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 EMBEDDED SYSTEMS

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مُساهمةموضوع: EMBEDDED SYSTEMS   الثلاثاء 09 مارس 2010, 4:01 pm



Picture of the internals of a ADSL modem/router. A modern example of an embedded system. Labelled parts include a microprocessor (4), RAM (6), and flash memory (7).





An embedded system is a computer system designed to perform one or a few dedicated functions[1][2] often with real-time computing constraints. It is embedded as part of a complete device often including hardware and mechanical parts. By contrast, a general-purpose computer, such as a personal computer
(PC), is designed to be flexible and to meet a wide range of end-user
needs. Embedded systems control many devices in common use today.[3]
Embedded systems are controlled by one or more main processing cores that is typically either a microcontroller or a digital signal processor (DSP).[4]
The key characteristic is however being dedicated to handle a
particular task, which may require very powerful processors. For
example, air traffic control systems may usefully be viewed as embedded, even though they involve mainframe computers
and dedicated regional and national networks between airports and radar
sites. (Each radar probably includes one or more embedded systems of
its own.)
Since the embedded system is dedicated to specific tasks, design
engineers can optimize it reducing the size and cost of the product and
increasing the reliability and performance. Some embedded systems are
mass-produced, benefiting from economies of scale.
Physically, embedded systems range from portable devices such as digital watches and MP3 players, to large stationary installations like traffic lights, factory controllers, or the systems controlling nuclear power plants. Complexity varies from low, with a single microcontroller chip, to very high with multiple units, peripherals and networks mounted inside a large chassis or enclosure.
In general, "embedded system" is not a strictly definable term, as
most systems have some element of extensibility or programmability. For
example, handheld computers
share some elements with embedded systems such as the operating systems
and microprocessors which power them, but they allow different
applications to be loaded and peripherals to be connected. Moreover,
even systems which don't expose programmability as a primary feature
generally need to support software updates. On a continuum from
"general purpose" to "embedded", large application systems will have
subcomponents at most points even if the system as a whole is "designed
to perform one or a few dedicated functions", and is thus appropriate
to call "embedded".//

[edit] Variety of embedded systems



PC Engines' ALIX.1C Mini-ITX embedded board with an x86 AMD Geode LX 800 together with Compact Flash, miniPCI and PCI slots, 22-pin IDE interface, audio, USB and 256MB RAM






An embedded RouterBoard 112 with U.FL-RSMA pigtail and R52 miniPCI Wi-Fi card widely used by wireless Internet service providers (WISPs) in the Czech Republic.





Embedded systems span all aspects of modern life and there are many examples of their use.
Telecommunications systems employ numerous embedded systems from telephone switches for the network to mobile phones at the end-user. Computer networking uses dedicated routers and network bridges to route data.
Consumer electronics include personal digital assistants (PDAs), mp3 players, mobile phones, videogame consoles, digital cameras, DVD players, GPS receivers, and printers. Many household appliances, such as microwave ovens, washing machines and dishwashers, are including embedded systems to provide flexibility, efficiency and features. Advanced HVAC systems use networked thermostats to more accurately and efficiently control temperature that can change by time of day and season. Home automation
uses wired- and wireless-networking that can be used to control lights,
climate, security, audio/visual, surveillance, etc., all of which use
embedded devices for sensing and controlling.
Transportation systems from flight to automobiles increasingly use embedded systems. New airplanes contain advanced avionics such as inertial guidance systems and GPS receivers that also have considerable safety requirements. Various electric motors — brushless DC motors, induction motors and DC motors — are using electric/electronic motor controllers. Automobiles, electric vehicles, and hybrid vehicles are increasingly using embedded systems to maximize efficiency and reduce pollution. Other automotive safety systems include anti-lock braking system (ABS), Electronic Stability Control (ESC/ESP), traction control (TCS) and automatic four-wheel drive.
Medical equipment is continuing to advance with more embedded systems for vital signs monitoring, electronic stethoscopes for amplifying sounds, and various medical imaging (PET, SPECT, CT, MRI) for non-invasive internal inspections.
In addition to commonly described embedded systems based on small computers, a new class of miniature wireless devices called motes are quickly gaining popularity as the field of wireless sensor networking rises. Wireless sensor networking, WSN,
makes use of miniaturization made possible by advanced IC design to
couple full wireless subsystems to sophisticated sensors, enabling
people and companies to measure a myriad of things in the physical
world and act on this information through IT monitoring and control
systems. These motes are completely self contained, and will typically
run off a battery source for many years before the batteries need to be
changed or charged.
[edit] History


