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.
