10 Embedded Systems interview questions and answers

An embedded system is a specialized computer system designed to perform dedicated functions or tasks within a larger mechanical or electrical system. These systems are built around a microcontroller or microprocessor and are specifically tailored to execute a pre-defined set of tasks, often with real-time constraints and resource limitations. Embedded systems are found in a wide range of applications and devices, making them an integral part of modern technology.

Examples of embedded systems include following.
• Embedded controllers in household appliances like washing machines and microwave ovens.
• Automotive embedded systems for engine control, navigation, and infotainment.
• Industrial automation systems for manufacturing and process control.
• Medical devices such as pacemakers and insulin pumps.
• Consumer electronics like smartphones, smart TVs, and digital cameras.
• Aerospace and defense systems, including avionics and unmanned aerial vehicles (UAVs).

Following is the list of questions and answers on Embedded Systems. This questionnaire will help one pass the job interview for various embedded firmware and hardware positions.

Embedded Systems questions and answers

Question - 1 : What is an embedded system ?
Answer - 1 : An embedded system is a specialized computer system designed to perform dedicated functions or tasks within a larger system. It is typically designed to operate in real-time and is often embedded in everyday devices and appliances.

Question - 2 : What is the difference between a microcontroller and a microprocessor ?
Answer - 2 : A microcontroller is a single-chip computer system that integrates a CPU, memory, input/output peripherals, and timers/counter circuits. It is designed for embedded applications. In contrast, a microprocessor is a central processing unit (CPU) designed for general-purpose computing and requires external components for a complete system.

Question - 3 : Explain the concept of interrupt in embedded systems.
Answer - 3 : Interrupts are events that can halt the normal execution of a program to handle a specific task or event. In embedded systems, interrupts are used to respond to external events or signals quickly, allowing the system to handle real-time tasks.

Question - 4 : What is the purpose of a watchdog timer in embedded systems ?
Answer - 4 : Watchdog timer is a hardware timer that monitors the proper functioning of an embedded system. If the system hangs or encounters an error, the watchdog timer resets the system, ensuring its continued operation. Refer Watchdog timer in microcontroller.

Question - 5 : What are GPIO pins, and why are they essential in embedded systems ?
Answer - 5 : GPIO (General-Purpose Input/Output) pins are pins on a microcontroller or microprocessor that can be configured as either input or output. They are essential for interfacing with external devices, sensors, and controlling other components in embedded systems.

Question - 6 : Explain the concept of real-time operating systems (RTOS) in embedded systems.
Answer - 6 : RTOS is an operating system specifically designed for embedded systems that require deterministic and predictable response times. It ensures that critical tasks are executed within specified time frames, making it suitable for applications with real-time constraints.

Question - 7 : What is the purpose of memory-mapped I/O in embedded systems ?
Answer - 7 : Memory-mapped I/O is a technique where the memory addresses are used to access peripheral registers and control hardware components. It allows the processor to interact with peripherals and sensors as if they were memory locations, simplifying data transfer.

Question - 8 : What is the difference between RAM and ROM in embedded systems ?
Answer - 8 : RAM (Random Access Memory) is used for temporary data storage and is volatile, meaning it loses its data when power is removed. ROM (Read-Only Memory) is non-volatile memory used to store firmware or permanent data that remains even when the power is turned off.

Question - 9 : Explain the concept of "bit-banging" in embedded systems.
Answer - 9 : Bit-banging is a software-driven technique where microcontroller GPIO pins are used to manually manipulate individual bits to implement communication protocols like I2C or SPI, instead of relying on dedicated hardware peripherals.

Question - 10 : What is the importance of power management in battery-powered embedded systems ?
Answer - 10 : Power management is crucial in battery-powered embedded systems to extend battery life. It involves techniques like low-power modes, voltage scaling, and optimizing sleep/wake cycles to minimize power consumption.

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