Top 35 Embedded System Courses Interview Questions and Answers

Embedded system Testing positions offers at a variety of top companies. As a result, there are many prospects for experts in the job market. And one of the most challenging aspects of the professional process is technical interviews. One must apply their best talent to impress the interviewers by developing the right first impression in front of the interviewers. So these embedded system courses interview questions and answers will help you to prepare for the interview.

So let’s get started with the essential embedded system courses interview questions and answers.

Top 35 Embedded system courses interview questions and answers.

1. What are Recursive Functions?

Ans: A recursive function is applicable when it is known that the number of recursive calls is not extreme. They declared inline if necessary. 

2.  What is a Memory Leak?

Ans: A memory leak is the collection of uncleared memory. It stalls the execution of the system if it touches adequate space. 

3.  What are the advantages and disadvantages of Embedded systems?

Ans: Advantages: 

• It is quick to load and is tiny in size.
• It is devoted to one distinct task.
• It is easy to manage.
• It is cost-effective.
• Fewer resources are required, such as memory and microprocessors.
• It has excellent performance because the operating system is used for one device.

Disadvantages: 

• It is difficult to upgrade.
• Settings are required to be reset if there is any trouble.
• It is not scalable.
• Limited hardware.
• It is difficult to troubleshoot.
• It is tough to transfer data from one system to the other.

4. What are the reasons for a system to go blank? What are the steps to debug it?

Ans: Top reasons a system could go blanks like:

• Overheated PC
• Accumulated dusk
• Malfunctioning of CPU fans
• Faulty power connections

Steps to debug are: 

• Stabilizing the system and controlling a dust-free environment.
• Creating a relaxed atmosphere for easy passage of air.
• Locating suitable support drivers and installing them.

5. What is the Automotive Embedded System?

Ans: An automotive embedded system is a computer system for an electronic machine that maintains the mechanism of data and devices. 

6.  What is an Embedded C?

Ans: Embedded C is an extended version of the C programming language. It is used to build applications based on micro-controllers like device drivers (camera device drivers, WiFi device drivers, etc.) 

7.  What are the causes of Segmentation fault errors?

Ans: Segmentation fault error is a runtime error that happens because of a few of the following reasons: 

• A pointer may not have an exact address or a memory location.
• If the user tries to evaluate a read-only memory area.
• If the user attempts to free a memory already ensured.

8.  What is a stack overflow error in C?

Ans: Stack overflow error happens if the program accesses the memory beyond its feasible limit. The program finishes and does not execute further instructions when this error occurs. 

9. Why is a ‘volatile’ keyboard used in C?

Ans: When a variable is usually used, the compiler optimizes it and controls the variables in its memory. Therefore, volatility stops the compiler from any optimization. 

10.  What Are Hard and Soft Real-Time Systems?

Ans: The complicated real-time Embedded Systems are the ones that depend on the output very strictly on time. Any late reply or delay cannot be allowed and will continually be appraised as a failure. The soft real-time systems, on the other, are not very rigid as the intricate real-time systems. The system’s performance degrades with the lateness of response, but it is bearable and can be optimized to a certain level to reuse the result.

11. What are the levels of testing in Embedded systems?

Ans: There are four stages of testing in embedded systems: 

• Unit testing
• Integration testing
• System testing
• User acceptance testing

12.  What are the phases of the Software Development Life Cycle?

Ans: There are five main phases of the software development life cycle: 

1. Requirement: In this phase, the customer fills out a required form to write what they need from the product.
2. Analysis: In this phase, the requirements are converted into documents covering all functional requirements.
3. Design: In this phase, the plan of the product is prepared. The requirements are converted into architectural design. This phase includes:
   1. Low-Level Design Documentation (LLD)
   2. High-Level Design Documentation (HLD)
4. Coding: The requirements are converted into a coded form in this phase.
5. Testing: The software under development is tested for product quality in this phase. This includes two types:
   1. Static testing
   2. Dynamic testing
6. Maintenance: In this phase, the care of the product is implemented.

13.  What is Software Quality Assurance?

Ans: Software testing refers to the software developing process: 

• Monitoring and improving the process
• Ensuring that standards and procedures are followed
• Ensuring our problems are found and rectified.

