Top 10 Embedded C Interview Questions and Answers

Embedded C is the most widely used language, because of its compatibility between systems, simplicity, and effectiveness.

Given that embedded systems have limited hardware resources, such as CPU and memory sizes, it is essential to employ these resources intelligently. To achieve this, embedded C normally provides suitable abstractions to interact with the hardware resources.

We can assist you whether you're a college student seeking an embedded systems internship, a recent grad looking for an embedded software career, or an embedded systems engineer looking to switch jobs or organisations.

An Embedded C Developer in India earns around ₹5,70,828 annually. Understanding and practicing embedded C interview questions is a smart move. Take the below provided C programming interview questions as a guide to ace your next interview.

10 Best Embedded C Programming Questions for Job Aspirants in 2023

 

• How does machine code work?

 

Processors only take "machine code" or "object code". Instead of the programmer, it is the computer language. Programmer interpretation of the code is complex and prone to mistakes. All software, whether written in assembly, C, C++, Java, or Ada, must eventually be converted into machine code before being executed by the computer.

 

• Can you tell us the difference between C and embedded C?

 

C is a high-level, general-purpose programming language that may be used to create desktop programs. On the other hand, Embedded C is a variation of the C language utilised to create software for microcontrollers.

Apart from these, the other key differences include

 

• How to make the microcontroller 8051 perform better?

 

Increasing the clock frequency is a straightforward approach to improving the performance of 8051 microcontrollers. The original devices' maximum clock speed was 12MHz. However, the 8051 devices support higher clock speeds. 

The microcontroller's internal modifications, which result in fewer oscillator cycles needed to carry out each machine's instruction, are the best way to boost performance.

 

• Explain UV EPROM

 

UV EPROMs are programmed electrically, just like PROMs. They have a Quartz Window, unlike PROMs, which enables the memory to be erased by exposing the device's internals to UV light.

A UV-opaque label will be applied to the quartz window. This EPROM is capable of withstanding many programs/erase cycles. It can be used for prototyping and is more adaptable than PROMs.

 

• What are Embedded C's key benefits?

 

• Because it is straightforward to comprehend, Embedded C has a fast coding speed.
• Since it consistently completes the same task, it doesn't need hardware modifications, such as additional memory or storage space.
• It only works on one task at a time and is devoted to it.
• The majority of contemporary automatic apps employ it. 

 

• What does the Embedded C volatile keyword mean, and how do you use it?

 

The volatile keyword in embedded C is a type qualifier that stops the compiler from optimising the objects. According to the C standard, the volatile-qualified type object may be changed in ways that are unknown to the implementation. 

In other words, the volatile-qualified object's value may be modified whenever necessary without requiring coding modifications. Whenever a program accesses an object with the volatile qualifier applied, the compiler reloads the value from memory. The only way to verify the value's unanticipated change is to read it from memory.

When working directly with GPIO, interrupt, or flag Registers, the volatile keyword is typically utilised. It can also be utilised with a shared between-threads global variable or buffer.

 

• How segmentation fault errors can be prevented?

 

The following strategies can be used to prevent errors:

• Establishing a pointer correctly
• Using pointers as little as possible
• Troubleshooting

 

• In embedded C, what does a dangling pointer mean?

 

A pointer that directs the user to a memory address that has already been freed by the application and is no longer in use is known as a dangling pointer. Dangling pointers have been left hanging because the programmers occasionally forget to initialise them with valid addresses. 

Deleting or releasing an object from memory without changing the pointer's value results in dangling pointers. A runtime error could occur if you attempt to dereference a dangling pointer.

 

• Can embedded C be integrated into Arduino?

 

Yes, the embedded C codes can be integrated into Arduino. Like other microcontrollers, the AVR microcontrollers found inside Arduino boards are programmed using a subset of C. Since they are used to programme embedded controllers, these subsets are collectively called "Embedded C."

 

• What does "structure padding" in Embedded C mean to you?

 

The C programming language makes use of a notion called structure padding. To align the data in the memory, one or more empty bytes are added between the memory addresses. The compiler performs it automatically to ensure that all of its elements are byte aligned.

Conclusion

We sincerely hope that these embedded systems interview questions and responses will enable you to answer questions asked in your interviews. We strongly advise you to enrol in Skill-Lync’s Embedded C Essentials course if you want to further your abilities. In just ten weeks, this embedded C course will assist you in honing your software development skills.