Embedded Systems Basic Interview Questions (Fundamentals)
These embedded systems basic interview questions are asked in almost every technical round and help interviewers test your fundamentals.
Q1. What is an Embedded System?
An embedded system is a dedicated computer system designed to perform a specific task inside a larger product using both hardware and software.
Example:
Washing machine controller, ATM machine, traffic light controller.
Q2. What are the Main Components of an Embedded System?
An embedded system consists of the following components:
- Microcontroller or Microprocessor
- Sensors and Actuators
- Memory (RAM, Flash, EEPROM)
- Power Supply
- Embedded Software (Firmware)
Example:
In a temperature monitoring system, LM35 is the sensor, Arduino is the controller, Flash stores code, and LCD displays output.
Q3. Why are Embedded Systems Preferred Over Computers?
Embedded systems are preferred because they are:
- Low power consuming
- Cost-effective
- Compact in size
- Highly reliable
- Optimized for one specific task
Example:
A microwave oven uses an embedded controller instead of a PC because it performs limited control operations.
Q4. Difference Between Microcontroller and Microprocessor
| Feature | Microcontroller | Microprocessor |
|---|
| Memory | Inbuilt RAM/ROM | External memory |
| Usage | Embedded devices | Computers |
| Power | Low | High |
| Cost | Low | High |
Example: Arduino vs Intel i5.
Q5. What is Firmware?
Firmware is software stored permanently in flash memory that controls embedded hardware behavior.
Example:
Washing machine control program.
Q6. What is a Real-Time System?
A real-time system produces correct output within a specific time constraint.
Example:
Airbag system, heart monitoring system.
Q7. What is a Cross Compiler?
A compiler that runs on one system but generates code for another system.
Example:
ARM-GCC on Windows compiling code for STM32.
Q8. What is BSP (Board Support Package)?
BSP is a collection of drivers and libraries used to support a specific hardware board.
Example:
STM32 GPIO, UART, and timer drivers.
Q9. What is ROM and RAM?
ROM stores permanent programs
RAM stores temporary execution data
Example:
Firmware in Flash, sensor values in RAM.
Q10. Types of Embedded Systems
- Standalone Embedded Systems
- Real-Time Embedded Systems
- Networked Embedded Systems
- Mobile Embedded Systems
Embedded C Interview Questions for Freshers
Q1. What is the volatile keyword?
It prevents compiler optimization of variables used in hardware registers or interrupts.
Q2. What is const?
It prevents modification of variables.
Q3. Why are pointers important in Embedded C?
Pointers allow direct access to memory and hardware registers.
Q4. Difference between structure and union?
Structure allocates separate memory; union shares memory.
Q5. What is ISR?
Interrupt Service Routine handles hardware interrupts.
Q6. What is static keyword?
Preserves variable value between function calls.
Q7. What is memory leak?
Allocated memory not freed properly.
Q8. What are bitwise operators?
Used to control individual bits.
Q9. What is infinite loop?
Keeps embedded programs running continuously.
Contains function declarations and macros.
Embedded C Pointer Interview Questions
- What is a pointer?
- What is NULL pointer?
- What is dangling pointer?
- What is void pointer?
- What is function pointer?
- What is wild pointer?
- What is pointer arithmetic?
- What is constant pointer?
- Pointer vs Array
- Why pointers are used in drivers
Embedded C Memory Interview Questions
Q1. Difference Between Stack and Heap
| Feature | Stack | Heap |
|---|
| Allocation | Automatic | Dynamic |
| Speed | Fast | Slower |
| Size | Limited | Large |
Q2. Difference Between malloc() and calloc()
malloc does not initialize memory; calloc initializes memory to zero.
Q3. What is Memory Fragmentation?
Memory broken into small non-contiguous blocks.
Q4. What is EEPROM?
Non-volatile memory for small permanent data.
Q5. Flash vs RAM
Flash stores program code; RAM stores runtime data.
Q6. What is DMA?
Transfers data without CPU involvement.
Q7. What is Buffer Overflow?
Exceeding allocated memory limits.
Q8. What is a Linker?
Combines object files into executable.
Q9. What is a Map File?
Shows RAM and Flash allocation.
Q10. What is Segmentation Fault?
Accessing invalid memory.
8051 Microcontroller Interview Questions
- Architecture: 8-bit Harvard
- Timers: Timer0, Timer1
- I/O Ports: P0 to P3
- Interrupts: Five
- Crystal Frequency: 11.0592 MHz
- Internal RAM: 128 bytes
- SFRs: TMOD, IE
- ALE Pin
- Program Counter
- UART
ARM and STM32 Interview Questions
- ARM full form
- Cortex-M series
- NVIC
- SysTick timer
- HAL
- GPIO modes
- DMA
- Boot modes
- Thumb mode
- STM32CubeIDE
UART, SPI, I2C Interview Questions
- Baud rate
- Start and stop bits
- Full duplex communication
- Clock polarity
- I2C addressing
- ACK and NACK
- Chip select
- Bus arbitration
- Data framing
- Error detection
Embedded Systems Debugging and Testing Interview Questions
- Debugging tools
- Program crash debugging
- Infinite loop detection
- Stack overflow detection
- Timing issue analysis
- Watchdog timer
- Hardware debugging
- HIL testing
- Stress testing
- Importance of testing
Embedded Systems Project Interview Questions
Q1. Explain Your Project Architecture
Describe complete hardware and software flow.
