EC-604-A Microcontroller and Embedded System - Jun 2025 Question Paper

Under each question, How to answer lists the points an answer should cover, outlined by CampusPrep from the syllabus. Check the details against your textbook.

1. 7 Marks
   aDescribe the working of DAC interfacing with 8051. Illustrate with timing diagrams and application examples.
   How to answer

   • DAC interfacing circuit with 8051 port and DAC0808/MC1408 connections
   • Working: digital data latch, current to voltage conversion
   • Timing diagram of WR/CS and data latch operation
   • Application examples e.g. waveform generation, motor control
2. 7 Marks
   bDesign an 8051-based data acquisition system. Discuss its hardware components.
   How to answer

   • Block diagram of 8051-based data acquisition system
   • Hardware components: sensors, signal conditioning, ADC, 8051, display/storage
   • Working flow of data acquisition
   • Design considerations
3. 7 Marks
   aWrite a program in embedded C to transmit the message "HELLO" via the serial port using Mode 1 of 8051.
   How to answer

   • Serial port initialization for Mode 1, timer for baud rate
   • SCON, TMOD, TH1 configuration steps
   • Embedded C code to transmit string HELLO via SBUF with TI polling
   • Use of delay and continuous transmission logic
4. 7 Marks
   bExplain the various serial communication modes of 8051. Compare mode 1 and mode 3 in terms of control and applications.
   How to answer

   • Serial modes 0,1,2,3 baud rates and framing
   • Control bits SM0, SM1, SM2, REN
   • Comparison of Mode 1 vs Mode 3 in control and applications
   • Typical use cases for multiprocessor communication
5. 7 Marks
   aConsider the following code written for Intel 8096 and answer the questions given below. LD R1, #05H LD R2, #03H MPY R1, R2 ST R1, 0200H

   1. i)What value will be stored at 0200H?
   2. ii)What would happen if MPY was replaced by DIV?
   3. iii)Is there any overflow risk?
   How to answer

   • LD R1,#05H and LD R2,#03H loads, MPY multiplies to 0FH
   • ST stores result at 0200H
   • Effect of DIV: quotient and remainder handling
   • Overflow risk analysis for 8/16-bit result
6. 7 Marks
   bDraw the functional block diagram of 8096 and explain each block in detail. How is it superior to 8051?
   How to answer

   • Functional block diagram of 8096: CPU, PTS, ADC, timers, serial port
   • Function of each block in detail
   • 16-bit architecture, high-speed I/O advantages
   • Comparison points showing superiority over 8051
7. 7 Marks
   aExplain the addressing modes of 8096 with suitable code examples.
   How to answer

   • List of 8096 addressing modes: direct, indirect, indexed, immediate
   • Syntax and example code for each mode
   • When each mode is used
   • Effect on instruction length and execution
8. 7 Marks
   bDefine an Embedded system. How is it different from a general-purpose computing system? Explain the characteristics and quality attributes of embedded systems.
   How to answer

   • Definition of embedded system
   • Difference from general-purpose computing system
   • Characteristics: real-time, resource constrained, dedicated function
   • Quality attributes: reliability, power, cost, maintainability
9. 7 Marks
   aDifferentiate between general purpose processors, application-specific processors, and single-purpose processors. When should each be used?
   How to answer

   • Definitions of GPP, ASPP, SPP
   • Comparison on flexibility, performance, cost, power
   • When to use each with examples
   • Trade-offs summary
10. 7 Marks
    bClassify embedded systems based on performance and complexity. Provide industrial examples for each type.
    How to answer

    • Classification criteria: small, medium, sophisticated / stand-alone, real-time, networked
    • Performance and complexity features
    • Industrial example for each type
    • Selection considerations
11. 7 Marks
    aDescribe the architecture of the ARM processor. Highlight its RISC features and use in mobile embedded systems.
    How to answer

    • ARM architecture: load-store, registers, pipeline
    • RISC features: fixed instruction length, single-cycle, large register file
    • Use in mobile embedded systems: low power, high performance
    • Block diagram of ARM core
12. 7 Marks
    bWhat are DSP processors? Discuss their role and special features compared to general-purpose processors.
    How to answer

    • Definition of DSP processors
    • Role in signal processing applications
    • Special features: MAC, Harvard, DMA, fixed-point
    • Comparison with general-purpose processors
13. 7 Marks
    aWhat is a Watchdog timer? How does it help in improving system reliability? Give an example with timing diagram.
    How to answer

    • Definition and purpose of watchdog timer
    • Working: timeout and system reset mechanism
    • Timing diagram showing kick/refresh vs reset
    • Example improving reliability
14. 7 Marks
    bDescribe the working of a keyboard controller. How are key-presses scanned, debounced and processed?
    How to answer

    • Keyboard matrix and controller interfacing
    • Scanning procedure row-column
    • Debouncing hardware/software method
    • Key code processing and interrupt
15. 14 Marks
    Write short notes on (any two):

    1. a)Interrupt controllers
    2. b)16-bit PIC and 32-bit DSPIC microcontrollers
    3. c)Von Neumann v/s Harvard architecture
    How to answer

    • Two topics selected from three options
    • Definition, diagram and key points for each
    • Applications and advantages
    • Comparison where relevant e.g. Von Neumann vs Harvard