CS-404 Computer Org. & Architecture - Jun 2026 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
   aExplain Stack based central processing unit organization with block diagram.
   How to answer

   • Define stack-based CPU organization and 0-address instructions
   • Describe stack pointer, PUSH/POP operation and LIFO
   • Explain ALU interaction with top of stack
   • Provide block diagram with memory stack, SP, ALU, control
2. 7 Marks
   bWhat is the Difference between hardwired and micro programmed control unit. Explain each component of hardwired control unit organization.
   How to answer

   • Define hardwired control and microprogrammed control
   • Tabulate differences: speed, flexibility, cost, implementation
   • Describe hardwired components: instruction register, decoder, sequencer, control logic gates
   • Explain generation of control signals
3. 7 Marks
   aWAP to evaluate arithmetic expression using stack organized computer with 0-address instruction. $X= (A-B)*(((C-D*E)/F)/G)$
   How to answer

   • Convert $X=(A-B)*(((C-D*E)/F)/G)$ to postfix for stack
   • List 0-address instructions PUSH, SUB, MUL, DIV
   • Show step-wise stack contents
   • Write complete program sequence
4. 7 Marks
   bEvaluate $(-13)*(8)$ using Booth's Multiplication algorithm and draw the flow diagram of this process.
   How to answer

   • Represent -13 and 8 in binary with sign handling
   • Apply Booth's recoding steps with A, Q, Q-1 and arithmetic shift
   • Show cycle-wise table to get -104
   • Draw flowchart of Booth's multiplication algorithm
5. 7 Marks
   aExplain the concept of instruction pipelining and describe different stages of instruction pipelining and their functions.
   How to answer

   • Define instruction pipelining and overlap of fetch-decode-execute
   • List stages: IF, ID, OF, EX, WB
   • Explain function of each stage
   • Mention speedup and hazards briefly
6. 7 Marks
   bExplain the concept of vector processing and its advantages over scalar processing.
   How to answer

   • Define vector processing vs scalar processing
   • Explain SIMD and vector instructions, pipelined ALU
   • List advantages: speed, throughput, efficiency for arrays
   • Give example applications
7. 7 Marks
   aExplain the architecture of Intel multicore processors with suitable diagrams.
   How to answer

   • Describe multicore concept: multiple cores on single chip
   • Explain shared cache, interconnect, memory controller
   • Provide suitable block diagram of Intel multicore
   • Mention advantages: parallelism, performance
8. 7 Marks
   bDescribe the working principle of the PCI Bus. How does it improve communication between peripherals and the processor?
   How to answer

   • Define PCI bus and its features
   • Explain bus arbitration, data transfer and plug-and-play
   • Explain bridge between processor and peripherals
   • Show how speed and efficiency improve
9. 7 Marks
   aDraw the flow chart of Restoring division operation and perform the division process of 10100 by 101 using non-restoring Booth's division method.
   How to answer

   • Draw flowchart of restoring division algorithm
   • Explain non-restoring steps: subtract, shift, add if negative
   • Perform $10100$ divided by $101$ step-wise
   • Obtain quotient and remainder
10. 7 Marks
    bWhat is meant by cache mapping? Discuss different mapping techniques with examples.
    How to answer

    • Define cache mapping and need for placement
    • Explain direct, associative and set-associative with example
    • Show address field division and hit/miss logic
    • Compare advantages and disadvantages
11. 7 Marks
    aExplain the architecture and working of the SCSI Bus with a suitable diagram.
    How to answer

    • Define SCSI bus and its devices
    • Explain architecture: initiator, target, daisy chain
    • Describe working: arbitration, selection, data transfer phases
    • Provide suitable diagram
12. 7 Marks
    bCalculate the page fault for a given string with the help of LRU, FIFO and Optimal page replacement algorithm, size of frames = 4 and string 12342156212376321236.
    How to answer

    • State reference string and 4 frames
    • Simulate FIFO, count faults step-wise
    • Simulate LRU and Optimal replacement
    • Compare total page faults for three algorithms
13. 7 Marks
    aExplain the concept of Asynchronous data transfer with methods.
    How to answer

    • Define asynchronous transfer and need for handshaking
    • Explain strobe control method
    • Explain handshaking method with source/destination initiated
    • Mention applications
14. 7 Marks
    bWrite short notes on any **two** of the following :

    1. i)Auxiliary Memory
    2. ii)Virtual memory
    3. iii)ROM
    How to answer

    • Select any two from auxiliary, virtual, ROM
    • Define each with characteristics and purpose
    • Explain organization and examples
    • Mention advantages/limitations
15. 7 Marks
    aDiscuss the significance and importance of DMA and elaborate the working of DMA Controller.
    How to answer

    • Define DMA and need to offload CPU
    • Explain DMA controller registers and signals: BR, BG, address
    • Describe transfer modes: burst, cycle stealing
    • Explain working sequence with block diagram
16. 7 Marks
    bDifferentiate between the following :

    1. i)RISC & CISC
    2. ii)Horizontal & Vertical micro-programmed control unit
    How to answer

    • Define RISC vs CISC with features and examples
    • Compare on instruction size, addressing, pipelining, compiler
    • Define horizontal vs vertical microprogrammed control
    • Compare on control word width, decoding, speed, storage