About this previous year paper
INTRODUCTION TO MICROPROCESSOR – B.Tech (Semester IV), REC-405
This is a 3-hour, 70-mark theory examination focusing on microprocessor fundamentals, assembly programming, memory interfacing, instruction cycles, interrupts, and peripheral devices.
The paper is divided into three major sections: conceptual, descriptive, and detailed analytical/programming questions.
SECTION A — Short Answer Questions (2 × 7 = 14 Marks)
This section tests quick conceptual knowledge of 8085/8086 microprocessors.
Topics include:
Function of accumulator Memory chip requirement calculation
CALL & RET instructions HOLD and HLDA pin functions
Logical vs physical address Flag register of 8086
Meaning of pipelining
These questions evaluate definitions, basic hardware concepts, and instruction-level understanding.
SECTION B — Descriptive Questions (7 × 3 = 21 Marks)
Attempt any 3 out of 5.
This section evaluates knowledge of programming, microprocessor evolution, counters, timing delays, and peripheral chips.
Topics include:
Evolution & generations of microprocessors
Assembly program to load, subtract, convert to magnitude, and output via PORT1
Counters & delay generation using register pairs
BCD addition assembly program
Modes of operation of 8254/8253 programmable timer
These questions test programming logic, architecture understanding, and peripheral device usage.
SECTION C — Long Answer Questions (7 marks each)
Each question offers a choice (a or b).
These are deep, diagram-based and program-based questions requiring strong conceptual understanding.
Q3 – Memory Interfacing & Architecture
Interfacing 8 KB EPROM with 8085 using 2K × 8 chips + address decoding
Architecture of 8085 with programmer’s model
Q4 – Instruction Cycle & Instruction Set
Timing diagram of opcode fetch cycle
Classification of instruction set of 8085 with examples & explanations
Q5 – Interrupts & Delay Calculations
Classification of interrupts, hardware & software interrupts in 8085
16-bit count calculation to generate 2-second delay using loops
Q6 – Assembly Language Programs
Converting binary to ASCII-Hex (XX20H → XX30H, XX31H)
Converting BCD (56 BCD) to binary (XX50H → XX60H)
Q7 – Peripheral Interface & 8086 Architecture
8259 Programmable Interrupt Controller block diagram + ICWs
Architecture of 8086 + physical address calculation (CS=9105H, IP=1724H)
These questions test in-depth knowledge of microprocessors, addressing techniques, cycles, peripheral ICs, and program execution flow.
OVERALL PURPOSE OF THE EXAM
This question paper examines whether a student can:
Understand 8085/8086 architectures
Write and analyze assembly language programs
Perform memory interfacing and address decoding
Use timing diagrams & instruction cycles properly
Work with interrupts and programmable devices (8259, 8253/54)
Apply delay generation, arithmetic operations, BCD/binary conversions
Calculate memory requirements and physical addresses
This ensures strong foundational skills in microprocessor systems, essential for embedded systems, IoT, robotics, and digital electronics.