In the earliest years of computers in the 1930–40s, computers were
sometimes dedicated to a single task, but were far too large and
expensive for most kinds of tasks performed by embedded computers of
today. Over time however, the concept of programmable controllers evolved from traditional electromechanical sequencers, via solid state devices, to the use of computer technology.
One of the first recognizably modern embedded systems was the Apollo Guidance Computer, developed by Charles Stark Draper
at the MIT Instrumentation Laboratory. At the project's inception, the
Apollo guidance computer was considered the riskiest item in the Apollo
project as it employed the then newly developed monolithic integrated
circuits to reduce the size and weight. An early mass-produced embedded
system was the Autonetics D-17 guidance computer for the Minuteman missile, released in 1961. It was built from transistor logic and had a hard disk
for main memory. When the Minuteman II went into production in 1966,
the D-17 was replaced with a new computer that was the first
high-volume use of integrated circuits. This program alone reduced
prices on quad nand gate ICs from $1000/each to $3/each, permitting their use in commercial products.
Since these early applications in the 1960s, embedded systems have
come down in price and there has been a dramatic rise in processing
power and functionality. The first microprocessor for example, the Intel 4004, was designed for calculators
and other small systems but still required many external memory and
support chips. In 1978 National Engineering Manufacturers Association
released a "standard" for programmable microcontrollers, including
almost any computer-based controllers, such as single board computers,
numerical, and event-based controllers.
As the cost of microprocessors and microcontrollers fell it became feasible to replace expensive knob-based analog components such as potentiometers and variable capacitors
with up/down buttons or knobs read out by a microprocessor even in some
consumer products. By the mid-1980s, most of the common previously
external system components had been integrated into the same chip as
the processor and this modern form of the microcontroller
allowed an even more widespread use, which by the end of the decade
were the norm rather than the exception for almost all electronics
devices.
The integration of microcontrollers has further increased the
applications for which embedded systems are used into areas where
traditionally a computer would not have been considered. A general
purpose and comparatively low-cost microcontroller may often be
programmed to fulfill the same role as a large number of separate
components. Although in this context an embedded system is usually more
complex than a traditional solution, most of the complexity is
contained within the microcontroller itself. Very few additional
components may be needed and most of the design effort is in the
software. The intangible nature of software makes it much easier to
prototype and test new revisions compared with the design and
construction of a new circuit not using an embedded processor.
[edit] Characteristics



Soekris net4801, an embedded system targeted at network applications.






  1. Embedded systems are designed to do some specific task, rather than
    be a general-purpose computer for multiple tasks. Some also have real-time
    performance constraints that must be met, for reasons such as safety
    and usability; others may have low or no performance requirements,
    allowing the system hardware to be simplified to reduce costs.
  2. Embedded systems are not always standalone devices. Many embedded
    systems consist of small, computerized parts within a larger device
    that serves a more general purpose. For example, the Gibson Robot Guitar features an embedded system for tuning the strings, but the overall purpose of the Robot Guitar is, of course, to play music.[5] Similarly, an embedded system in an automobile provides a specific function as a subsystem of the car itself.
  3. The program instructions written for embedded systems are referred to as firmware, and are stored in read-only memory or Flash memory chips. They run with limited computer hardware resources: little memory, small or non-existent keyboard and/or screen.

