About this previous year paper
This examination evaluates a student’s understanding of computer architecture, digital design principles, processor organization, memory hierarchy, I/O mechanisms, pipelining, and data transfer techniques.
The paper is divided into three structured sections, assessing conceptual clarity, analytical ability, and technical explanation skills.
SECTION A – Short Answer Questions (14 Marks)
Seven questions × 2 marks each
This section tests essential definitions and basic concepts of COA.
Topics Covered:
1. Types of Buses in Computer Architecture
Students recall data bus, address bus, control bus, and system bus roles.
2. Types of Multipliers
Booth multiplier, array multiplier, Wallace tree multiplier etc.
3. Phases of Instruction Cycle
Fetch → Decode → Execute → Memory Access → Write Back.
4. Working of Control Unit
How the control unit interprets instructions, generates control signals, and coordinates CPU components.
5. Locality of Reference
Temporal and spatial locality; relevance to cache organization.
6. 2½ D Memory Organization
Stacked memory layers enabling high bandwidth and reduced latency.
7. Synchronous vs Asynchronous Serial Data Transfer
Difference in timing, clock dependency, and communication reliability.
This section checks conceptual accuracy and familiarity with fundamental COA terminologies.
SECTION B – Application-Based Analytical Questions (21 Marks)
Attempt any three × 7 marks
These questions require detailed explanations, computations, and design-level thinking.
1. Bus Arbitration & Daisy Chaining
Definition, need for bus arbitration, priority resolution, and implementation of Daisy-Chaining method.
2. Booth’s Multiplication Algorithm
Perform signed multiplication using Booth’s algorithm for:
(-12) × (-18)
Show step-by-step encoding, bit operations, partial products, and final result.
3. Pipelining
Meaning, advantages, hazards, and detailed explanation of pipeline stages such as:
IF → ID → EX → MEM → WB.
4. Memory Classification & Magnetic Disk
Memory types—sequential, direct, associative, random.
Explain construction of magnetic disk, platters, read/write heads, tracks, sectors, seek time, latency & access time.
5. Interrupt Initiated I/O vs Programmed I/O
Difference in CPU involvement, response time, overhead, and efficiency.
This section evaluates the student’s understanding of logical operations within computer systems.
SECTION C – Long Descriptive / Higher-Order Questions (35 Marks)
One question from each group × 7 marks
3. Processor Organization / Memory Stack vs Register Stack
Option A – Processor Organization
Explain CPU structure, single accumulator organization, general register organization, and stack organization with diagrams.
Option B – Memory Stack vs Register Stack
Difference in implementation, speed, access pattern, and CPU usage.
4. CLA Adder / IEEE Floating-Point Representation
Option A – Carry Look Ahead Adder
Explain carry propagation, generate & propagate signals, logic for 4-bit CLA adder, and block diagram.
Option B – IEEE-754 Single Precision Representation
Convert decimal numbers to 32-bit IEEE floating point:
(i) 85.125
(ii) -307.1875
Show binary, exponent biasing, mantissa, and sign bit.
5. Instruction Execution Cycles / Control Unit
Option A – Instruction Cycle
Explain Fetch, Decode, Operand Fetch, Execution, and Result Storage phases.
Option B – Hardwired vs Microprogrammed CU
Concept, structure, speed differences; detail components of hardwired CU.
6. Cache Mapping / Direct Mapping
Option A – Cache–Main Memory Mapping
Given M1: 16K, M2: 1M, 8-word blocks, 256-word set associative:
• Explain mapping
• Calculate effective access time for hit ratio = 0.95.
Option B – Direct Mapping Technique
With memory = 64k×16 and cache = 1k words, block size = 4 words:
• Identify bits for tag, block, word
• Calculate number of blocks in cache.
7. Asynchronous Transfer / DMA & Other Modes
Option A – Asynchronous Data Transfer
Explain strobe control, source-initiated strobe, destination-initiated strobe, and handshaking.
Option B – Data Transfer Modes
Programmed I/O, Interrupt-driven I/O, DMA.
Explain why DMA is fastest and CPU-independent.