BE Computer Engineering (Pokhara University) Embedded System (PU, ELX 320) Question Paper 2078
This is the official BE Computer Engineering (Pokhara University) Embedded System (PU, ELX 320) question paper for 2078, as set in the regular annual examination. It carries 100 full marks and a time allowance of 180 minutes, across 12 questions. On Kekkei you can attempt this Embedded System (PU, ELX 320) past paper online with a timer, get instant AI feedback and step-by-step solutions, and track the topics where you lose marks — completely free. Whether you are revising for your BE Computer Engineering (Pokhara University) Embedded System (PU, ELX 320) exam or solving previous years' question papers, this 2078 paper is a great way to practise under real exam conditions.
Section A: Long Answer Questions
Attempt all / any as specified.
(a) Define an embedded system and explain its essential characteristics with at least four real-world examples. (6)
(b) With a neat block diagram, explain the basic architecture of a microcontroller-based embedded system, clearly describing the role of the CPU, program memory, data memory, I/O ports and the system clock. (8)
(a) Compare the Harvard and Von Neumann architectures and state which one the 8051 microcontroller follows, giving reasons. (6)
(b) Write an Embedded C program for the 8051 to generate a 1 kHz square wave on pin P1.0 using Timer 0 in mode 1 (16-bit timer). Assume a crystal frequency of 11.0592 MHz and clearly show the timer reload value calculation. (8)
(a) Differentiate between a hard real-time and a soft real-time operating system with suitable examples. (4)
(b) Explain the working of a preemptive priority-based scheduler in an RTOS. (6)
(c) Three periodic tasks have the following parameters — T1: period 25 ms, execution 5 ms; T2: period 50 ms, execution 15 ms; T3: period 100 ms, execution 30 ms. Compute the total CPU utilization and determine whether the task set is schedulable under Rate Monotonic Scheduling. (6)
(a) Describe the typical embedded system design flow from requirement specification to final deployment, explaining the purpose of hardware/software co-design and the role of simulation and emulation. (7)
(b) Design an embedded temperature-monitoring system that reads an analog temperature sensor (LM35), and turns ON a cooling fan when the temperature exceeds 40 deg C. Draw the interfacing block diagram and outline the control algorithm. (5)
Section B: Short Answer Questions
Attempt all / any as specified.
Compare the I2C and SPI serial communication protocols in terms of number of signal lines, addressing scheme, speed, and number of devices supported. State one application of each.
(a) Differentiate between polling and interrupt-driven I/O. (3)
(b) Describe the sequence of events that occurs in a microcontroller when an interrupt is triggered, and explain the function of the Interrupt Service Routine (ISR) and the interrupt vector table. (3)
Explain the frame format of asynchronous UART communication. For a baud rate of 9600 bps with 8 data bits, 1 start bit, 1 stop bit and no parity, calculate the time required to transmit one character and the effective data throughput in bytes per second.
Explain how a DC motor can be interfaced with a microcontroller and its speed controlled using Pulse Width Modulation (PWM). Why is a driver circuit such as an L293D required between the microcontroller and the motor?
What is the difference between the keywords volatile and const in Embedded C? Give one practical scenario in embedded programming where the volatile qualifier is essential and explain what bug may occur if it is omitted.
Differentiate between a microprocessor and a microcontroller. List the major functional blocks present on a typical microcontroller chip and state two advantages of using a microcontroller in embedded applications.
(a) What is a semaphore? Explain how a counting semaphore differs from a binary semaphore (mutex). (3)
(b) Explain the priority inversion problem in an RTOS and briefly describe how priority inheritance solves it. (3)
Write short notes on any TWO of the following: (a) Watchdog timer; (b) Cross-compiler and toolchain; (c) Memory-mapped vs port-mapped I/O; (d) Power management in battery-operated embedded devices.