Embedded systems and technologies

Infinite Loop

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  • Normally, the program those written for other computer platform will never terminate with the infinite loop, but the program written for the embedded system should be terminated by the infinite loop most of the time.
  • In above example we used while (1) for the infinite loop as it required because in embedded software job is never done without infinite loop.
  • So, the functional part of an embedded program is always surrounded by infinite loops.
  • For example, the output of any sensor need to poll continuously or blinking or LED is required t provide status of something, in such cases infinite loop is required.
  • The Role of the Infinite Loop

One of the most fundamental differences between programs developed for embedded systems and those written for other computer platforms is that the embedded programs almost always end with an infinite loop. Typically, this loop surrounds a significant part of the program’s functionality-as it does in the Blinking LED program. The infinite loop is necessary because the embedded software’s job is never done. It is intended to be run until either the world comes to an end or the board is reset, whichever happens first. In addition, most embedded systems have only one piece of software running on them. And although the hardware is important, it is nota digital watch or a cellular phone or a microwave oven without that embedded software. If the software stops running, the hardware is rendered useless. So the functional parts of an embedded program are almost always surrounded by an infinite loop that ensures that they will run forever.

This behavior is so common that it’s almost not worth mentioning. And I wouldn’t, except that I’ve seen quite a few first-time embedded programmers get confused by this subtle difference. So if your first program appears to run, but instead of blinking the LED simply changes its state once, it could be that you forgot to wrap the calls to Toggle Led and delay in an infinite loop


Embedded software development process:


Steps involved in preparing software for the execution on an embedded system.


The Build Process

  • There are a lot of things that software development tools can do automatically when the target Platform is well defined.This automation is possible because the tools can exploit features of the hardware and operating system on which your program will execute. For example, if all of your programs will be executed on IBM-compatible PCs running DOS, your compiler can automate-and, therefore, hide from your view-certain aspects of the software build process. Embedded software Development tools, on the other hand, can rarely make assumptions about the target platform. Instead, the user must provide some of his own knowledge of the system to the tools by giving them more explicit instructions.The process of converting the source code representation of your embedded software into an executable binary image involves three distinct steps. First, each of the source files must be compiled or assembled into an object file. Second, all of the object files that result from the first step must be linked together to produce a single object file, called the relocatable  program. Finally, physical memory addresses must be assigned to the relative offsets within the relocatable  program in a process called relocation. The resultof this third step is a file that contains an executable binary image that isready to be run on the embedded system. The embedded software development process just described is illustrated in this figure, the three steps are shown from top to bottom, with the tools that perform them shown in boxes that have rounded corners. Each of these development tools takes one or more files as input and produces a single output file. More specific information about these tools and the files they produce is provided in the sections that follow.


  • There are lots of software developments tools can do automatically when the target platform is well defined.
  • The process of converting the source code representation of out embedded software into an executable binary i.e. HEX code file.
  • First of all, the source file must be compiled or assembled into an object file. Then all the object files called as re located program must be linked together to produces single object files.
  • Finally make an executable file that is ready to run on the embedded system.
  • Application program are typically developed, compiled and run the host system.
  • Embedded programs are targeted to a target processor that drives a device on controls.
  • What tools are needed to develop, test, and locate embedded software into the target processor and its operating environment?
  • Host: where the embedded software is developed complied, tested debugged, optimized, and prior to its translation into target devices.
  • Target: after development, the code is cross compiled, translated –cross- assembled, Linked and located into the target.

Compiling the embedded program:

  • A compiler is a program or set of programs that translates source code written in a programming language into another computer language.
  • The most common reason for wanting to transform source code is to create an executable program.
  • The name compiler is primarily used for program that translates sources code from a high level programming language to a lower level language
  • If the compiled program can run on a computer whose cpu or OS is different from the one which the compiler runs, the compiler is known as a cross compiler.


Linking and locating of the embedded program:

  • When an assembly source file is assembled by an assembler and a c source is compiled by a c compiler those two objects files can be linked together by a linker to form the final executable.
  • The assembly files can write using any syntax and assembler that the programmer is comfortable with.
  • Also if changes need to be made in the assembly code all of that code exists in a separate file, that the programmer can easily access.