[edit] User interface



Embedded system text user interface using MicroVGA





Embedded systems range from no user interface at all — dedicated only to one task — to complex graphical user interfaces that resemble modern computer desktop operating systems. Simple embedded devices use buttons, LEDs, graphic or character LCDs (for example popular HD44780 LCD) with a simple menu system.
A more sophisticated devices use graphical screen with touch
sensing or screen-edge buttons provide flexibility while minimizing
space used: the meaning of the buttons can change with the screen, and
selection involves the natural behavior of pointing at what's desired. Handheld systems often have a screen with a "joystick button" for a pointing device.
Some systems provide user interface remotely with the help of serial (e.g. RS-232, USB, I²C, etc) or network (e.g. Ethernet)
connection. In spite of installed client software and cables are needed
this approach usually gives a lot of advantages: extends the
capabilities of embedded system, avoids the cost of a display,
simplifies BSP, allows to build rich user interface on PC. One of the well established model in this direction is the combination of embedded web server running on embedded device and user interface in web browser on PC (typical for IP cameras and network routers).
[edit] Processors in embedded systems


Embedded processors can be broken into two broad categories:
ordinary microprocessors (μP) and microcontrollers (μC), which have
many more peripherals on chip, reducing cost and size. Contrasting to
the personal computer and server markets, a fairly large number of
basic CPU architectures are used; there are Von Neumann as well as various degrees of Harvard architectures, RISC as well as non-RISC and VLIW; word lengths vary from 4-bit to 64-bits and beyond (mainly in DSP
processors) although the most typical remain 8/16-bit. Most
architectures come in a large number of different variants and shapes,
many of which are also manufactured by several different companies.
A long but still not exhaustive list of common architectures are: 65816, 65C02, 68HC08, 68HC11, 68k, 8051, ARM, AVR, AVR32, Blackfin, C167, Coldfire, COP8, Cortus APS3, eZ8, eZ80, FR-V, H8, HT48, M16C, M32C, MIPS, MSP430, PIC, PowerPC, R8C, SHARC, ST6, SuperH, TLCS-47, TLCS-870, TLCS-900, Tricore, V850, x86, XE8000, Z80, AsAP etc.
[edit] Ready made computer boards


PC/104 and PC/104+ are examples of standards for ready made computer boards intended for small, low-volume embedded and ruggedized systems, mostly x86-based. These often use DOS, Linux, NetBSD, or an embedded real-time operating system such as MicroC/OS-II, QNX or VxWorks. Sometimes these boards use non-x86 processors.
In certain applications, where small size or power efficiency are
not primary concerns, the components used may be compatible with those
used in general purpose x86 personal computers. Boards such as the VIA EPIA
range help to bridge the gap by being PC-compatible but highly
integrated, physically smaller or have other attributes making them
attractive to embedded engineers. The advantage of this approach is
that low-cost commodity components may be used along with the same
software development tools used for general software development.
Systems built in this way are still regarded as embedded since they are
integrated into larger devices and fulfill a single role. Examples of
devices that may adopt this approach are ATMs and arcade machines, which contain code specific to the application.
However, most ready-made embedded systems boards are not PC-centered and do not use the ISA or PCI busses. When a System-on-a-chip
processor is involved, there may be little benefit to having a
standarized bus connecting discrete compontents, and the environment
for both hardware and software tools may be very different.
One common design style uses a small system module, perhaps the size of a business card, holding high density BGA chips such as an ARM-based System-on-a-chip processor and peripherals, external flash memory for storage, and DRAM
for runtime memory. The module vendor will usually provide boot
software and make sure there is a selection of operating systems,
usually including Linux
and some real time choices. These modules can be manufactured in high
volume, by organizations familiar with their specialized testing
issues, and combined with much lower volume custom mainboards with
application-specific external peripherals. Gumstix product lines are a Linux-centric example of this model.
[edit] ASIC and FPGA solutions


