CSC116 Digital Logic

Digital Logic TU Board 2078 question paper

12 questionsSit this paper (timed)

Tribhuvan University

Bachelor of Science in Computer Science and Information Technology

Semester 1 · TU Board 2078

Course Title: Digital Logic (CSC116)

Full Marks: 60Pass Marks: 24Time: 3 hours

Candidates are required to give their answers in their own words as far as practicable. The figures in the margin indicate full marks.

Group A

(2 × 10 = 20)

  1. 1.

    Design the sequential circuit with respect to the following state diagram using J-K flip flops.

    [figure in the original paper]

    10
  2. 2.

    Implement F = Σ(0, 2, 3, 4, 7) using

    1. Multiplexer
    2. Decoder
    3. PLA
    10
  3. 3.

    Difference between synchronous and asynchronous counter. Design mode-7 synchronous counter using T-flip flop. Show necessary truth tables and k-maps.

    10

Group B

Attempt any two questions(2 × 5 = 10)

  1. 4.

    Provide one example where shift right operation can be used. Explain parallel-in-parallel-out register.

    5
  2. 5.

    Carry out the following task

    1. Preform 1's complement subtraction 110101 – 100101
    2. Represent decimal number 0.125 into its binary form
    5
  3. 6.

    Derive the Boolean expression for sum and carry of half adder. Draw its combinational circuit. Implement it using only NAND gates.

    5
  4. 7.

    Express the Boolean function F = x + yz as product of max-terms.

    5
  5. 8.

    Minimize the Boolean function Boolean function using K-map

    F(A, B, C, D) = Σ(0, 1, 3, 5, 7, 8, 9, 11, 13, 15)

    5
  6. 9.

    What are the practical implementations of up counter? Explain Binary ripple counter.

    5
  7. 10.

    Design a combinational circuit with three inputs and one output. The output is 1 when the binary value of the inputs is an odd number.

    5
  8. 11.

    Differentiate between PLA and PAL. Explain 4-bit magnitude comparator

    5
  9. 12.

    Write short notes on (Any Two)

    1. Negative Logic
    2. CMOS
    3. EBCDIC
    5

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