Locator: produces target machine code and the combined code gets copied into the target ROM.

  • The locator doesn’t stays in the target environment; hence all addresses are resolved guided by locating tools and directives, prior to running the code.



Downloading and debugging of embedded program:

  • During the development phase, most of the times you compile code with debug information enabled.
  • The size of the output files usually quite large but this is acceptable.
  • A different approach is to create multiple files, one built without debug information or stripped and at least one other file containing all symbols information.

Question Bank for Unit 1,2& 3.

Unit 1:

1)      Difference between embedded system and general purpose operating system.

2)      Classification of embedded system.

3)      Explain core of embedded system.

4)      Explain embedded firmware.


Unit 2:

1)      Explain charcterstics of embedded system.

2)      Explain operation and non operational Quality attributes of embedded system.

3)      Explain any of the appliaction of embedded system.


Unit 3:

1)      Explain structure of embedded program with the help of program.

2)      Role of infinite looping.

3)      Explian embedded softeware development process.

4)      Use of compiler.

5)      What do you mean by linking and locating.

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30apr Math

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1. Solve each problem. Then decide which the best of the choices given is and fill in the corresponding oval on the answer sheet.

If y = (x + 3)2, then (-2x – 6)2 must equal which of the following?

(A) -4y2
(B) -2y2
(C) -4y
(D) 2y
(E) 4y

Ans: The expression (-2x – 6)2 can be rewritten as [-2(x + 3)]2, which equals 4(x + 3]2.
Since y = (x + 3)2, it follows that (-2x – 6)2 = 4(x + 3)2 = 4y. The correct answer is choice (E).

2.    2

In the figure above, AD is a diameter of the circle with center O and AO = 5. What is the length of arc BCD?






Ans: To solve this problem, it is helpful to draw segment OB in the figure. Since OB and ODare both radii of the circle, they both equal 5. Therefore, the angles opposite these congruent sides of
BOD are congruent and  OBD = 36°. The third angle of the triangle,  BOD, equals
180°- 36°- 36° = 108°. Arc BCD is a fraction of the circumference of the circle and more specifically equals , which equals  The correct answer is choice (D).



If 0 < a  < b   < d  < e  in the equation above, then the greatest increase in  would result from adding 1 to the value of which variable?

(A) a
(B) b
(C) c
(D) d
(E) e


Ans: When the denominator of a fraction is increased, the value of the fraction decreases. Therefore, adding 1 go bd, or e will decrease the sum S. Increasing one of the numerators, either a or c, will increase S. Adding 1 to a changes    to   , thereby increasing S by   . Adding 1 to c changes  to , thereby increasing S by . Since b<d, then . Therefore, adding 1 to a will result in the greatest increase inS. The correct answer is (A).




  1. If k is defined for all postive numbers a and b by a k b= , then
    10 k 2 =



(C)  5


(E)  20


Ans: Substituting 10 for a and 2 for b in the expression  yields
The correct answer is (A).


5. If m and p are positive integers and (m + p) x m is even, which of the following must be true?

(A) If  is odd, then  is odd.
(B) If  is odd, then  is even.
(C) If  is even, then  is even.
(D) If  is even, then  is odd.
(E)  must be even.

Ans: If m is even, then the expression (m + p) x m will always be even and it cannot be determined whether p is even or odd. This eliminates choices (C) and (D). If m is odd, then (m + p) x m will be even only when m + p is even and m + p will be even only when p is odd. The correct answer is (A) since the truth of statement (A) also eliminates choices (B) and (E).

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Embedded systems are commonly found in consumer, cooking, industrial, automotive, medical, commercial and military applications.