A common configuration for very-high-volume embedded systems is the system on a chip
(SoC) which contains a complete system consisting of multiple
processors, multipliers, caches and interfaces on a single chip. SoCs
can be implemented as an application-specific integrated circuit (ASIC) or using a field-programmable gate array (FPGA).
[edit] Peripherals


Embedded Systems talk with the outside world via peripherals, such as:

  • Serial Communication Interfaces (SCI): RS-232, RS-422, RS-485 etc
  • Synchronous Serial Communication Interface: I2C, SPI, SSC and ESSI (Enhanced Synchronous Serial Interface)
  • Universal Serial Bus (USB)
  • Multi Media Cards (SD Cards, Compact Flash etc)
  • Networks: Ethernet, Controller Area Network, LonWorks, etc
  • Timers: PLL(s), Capture/Compare and Time Processing Units
  • Discrete IO: aka General Purpose Input/Output (GPIO)
  • Analog to Digital/Digital to Analog (ADC/DAC)
  • Debugging: JTAG, ISP, ICSP, BDM Port, BITP DP9 port ...

[edit] Tools


As for other software, embedded system designers use compilers, assemblers, and debuggers to develop embedded system software. However, they may also use some more specific tools:

  • In circuit debuggers or emulators (see next section).
  • Utilities to add a checksum or CRC to a program, so the embedded system can check if the program is valid.
  • For systems using digital signal processing, developers may use a math workbench such as Scilab / Scicos, MATLAB / Simulink, EICASLAB, MathCad, or Mathematica
    to simulate the mathematics. They might also use libraries for both the
    host and target which eliminates developing DSP routines as done in DSPnano RTOS and Unison Operating System.
  • Custom compilers and linkers may be used to improve optimisation for the particular hardware.
  • An embedded system may have its own special language or design tool, or add enhancements to an existing language such as Forth or Basic.
  • Another alternative is to add a real-time operating system or embedded operating system, which may have DSP capabilities like DSPnano RTOS.

Software tools can come from several sources:

  • Software companies that specialize in the embedded market
  • Ported from the GNU software development tools
  • Sometimes, development tools for a personal computer can be used if
    the embedded processor is a close relative to a common PC processor

As the complexity of embedded systems grows, higher level tools and
operating systems are migrating into machinery where it makes sense.
For example, cellphones, personal digital assistants
and other consumer computers often need significant software that is
purchased or provided by a person other than the manufacturer of the
electronics. In these systems, an open programming environment such as Linux, NetBSD, OSGi or Embedded Java is required so that the third-party software provider can sell to a large market.
[edit] Debugging


Embedded debugging
may be performed at different levels, depending on the facilities
available. From simplest to most sophisticated they can be roughly
grouped into the following areas:

  • Interactive resident debugging, using the simple shell provided by the embedded operating system (e.g. Forth and Basic)
  • External debugging using logging or serial port output to trace
    operation using either a monitor in flash or using a debug server like
    the Remedy Debugger which even works for heterogeneous multicore systems.
  • An in-circuit debugger (ICD), a hardware device that connects to the microprocessor via a JTAG or Nexus
    interface. This allows the operation of the microprocessor to be
    controlled externally, but is typically restricted to specific
    debugging capabilities in the processor.
  • An in-circuit emulator replaces the microprocessor with a simulated equivalent, providing full control over all aspects of the microprocessor.
  • A complete emulator
    provides a simulation of all aspects of the hardware, allowing all of
    it to be controlled and modified, and allowing debugging on a normal PC.