14. What is Equivalence partitioning?

Ans: Equivalence partitioning includes designing a test case to reveal a group or a class of error. 

15. What are some of the standard testing tools?

Ans: Some of the standard testing tools are: 

• Quick Test Professional (QTP)
• WinRunner
• LoadRunner
• TestDirector
• Silk Test

16. How does a combination of functions reduce memory requirements in Embedded systems?

Ans: The amount of code that has to be dealt with is reduced, thus easing the overhead, and redundancy is eliminated in case there is anything familiar among the functions.

Memory allocation is another aspect that is optimized. It also makes sense to group a set of related functions as one unit rather than having them dispersed in the whole program.

17. How does taking the address of Local Variables to result in unoptimized code?

Ans: The most potent optimization for the compiler is register allocation. It executes the variable from the register, then a memory.

Generally, local variables are allocated in registers. However, if we take the address of a local variable, the compiler will not assign the variable to register.

18. Is 8085 an Embedded system?

Ans: It’s not an embedded system. Because it will be a part of an embedded system, it does not work on any software.

19.  What is the role of the Segment Register?

Ans: In the 8086 processor architecture, memory addresses are listed in two parts: segment and offset. Segment values are saved in the segment registers. There are four or more segments included: Code Segment (CS) contains a component of the current instruction (IP is the offset), Stack segment (SS) consists of a stack of the piece (SP is the offset), DS is the segment used by default for most data operations; ES is an extra segment register.

20. What type of registers contains an INTEL CPU?

Ans: Special function registers like accumulator, program controller (PC), data pointer (DPTR), TMOD and TCON (timing registers), three register banks with r0 to r7, and Bit addressable registers like B.

21.  Differentiate Microprocessors and Microcontrollers?

Ans: As you are now fundamentally familiar with a microcontroller And microprocessor, it is easy to recognize the significant contrasts between a microcontroller and a microprocessor.

1. Key difference in both is the presence of external peripherals, whereas microcontrollers have embedded RAM, ROM, and EEPROM. In contrast, we have to use external circuits in the case of microprocessors.

2. As all the peripherals of microcontrollers are on a single chip, it is compact, while the microprocessor is bulky.

3. Microcontrollers are made using complementary metal-oxide-semiconductor technology, which is far cheaper than microprocessors. In addition, the applications created with microcontrollers are more inexpensive because they need lesser external components. In contrast, the overall cost of systems made with microprocessors is high because of the high number of exterior features required for such systems.

4. The processing speed of microcontrollers is about 8 MHz to 50 MHz, but the processing speed of general microprocessors is above 1 GHz, so it works much faster than microcontrollers.

5. Generally, microcontrollers have a power-saving system, like idle mode or power-saving mode, so overall, it uses less power, and also, since external components are low overall power consumption is less. While in microprocessors, there is generally no power-saving system, and many outer parts are used with it, so their power consumption is high compared to microcontrollers.

22. What is Preprocessor?

Ans: A preprocessor is a Program That processes input data to produce output that is used as input to another program. The outcome is said to be a preprocessed form of the input data, which is often used by some subsequent programs like compilers. The amount and kind of processing depending on the preprocessor’s nature.

Some Pre-processors are only qualified to perform relatively Simple Textual Substitutions and small expansions, while others have the power of entire programming languages.

A Common Example from Computer programming is the transformation performed on source code before the next selection step. In some computer languages (e.g., C and PL/I), there is a level of translation known as preprocessing. It can also comprise macro processing, file inclusion, and language extensions.

23.  Which is better, a char, short, or int type for optimization?

Ans: Where possible, it is best to ignore using char and short as local variables. The compiler requires reducing the regional variable size to 8 or 16 bits after each assignment for the types, char, and concise. This is known as sign-extending for signed variables and zero for unsigned variables.

It is provided by shifting the register left by 24 or 16 bits, followed by a signed or unsigned transfer right by the same amount, taking two instructions (zero-extension of an unsigned char takes one instruction).