Telecommunications systems employ numerous embedded systems from telephone switches for the network to cell 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 consolesdigital camerasDVD playersGPS receivers, and printers. Household appliances, such as microwave ovenswashing machinesand dishwashers, include 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 advancedavionics such as inertial guidance systems and GPS receivers that also have considerable safety requirements. Various electric motors — brushless DC motorsinduction motors and DC motors — use electric/electronic motor controllers.Automobileselectric vehicles, and hybrid vehicles increasingly use 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 uses embedded systems for vital signs monitoring, electronic stethoscopes for amplifying sounds, and various medical imaging (PETSPECTCT,MRI) for non-invasive internal inspections. Embedded systems within medical equipment are often powered by industrial computers.[6] Embedded systems are used in transportation, fire safety, safety and security, medical applications and life critical systems, as these systems can be isolated from hacking and thus, be more reliable.[citation needed] For fire safety, the systems can be designed to have greater ability to handle higher temperatures and continue to operate. In dealing with security, the embedded systems can be self-sufficient and be able to deal with cut electrical and communication systems.

A new class of miniature wireless devices called motes are quickly gaining popularity as the field of wireless sensor networking is increasing. 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 years before the batteries need to be changed or charged.

Embedded Wi-Fi modules provide a simple means of wirelessly enabling any device which communicates via a serial port.

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Embedded systems offer a huge opportunity for the trainee ranging from chip designing to system architecture and formulating testing strategy for software. So why not plan to start a career in embedded engineering?

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Today, embedded systems are everywhere. Although you do not usually interact much with these systems, these tiny computers are present (besides PCs or workstations) in anything electronic that seems intelligent such as mobile phones, smart card readers, set-top boxes, microwave ovens, music systems, digital cameras, TVs, MP3 players, ATMs, automobiles, traffic signals and numerous other gadgets that we come across in our everyday life. Being a unique combination of computer hardware, software and sometimes additional mechanical or other parts, embedded systems focus on one task and do it well. In other words, these sit inside your devices to add an element of smartness to them.

An embedded device is one in which the software is hidden in the hardware on which it runs. Embedded systems are usually designed to perform a specific function within a given time frame—for example, to help you choose for how long your washing machine should run, confer thinking power to the microwave oven and propel rocket launchers into space.

Let’s figure out the opportunities in embedded industry and also if a career in this field could prove to be a good take-off for you.

What’s the market like? 

Spurred by increasing sales of electronics and burgeoning telecom sector, the Indian semiconductor design industry is all set to reach $10.2 billion by 2012, from $7.5 billion in 2010, says a report by the India Semiconductor Association (ISA).

The Indian chip design industry, which comprises very-large-scale integration (VLSI) design, embedded software development and board design, is expected to grow 17.3 per cent year-on-year to reach the whopping figure of $10.2 billion by 2012. This tremendous rate of growth will also require a large number of skilled professionals to increase the quality of work churned out.

The report further adds that the Indian semiconductor design industry employed a workforce of 160,000 in 2010, of which embedded software accounts for as much as 82 per cent employment. Thus highlighting the fact that embedded systems open up a plethora of opportunities for their practitioners.

India’s semiconductor consumption is projected to reach $8.2 billion in 2011, a 15.5 per cent jump from 2010 consumption of $7.1 billion, according to research firm Gartner Inc. Based on this forecast, India is the fastest growing market in terms of semiconductor consumption for 2011.

“Changing demographics, increasing consumer affluence, economic growth and favorable government policy continues to drive the electronic equipment manufacturing industry in India. Numerous global electronic equipment manufacturing companies have set up production facilities in India to take advantage of the growing domestic market, and to cater to neighboring markets in the region.

“Given the low penetration and the growing demand for key electronic equipment such as mobile phones, desktops, laptop computers and LCD TVs, we believe the Indian market will be able to easily sustain high growth rates in the coming years. Therefore we expect India’s semiconductor consumption to grow the fastest across the globe through 2015 at a compound annual growth rate of 15.9 per cent to reach nearly $15 billion. Through 2015, nearly three-fourth of India’s semiconductor consumption will be accounted for by these three electronic equipment segments.