Unless restricted to external debugging, the programmer can
typically load and run software through the tools, view the code
running in the processor, and start or stop its operation. The view of
the code may be as assembly code or source-code.
Because an embedded system is often composed of a wide variety of
elements, the debugging strategy may vary. For instance, debugging a
software- (and microprocessor-) centric embedded system is different
from debugging an embedded system where most of the processing is
performed by peripherals (DSP, FPGA, co-processor). An increasing
number of embedded systems today use more than one single processor
core. A common problem with multi-core development is the proper
synchronization of software execution. In such a case, the embedded
system design may wish to check the data traffic on the busses between
the processor cores, which requires very low-level debugging, at
signal/bus level, with a logic analyzer, for instance.
[edit] Reliability


Embedded systems often reside in machines that are expected to run
continuously for years without errors, and in some cases recover by
themselves if an error occurs. Therefore the software is usually
developed and tested more carefully than that for personal computers,
and unreliable mechanical moving parts such as disk drives, switches or
buttons are avoided.
Specific reliability issues may include:

  1. The system cannot safely be shut down for repair, or it is too
    inaccessible to repair. Examples include space systems, undersea
    cables, navigational beacons, bore-hole systems, and automobiles.
  2. The system must be kept running for safety reasons. "Limp modes"
    are less tolerable. Often backups are selected by an operator. Examples
    include aircraft navigation, reactor control systems, safety-critical
    chemical factory controls, train signals, engines on single-engine
    aircraft.
  3. The system will lose large amounts of money when shut down:
    Telephone switches, factory controls, bridge and elevator controls,
    funds transfer and market making, automated sales and service.

A variety of techniques are used, sometimes in combination, to
recover from errors—both software bugs such as memory leaks, and also soft errors in the hardware:

  • watchdog timer that resets the computer unless the software periodically notifies the watchdog
  • subsystems with redundant spares that can be switched over to
  • software "limp modes" that provide partial function
  • Designing with a Trusted Computing Base (TCB) architecture[6] ensures a highly secure & reliable system environment
  • An Embedded Hypervisor
    is able to provide secure encapsulation for any subsystem component, so
    that a compromised software component cannot interfere with other
    subsystems, or privileged-level system software. This encapsulation
    keeps faults from propagating from one subsystem to another, improving
    reliability. This may also allow a subsystem to be automatically shut
    down and restarted on fault detection.
  • Immunity Aware Programming

[edit] High vs low volume


For high volume systems such as portable music players or mobile phones,
minimizing cost is usually the primary design consideration. Engineers
typically select hardware that is just “good enough” to implement the
necessary functions.
For low-volume or prototype embedded systems, general purpose
computers may be adapted by limiting the programs or by replacing the
operating system with a real-time operating system.
[edit] Embedded software architectures


There are several different types of software architecture in common use.
[edit] Simple control loop


In this design, the software simply has a loop. The loop calls
subroutines, each of which manages a part of the hardware or software.
[edit] Interrupt controlled system


Some embedded systems are predominantly interrupt controlled. This
means that tasks performed by the system are triggered by different
kinds of events. An interrupt could be generated for example by a timer
in a predefined frequency, or by a serial port controller receiving a
byte.
These kinds of systems are used if event handlers need low latency and the event handlers are short and simple.
Usually these kinds of systems run a simple task in a main loop also, but this task is not very sensitive to unexpected delays.
Sometimes the interrupt handler will add longer tasks to a queue
structure. Later, after the interrupt handler has finished, these tasks
are executed by the main loop. This method brings the system close to a
multitasking kernel with discrete processes.
[edit] Cooperative multitasking


A nonpreemptive multitasking system is very similar to the simple control loop scheme, except that the loop is hidden in an API.
The programmer defines a series of tasks, and each task gets its own
environment to “run” in. When a task is idle, it calls an idle routine,
usually called “pause”, “wait”, “yield”, “nop” (stands for no operation), etc.
The advantages and disadvantages are very similar to the control
loop, except that adding new software is easier, by simply writing a
new task, or adding to the queue-interpreter.
[edit] Preemptive multitasking or multi-threading


