(SEM IV) THEORY EXAMINATION 2017-18 MICROPROCESSOR AND MICRO-CONTROLLER

The B.Tech Microprocessor & Microcontroller (REC401) question paper from the 2017–18 IV Semester Examination is a comprehensive 70-mark assessment covering the architectural, programming, interfacing, and functional aspects of Intel 8085 microprocessor and Texas Instruments MSP430 microcontroller. The paper is well-structured into three sections, evaluating conceptual clarity, low-level programming skills, interfacing ability, and understanding of serial/parallel communication protocols. 

SECTION A – Fundamentals & Short Answer Questions (14 Marks)

This section consists of 7 short questions (2 marks each), testing essential theoretical knowledge and basic 8085/MSP430 programming. Students are asked to:

Write an 8085 assembly program to add two 16-bit numbers

Define pull-up and pull-down resistor concepts in MSP430

Explain Immediate and Indirect Register Addressing Modes in 8085

List any four GPIO registers

Draw & explain the 8085 Flag Register

Define WDTPW & WDTNMI (Watchdog Timer functionalities)

Write an 8085 program to compute 2’s complement of a 16-bit number

These questions ensure students possess foundational programming syntax and microcontroller basics. 

SECTION B – Intermediate Analytical & Structural Concepts (Any 3 × 7 = 21 Marks)

This section requires clear diagrammatic and technical explanations on:

1. 8085 PIN Diagram

Students draw the full pin layout and explain:

Control signals                           Data & address bus

Interrupts                                   CLK, ALE, RD/WR

Multiplexing actions

2. Watchdog Timer (WDT) in MSP430

Working, resetting mechanism, clock source, and the purpose of system recovery.

3. SIM & RIM Instructions in 8085

Their control word format, enabling/disabling interrupts, reading interrupt masks, and serial input/output control.

4. SPI Protocol with MSP430

Clock polarity, phases, master/slave configuration, data frame and MSP430 SPI registers.

5. 8279 Keyboard Encoder & Display Controller

Interfacing with 8085, scanning modes, debounce logic, and multiplexing techniques.
 

SECTION C – Advanced Programming, Interfacing & Communication (5 × 7 Marks)

This section includes application-level programming, hardware interfacing, block diagrams, and communication protocol explanation.

Q3 – Programming & Architecture

8085 program to sort a list in ascending order (looping, comparison, swapping)
OR

Detailed architecture of 8085, including ALU, timing & control unit, buses, registers, interrupt control, serial I/O, and instruction execution cycle.
 

Q4 – Memory & Peripheral Interfacing

Interface 8085 with 4KB EPROM & 2KB RAM using a 3×8 decoder, including address range calculation
OR

Interface 8255 PPI with 8085, explaining ports, control word, and application examples.
 

Q5 – MSP430 Block Diagram & Addressing Modes

Draw and explain MSP430x5x functional block diagram
OR

Explain all addressing modes of MSP430 with examples.

Q6 – PWM & GPIO Resistors

Working of PWM, block diagram, duty cycle explanation
OR

Various GPIO resistors in MSP430x5xx, such as:

Pull-up/Pull-down

Input/output

Schmitt trigger input

Open-drain
 

Q7 – DMA & I2C Protocol

Different DMA transfer modes (single, block, burst, continuous)
OR

I²C communication format:

Start/Stop conditions

Address frame

ACK/NACK

Data frame

OVERALL ESSENCE OF THE PAPER

This question paper thoroughly assesses a student’s proficiency in:
8085 assembly programming
MSP430 architecture & I/O handling
Data transfer, memory mapping & interfacing
Interrupt structure, timers & watchdog mechanisms
Serial/parallel communication protocols (SPI, I2C)
Microcontroller GPIO, resistors, and PWM
Peripheral interfacing (8255, 8279, EPROM/RAM)

It serves as a complete evaluation of both hardware understanding and low-level programming essential for embedded systems and microcontroller-based applications.