Embedded Systems Interview Questions and Answers

Pre-processor is system software which can run on a computer's hardware and application. It executes pre-processing of the High-Level Language (HLL). It is the first step of the language processing system. The main tasks of a pre-processor are comments removing, the inclusion of files and expansion of macros.

The purpose of the segment register is to hold the base address of the memory where a particular segment begins. There are different types of segment registers to perform various functions. They are code segment (CS), data segment (DS), stack segment (SS) and extra segment (ES).

It is a piece of hardware which is used for automatic detection of software anomalies. If such defects occur, then it resets the processor. This timer is mainly based on a counter which can count down from some initial value to zero.

The mutex is known as Mutual Exclusion. This is usually used by tasks for giving exclusive access to a shared resource. It can be used for multiple tasks or threads in a system.

Java is used in an embedded system for sophisticated and non-hard real-time tasks. It gives high performance and has small footprints. This reduces development time and errors. Java has a set of standard libraries, so the functionality rewriting is not needed. It provides excellent development productivity which is required in an embedded system.

The full-form of RTOS is a Real-Time Operating System. The primary purpose of an RTOS in an embedded system is to serve the real-time applications which can process the data without any kind of buffer delays. It also looks after the hardware complexities. RTOS is used in an embedded system because it can meet real-time deadlines and can efficiently manage complexities.

Note:- Some times interviewer can give you to make a standard report at the time of embedded system interview questions.

The standard errors that are found in an embedded system are:

• Stack overflow error :- Call stack has a limited amount of memory, and excessive memory usage in this stack can cause the failure. The memory of the call stack contains information of active subroutines in the program.
• Segmentation Fault :- A violation occurs in a program when there is an attempt to access a non-existing memory.
• Memory Leak :- This happens due to the incorrect management of memory allocation such that the memory that is no longer required is not released.
• Fragmentation or Memory corruption :- It happens because memory is altered without an explicit assignment.

It is a pathway to move the data rapidly through digital signals. There three different types of internal buses with are related to the processor. The buses are data, bus, address bus and control bus. All these together make up the system bus.

Both testing and verification are two different methods but these help in checking the application requirements and developments. The primary purpose of both is to provide a correct application — however, the difference between the two.

• Malloc :- The primary function of malloc is to allocate memory at runtime. The size is taken in bytes, and correctly that much space is allocated in the memory.
• Calloc :- It is similar to malloc as it allocates memory at runtime which is defined in stdlib.h. The job of calloc is to take the number of elements, and each element size is in bytes. They will then initialize each of these elements to zero. Finally, a void pointer is returned to the memory.