In this type of system, a low-level piece of code switches between
tasks or threads based on a timer (connected to an interrupt). This is
the level at which the system is generally considered to have an
"operating system" kernel. Depending on how much functionality is
required, it introduces more or less of the complexities of managing
multiple tasks running conceptually in parallel.
As any code can potentially damage the data of another task (except in larger systems using an MMU)
programs must be carefully designed and tested, and access to shared
data must be controlled by some synchronization strategy, such as message queues, semaphores or a non-blocking synchronization scheme.
Because of these complexities, it is common for organizations to buy a real-time operating system,
allowing the application programmers to concentrate on device
functionality rather than operating system services, at least for large
systems; smaller systems often cannot afford the overhead associated
with a generic real time system, due to limitations regarding memory size, performance, and/or battery life.
[edit] Microkernels and exokernels


A microkernel
is a logical step up from a real-time OS. The usual arrangement is that
the operating system kernel allocates memory and switches the CPU to
different threads of execution. User mode processes implement major
functions such as file systems, network interfaces, etc.
In general, microkernels succeed when the task switching and intertask communication is fast, and fail when they are slow.
Exokernels
communicate efficiently by normal subroutine calls. The hardware, and
all the software in the system are available to, and extensible by
application programmers.
[edit] Monolithic kernels


In this case, a relatively large kernel with sophisticated
capabilities is adapted to suit an embedded environment. This gives
programmers an environment similar to a desktop operating system like Linux or Microsoft Windows,
and is therefore very productive for development; on the downside, it
requires considerably more hardware resources, is often more expensive,
and because of the complexity of these kernels can be less predictable
and reliable.
Common examples of embedded monolithic kernels are Embedded Linux and Windows CE.
Despite the increased cost in hardware, this type of embedded system
is increasing in popularity, especially on the more powerful embedded
devices such as Wireless Routers and GPS Navigation Systems. Here are some of the reasons:

  • Ports to common embedded chip sets are available.
  • They permit re-use of publicly available code for Device Drivers, Web Servers, Firewalls, and other code.
  • Development systems can start out with broad feature-sets, and then
    the distribution can be configured to exclude unneeded functionality,
    and save the expense of the memory that it would consume.
  • Many engineers believe that running application code in user mode
    is more reliable, easier to debug and that therefore the development
    process is easier and the code more portable.
  • Many embedded systems lack the tight real time requirements of a
    control system. Although a system such as Embedded Linux may be fast
    enough in order to respond to many other applications.
  • Features requiring faster response than can be guaranteed can often be placed in hardware.
  • Many RTOS systems have a per-unit cost. When used on a product that is or will become a commodity, that cost is significant.

[edit] Exotic custom operating systems


A small fraction of embedded systems require safe, timely, reliable
or efficient behavior unobtainable with the one of the above
architectures. In this case an organization builds a system to suit. In
some cases, the system may be partitioned into a "mechanism controller"
using special techniques, and a "display controller" with a
conventional operating system. A communication system passes data
between the two.
[edit] Additional software components


In addition to the core operating system, many embedded systems have
additional upper-layer software components. These components consist of
networking protocol stacks like CAN, TCP/IP, FTP, HTTP, and HTTPS, and also included storage capabilities like FAT
and flash memory management systems. If the embedded devices has audio
and video capabilities, then the appropriate drivers and codecs will be
present in the system. In the case of the monolithic kernels, many of
these software layers are included. In the RTOS category, the
availability of the additional software components depends upon the
commercial offering.
-------------------------
from wikipedia

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(اللهم إليك أشكو ضعف قوتي ، وقلة حيلتي ، وهواني على الناس ، يا أرحم الراحمين ، أنت رب المستضعفين ، وأنت ربي ، إلى من تكلني ، إلى بعيد يتجهمني ، أم إلى عدو ملكته أمري ، إن لم يكن بك علي غضب فلا أبالي ، ولكن عافيتك هي أوسع لي ، أعوذ بنور وجهك الذي أشرقت له الظلمات ، وصلح عليه أمر الدنيا والآخرة ، من أن تنزل بي غضبك ، أو يحل علي سخطك ، لك العتبى حتى ترضى ، ولا حول ولا قوة إلا بك )