These shifts can be ignored using int and unsigned int for local variables. This is particularly vital for calculations that first load data into local variables and then process the data inside the local variables.

Even if data is input and output as 8- or 16-bit quantities, it is worth reviewing processing them as 32-bit quantities.

24.  Why do we need virtual device drivers when we have physical device drivers?

Ans: Device drivers are a set of modules/routines to handle a device for which a direct way of communication is not possible through the user’s application program, and these can be thought of as an interface, thus keeping the small system providing for minimalistic of additions of code if any.

Physical device drivers can’t execute all the logical operations required in a system in cases like IPC, Signals, and many more.

The main reason for having virtual device drivers is to mimic specific hardware devices’ behavior without them being present. These could be attributed to the high cost or the unavailability of such devices.

These create an illusion for the users as if they are using the actual hardware, enabling them to carry out their simulation results.

Examples could be the use of virtual drivers in the case of Network simulators and the support of virtual device drivers if a user runs a different OS in a virtual box kind of software.

25. What is the Dirac delta function, its Fourier transform, and its importance?

Ans: Dirac delta is a continuous-time function with units and infinite amplitude at t=0.

The Fourier transform of the Dirac delta function is one. One can get the system response using Dirac delta as an input to the system. It is applied to study the behavior of the circuit. Users use this system behavior to find the output for any information.

26.  What Is The Difference Between A Driver And Firmware?

Ans: Device drivers rely on the operating system and hardware. A driver operates as a translator between the hardware device and the programs or operating systems on which the hardware is installed. Firmware is a software program permanently embedded into a hardware device such as a keyboard, hard drive, BIOS, or video card and is independent to operate the hardware accordingly. It pulls power from the source on which it runs.

27.  What Is The Firmware Of A Computer?

Ans: Firmware is the stored data on a computer or other hardware device’s read-only memory (ROM). It includes instructions on the device’s operating procedure. Firmware such as the ROM or BIOS of any computing devices like laptops, smartphones, or personal computers may have only elementary functions of a machine. Firmware, such as the installed system program, may be the only program that runs on the system and delivers all of its operations.

28. What is a Watchdog timer?

Ans: A watchdog timer is an electronic device committed to a specific operation after a particular time if something goes wrong with a system. This is one of the important embedded system courses interview questions and answers.

29. Why are infinite loops used in embedded systems?

Ans: Embedded systems apply infinite loops to process or monitor a program’s state repeatedly. For example, in a customer support telephone system, a pre-recorded audio file is turned in case the dialer is on hold. 

30.  What are the common errors in Embedded systems?

Ans: Some of the common errors formed in an embedded system are: 

• Data lines malfunctioning
• To locate line malfunctioning because of a short in the circuit
• Some memory locations become unavailable.
• Wrong control signals
• Damage to memory devices

31.  What are some applications of embedded systems?

Ans: The applications are:

• Locate rash driving on highways and alarm the traffic body through a speed-checker device.
• Uncover vehicle movement on highways and control street lights.
• A density-based traffic signal system maintains the signal timing according to the traffic density at junctions.
• To reveal the exact location of a vehicle using a GPS modem.
• For a home automation system with the Android application-placed remote control

34.  What are real-time embedded systems?

Ans: Real-time embedded systems are computer systems that monitor, respond to, or control external environments. 

35.  What is a microcontroller?

Ans: Microcontrollers are self-contained systems installed in devices to control the actions and characteristics of a product. They are also called embedded controllers.

Tips For An Embedded System Interview

Rather than preparing with these embedded system courses, interview questions, and answers, you should also follow some tips. The following tips may guide you through creating a good impression during the embedded engineer interview and getting a job offer:

• Analyze the company. You can visit its official website and social media platforms and search online for company information. Study well about its embedded software development services.
• Practice your Answers. You can prepare mock interviews and video-record them to evaluate your presentation and body language. Give stress on the pace and tone.
• Assess your embedding coding skills. Focus on refining your ability to troubleshoot embedded systems. You should be ready to take a technical test during the interview.
• Arrive on time. Try to arrive at the location at least 15 minutes before the interview starts. That can aid you in staying calm and relaxed during the interview.

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