“With India becoming the hub for semiconductor design, the embedded industry offers tremendous job opportunities countrywide. If you plan to enter into this field, you need not worry about the respective job prospects. We require tons of embedded professionals to create all that is possible—be it in telecom, networking, automotive, medical and so on.”
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Career in Embedded System

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Career in Embedded System

Embedded Systems are becoming more and more pervasive, touching virtually all aspects of daily life. From mobile phones to automobiles, industrial equipment, to high end medical devices, home appliances etc. Embedded software today sits at the intersection of all the technologies. The growth of different industry sectors like automotive, telecommunications, aerospace, energy, industrial units, biomedical equipment, consumer goods is highly contributed by the development in the field of Embedded Systems. According to a survey by Frost and Sullivan, an analyst firm, the embedded systems opportunity is expected to touch $360 billion ( in terms of the devices) and $36 billion in terms of the semiconductors by 2015. Another survey by NASSCOM and McKinsey predicts that the jobs in embedded space will increase ten-fold from the current 60,000 professionals to over 6 lakh people by 2015. Companies like TCS, Wipro, L&T, TATA Elexsi, Infosys, Zensar, Tech Mahindra, Patni, VOLVO, NIIT Tech, KPIT Cummins, Airbus etc. are investing heavily in their embedded systems operations in India. With that expectation, in the near future embedded computing will overtake traditional computing and that there may be more engineers working on embedded systems and related services , then on traditional IT. Experts say what IT was in 90’s is where embedded systems stands now and is ready to explode. The future is bright for India with it being pegged to be the next embedded systems hub in the world. A recent study by NASSCOM talks about the Indian Embedded Ecosystem. This ecosystem consists of all the stakeholders in embedded domain namely, the education institutions, end user industries and entrepreneurial organizations. NASSCOM suggests that there is a need to nurture this ecosystem that would catalyze innovation in the Indian embedded industry.

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Embedded systems and technologies

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The future is bright for embedded systems and technologies!!

The tech world is going through unprecedented changes in the last few quarters. Apple and Samsung have taken the mobile phone market leadership to a different level where both of them have surged forward from their nearest rivals, in terms of innovation, technology and the revenue/profits earned in this business. We now see that Software, Operating System players like Microsoft and Google have entered the HW market through their own branded products. The message is loud and clear—the companies are looking at increased business from the consumer and the actions that the consumer carries out in the internet; they are out to influence the consumer side devices as well as the server/network side applications in order to maximise the business. All of these changes are having a huge impact on the traditional eco systems in the mobile, handheld, consumer markets. Only time will tell if the integrated strategies played out by Apple is the way to go for the consumer electronics leaders of the world, though there is an apparent shift in that direction. All of these changes are fuelling tremendous growth in the embedded markets. Some of the trends that we see in the embedded system design markets are as follows:

Increased use of multi-core processor platforms: Traditional embedded systems design principles ensured processor and design simplicity in order to meet the stringent needs of cost, reliability, thermal performance, etc. So the use of multi-core processors was not very common. Of late new process and power conservation technologies are driving the use of multi-core processors in embedded system design without impacting the traditional principles. Enhancements in processor design is looking not only at the increased clock speed, but considers increased efficiency, lower power consumptions and integrated graphic performance.

Connectivity is driving security needs in the devices:

The convergence of devices features and technologies are happening faster than anyone’s imagination these days and the need for connectivity is driving the device designs. All this is adding a security nightmare to preserve personal and professional information from hostile attacks. The embedded system components (processor, operating system, applications) need to have better security features in them in order to tackle these challenges.

Demand for Video processing:

The enhanced processing power in the devices are driving the need to have better video processing for personal and professional data transfers and there is an increasing trend in devices that have video capability being designed. Innovative application use cases are built in to take advantage of the social networking and other converged platforms to share video across devices. Irrespective of the global economic turbulence, there would be continued investments in providing more innovative and efficient solutions coming up in the embedded domain to cater to these trends. In order to be a winner in the embedded market, the companies and individuals need to constantly develop and innovate on new ideas, approaches that can provide efficient, fast, low power, cost effective solutions to the consumers. The above trends of increased video data, security needs and use of complex processors would demand a new level of expertise in providing these solutions.

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