يا من يغيث المستغيث
إن لم تغثنا فمن يغيث
وما لنا رب مغيث
سواك يا رب العباد

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مُساهمةموضوع: رد: EMBEDDED SYSTEMS   الأحد 21 مارس 2010, 1:51 am

Shocked Shocked Shocked Shocked Shocked Shocked Shocked Shocked Shocked Shocked Shocked Shocked Shocked Shocked Shocked Shocked Shocked Shocked Shocked Shocked Shocked Shocked Shocked Shocked Shocked
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hilary
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مُساهمةموضوع: رد: EMBEDDED SYSTEMS   الأربعاء 31 مارس 2010, 7:12 pm

thank youuuuuuuuuuuuuuuuuuuuuu Laughing
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~*Prince Of Mesopotamia*~
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مُساهمةموضوع: رد: EMBEDDED SYSTEMS   الثلاثاء 06 أبريل 2010, 2:07 pm

No Comment
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مُساهمةموضوع: رد: EMBEDDED SYSTEMS   الثلاثاء 06 أبريل 2010, 5:26 pm

no comment
خوش فقرة تطلع على يورو نيوز حلوي farao
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M.T.M
نـــائـــب الـــمـــديـــر الـــعـــام
نـــائـــب الـــمـــديـــر الـــعـــام
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مُساهمةموضوع: رد: EMBEDDED SYSTEMS   الإثنين 28 يونيو 2010, 8:21 pm

شكرا على هذا الموضوع......................................................
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M.T.M
نـــائـــب الـــمـــديـــر الـــعـــام
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مُساهمةموضوع: رد: EMBEDDED SYSTEMS   السبت 03 يوليو 2010, 1:40 am

Very Happy
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مُساهمةموضوع: رد: EMBEDDED SYSTEMS   الأحد 04 يوليو 2010, 11:57 am

Cool
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E.T.I
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الــــــمــــــديــــــر الــــــعــــــام
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مُساهمةموضوع: رد: EMBEDDED SYSTEMS   الأربعاء 07 يوليو 2010, 1:27 pm

THNX 4 REPLIES

ــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ
(اللهم إليك أشكو ضعف قوتي ، وقلة حيلتي ، وهواني على الناس ، يا أرحم الراحمين ، أنت رب المستضعفين ، وأنت ربي ، إلى من تكلني ، إلى بعيد يتجهمني ، أم إلى عدو ملكته أمري ، إن لم يكن بك علي غضب فلا أبالي ، ولكن عافيتك هي أوسع لي ، أعوذ بنور وجهك الذي أشرقت له الظلمات ، وصلح عليه أمر الدنيا والآخرة ، من أن تنزل بي غضبك ، أو يحل علي سخطك ، لك العتبى حتى ترضى ، ولا حول ولا قوة إلا بك )

يا من يغيث المستغيث
إن لم تغثنا فمن يغيث
وما لنا رب مغيث
سواك يا رب العباد

الرجوع الى أعلى الصفحة اذهب الى الأسفل
علي
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مُساهمةموضوع: رد: EMBEDDED SYSTEMS   الجمعة 30 يوليو 2010, 10:31 am

يسلموووووووو
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صخر
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مُساهمةموضوع: رد: EMBEDDED SYSTEMS   الجمعة 30 يوليو 2010, 8:01 pm

ليش هو اني افتهمت شي
Very Happy Very Happy Very Happy Very Happy
موضوع رائع شكرا
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مُساهمةموضوع: رد: EMBEDDED SYSTEMS   الجمعة 30 يوليو 2010, 9:03 pm

ههههههههههه Very Happy
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مُساهمةموضوع: رد: EMBEDDED SYSTEMS   الخميس 12 أغسطس 2010, 5:55 pm

Thanks my heart
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EMBEDDED SYSTEMS
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