digital consumer electronics.
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25. Embedded systems are application-specific computers that
interact with the physical world.
Each has a diverse set of tasks to perform, and although a very
flexible language might be able to handle all of them, instead a
variety of problem-domain-specific languages have evolved that
are easier to write, analyze, and compile.
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