Top 21 Embedded Systems Interview Questions and Answers

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The boundless universe of technology doesn’t cease to exist. It is omnipresent in every place we visit. Thus in the real world, technology’s applications have paved their way into every facet of our lives. From a simple task to a highly complex problem, we have the solution just a click away! It is considerably apparent that tech-driven fields are skyrocketing, and thus, it includes embedded systems as well. Are you in need of embedded systems interview questions? It may seem like a hard nut to crack, but with patience and practice, you have the potential!

Research has stated that the embedded systems market will surge by 2025. They play an integral role in our everyday existence. These systems perform specific tasks in larger systems. Generally, the devices we use in routine activities have these systems. A few examples are smartphones, digital watches, medical equipment, etc. Hence, we have listed the top embedded systems interview questions. Let us delve into them in detail.

1. Explain embedded systems in simpler terms.

It is a computer system designed to perform specific tasks. They are optimized to meet specific requirements.

2. Comment on the essential components of the embedded system.

An embedded system has three components. They are:

1. Hardware: It encompasses the physical components of a computer system. Moreover, it comprises the processor, memory, etc.
2. Software: It is the intangible part of a computer system and usually ensures the availability of memory, processor speed, etc.
3. Real-time operating system: It is designed to control tasks. It executes the tasks based on a predetermined time.

3. What do you understand by interrupt latency?

Interrupt latency is a measure of a system’s ability to respond to outside events. The system is responsive if the interrupt latency is shorter.

4. What is a watchdog timer?

A watchdog timer is an electronic device that is dedicated to a specific operation if a system becomes unresponsive.

5. Mention common errors in embedded systems.

Some commonly found errors are:

1. Malfunctioning of data lines
2. Damage to memory devices
3. Certain memory locations become inaccessible.
4. Wrong control signals

6. What is a memory leak?

It is the accumulation of unclear memories. Further, it causes your system to have performance issues.

7. Explain real-time embedded systems.

Real-time embedded systems are computer systems that generally monitor, respond to, and control external environments. Furthermore, this external environment is connected to the computer system through sensors.

8. Comment on the buses used for communication in the embedded system.

The buses used for communication in the embedded system are:

I2C is generally used for communication between multiple ICs.
CAN is broadly used in automobiles.
USB is typically used for communication between the CPU and devices like a mouse.

9. What is the purpose of Malloc?

Malloc stands for memory allocation. It is generally used to dynamically allocate memory to different variables.

10. Define semaphore and mention its purpose.

It is an abstract datatype or a variable used to control access. Further, its purpose is to share access to files and a common memory space.

The next set of Embedded Systems Interview Questions is as follows:

(https://youtu.be/LLVcy3lIErY?si=ULKzC8_wEf_ZLmZW)

11. Mention some of the common testing tools.

The common testing tools include:

1. WinRunner
2. LoadRunner
3. Silk Test
4. Quick Test Professional

12. What do you understand by embedded C?

This is an extension of the C programming language. It is used to develop microcontroller-based applications such as device drivers (camera device drivers, WiFi device drivers, etc.).

13. When does a stack overflow error happen?

In C, a stack overflow error happens when a program uses up all its available memory for managing functions and variables, causing a crash.

14. What do you understand by equivalence partitioning?

It is a software testing technique in which input data is grouped into sets that are expected to behave similarly. Further helping to effectively validate software behaviour.

15. Specify the use of timers in embedded systems.

Numerous uses of timers in embedded systems include:

1. Time-division multiplexing
2. Time slices for various tasks
3. A real-time clock for the system
4. Recording the count value in a timer for an event
5. Determining the time interval between two events

16. What does DMA address deal with?

Direct Memory Access (DMA) is a hardware device that allows input/output (I/O) devices to access memory directly with less processor involvement.

17. Explain why infinite loops are used in embedded systems.

Infinite loops keep embedded systems running, handling events, tasks, and real-time operations continuously without stopping. Hence, ensuring functionality.

18. How can interrupt latency be reduced?

We can reduce interrupt latency by:

By keeping ISRs shorter.
By preventing inappropriate APIs.
Maintaining ISRs short.

19. What are the causes of a system going blank?

The causes for a system to go blank are:

Overheated PC
Defective power connection
Malfunctioning CPU fans, etc.

20. What are the levels of testing for embedded systems?

There are four levels of testing for embedded systems.

Unit testing
Integration testing
System testing
User acceptance testing.

21. What is the difference between mutexes and semaphores?

Mutex can be released by the thread that acquired it, whereas, semaphores can be signalled from any other thread or process.
The former is mainly used to protect critical parts of code, ensuring that only one thread can execute that code at any given time. However, the latter is used for situations where you want to allow several threads to access a shared resource concurrently.

Conclusion

In conclusion, the embedded systems market offers numerous scopes, and interested candidates wanting to sail off their journey in this direction should prepare the embedded systems interview questions in depth. In addition to technical questions, one should practice behavioural questions. Embedded system interview questions are designed in a way to evaluate your knowledge regarding the technical side. Hence, to crack the interview, try to practice more and build up your confidence.

Recommended course

Are you currently seeking a professional course in the dynamic field of embedded systems? If so, you might find yourself excited about the endless possibilities this realm offers. If you possess foundational knowledge in electronics and C programming, and you’re aspiring to start a career in embedded systems, your journey could begin by enrolling in Henry Harvin’s comprehensive Embedded System Course. Hence, this course serves as a crucial foundational step on the path toward mastering embedded processor design. Upon successful completion of the Embedded Systems course, you’ll find yourself presented with a myriad of job opportunities. These opportunities not only promise growth but also hold the potential to take your career to new heights within the hardware industry.

FAQs

1. What is the scope of embedded systems?

The scope of embedded systems is expanding with the advancement of technology. Therefore, they are used in medical devices, consumer electronics, and home appliances.

2. What are the required skills for a career in embedded systems?

You should have a strong foundation in programming languages like C and C++. However, basic knowledge of electronics is an advantage.

3. What job roles does this field offer?

There are numerous job roles in this field, including embedded software engineer, firmware developer, embedded systems designer, IoT developer, real-time systems engineer, and hardware engineer, among others.

4. Is a degree in electrical engineering or computer science necessary for a career in the field of embedded systems?

Although possessing a degree in electrical engineering, computer science, or a closely related area can be beneficial, it is not always obligatory.