Q2. Why Did You Choose This MCU?
Based on power, cost, performance, and peripherals.
Q3. Problems Faced and Solutions
Explain real debugging experience.
Q4. Performance Optimization
Use DMA, efficient loops, memory optimization.
Q5. Testing and Validation
Use logs, measurements, and repeated testing.
Company-Wise Embedded Systems Interview Questions (With Answers)
Bosch Embedded Systems Interview Questions
- Q1. What is AUTOSAR and why is it used?
Answer: AUTOSAR is a standard software architecture used in automotive systems to improve portability and reusability. - Q2. Difference between CAN and LIN?
Answer: CAN is high-speed and used for critical systems, while LIN is low-cost and used for simple devices. - Q3. How do you handle real-time constraints?
Answer: By using RTOS scheduling, priority interrupts, and timer-based execution.
L&T Technology Services (LTTS) Embedded Interview Questions
- Q1. What is BSP in embedded Linux?
Answer: BSP provides drivers and startup code for hardware platforms. - Q2. Explain cross-compilation.
Answer: Compiling code on PC for target embedded hardware. - Q3. How do you debug hardware-software issues?
Answer: Using JTAG, logs, and oscilloscopes.
Tata Elxsi Embedded Interview Questions
- Q1. What is Model-Based Design?
Answer: Designing systems using MATLAB/Simulink models. - Q2. Explain HIL testing.
Answer: Testing embedded software using simulated hardware. - Q3. What is functional safety?
Answer: Ensuring systems work safely in failure conditions.
TCS Embedded Engineer Interview Questions
- Q1. Difference between RTOS and bare-metal?
Answer: RTOS supports multitasking, bare-metal runs single program. - Q2. What is task scheduling?
Answer: Managing execution order of tasks. - Q3. What is watchdog timer?
Answer: Resets system if software hangs.
Infosys Embedded Systems Interview Questions
- Q1. What is bootloader?
Answer: Loads application program at startup. - Q2. Explain memory map.
Answer: Shows memory layout of code and data. - Q3. What is device driver?
Answer: Software that controls hardware devices.
Wipro Embedded Interview Questions
- Q1. What is DMA and its advantage?
Answer: Transfers data without CPU involvement. - Q2. Explain I2C addressing.
Answer: Each device has unique slave address. - Q3. What is ISR?
Answer: Interrupt Service Routine handles interrupts.
HCL Embedded Systems Interview Questions
- Q1. What is embedded Linux?
Answer: Linux customized for embedded devices. - Q2. Explain kernel space and user space.
Answer: Kernel controls hardware, user space runs apps. - Q3. What is device tree?
Answer: Describes hardware to kernel.
KPIT Embedded Interview Questions
- Q1. What is ISO 26262?
Answer: Automotive functional safety standard. - Q2. Explain ASIL levels.
Answer: Safety levels from A to D. - Q3. What is redundancy?
Answer: Backup systems for safety.
Continental Automotive Embedded Interview Questions
- Q1. What is FlexRay?
Answer: High-speed automotive network. - Q2. Explain ECU.
Answer: Electronic Control Unit for vehicles. - Q3. What is fail-safe mode?
Answer: System moves to safe state on failure.
Robert Bosch Automotive Electronics Interview Questions
- Q1. What is ECU flashing?
Answer: Updating firmware in ECU. - Q2. Explain UDS protocol.
Answer: Used for vehicle diagnostics. - Q3. What is bootloader security?
Answer: Protects firmware from unauthorized updates.
Qualcomm Embedded Software Interview Questions
- Q1. What is BSP in Android?
Answer: Hardware support for Android devices. - Q2. Explain ARM TrustZone.
Answer: Provides secure execution environment. - Q3. What is power management?
Answer: Optimizing battery usage.
Intel Embedded Engineer Interview Questions
- Q1. What is x86 architecture?
Answer: Intel processor architecture. - Q2. Explain cache memory.
Answer: Fast memory for frequent data. - Q3. What is multi-core processing?
Answer: Using multiple cores for performance.
Texas Instruments Embedded Interview Questions
- Q1. What is TI RTOS?
Answer: Real-time OS by Texas Instruments. - Q2. Explain MSP430 low-power modes.
Answer: Power-saving operating states. - Q3. What is CCS?
Answer: Code Composer Studio IDE.
Siemens Embedded Interview Questions
- Q1. What is PLC?
Answer: Programmable Logic Controller for automation. - Q2. Explain SCADA.
Answer: System for industrial monitoring. - Q3. What is PROFIBUS?
Answer: Industrial communication protocol.
Honeywell Embedded Systems Interview Questions
- Q1. What is safety-critical system?
Answer: System where failure causes danger. - Q2. Explain redundancy in avionics.
Answer: Multiple backup systems. - Q3. What is real-time monitoring?
Answer: Continuous system observation.
Final Interview Tip
For company interviews, always study their domain (Automotive, IoT, Industrial, Telecom) and connect your answers to real applications.
- Bosch → Automotive
- Qualcomm → Mobile
- Siemens → Industrial
- TI → Microcontrollers
