CSC116 Digital Logic

Digital Logic TU Board 2081 question paper

12 questionsSit this paper (timed)

Tribhuvan University

Bachelor of Science in Computer Science and Information Technology

Semester 1 · TU Board 2081

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

Answer any TWO question.(2 × 10 = 20)

  1. 1.

    Differentiate between synchronous and asynchronous counter. Design a 3-bit synchronous binary counter using T Flip Flop. Draw its timing diagram.

    10
  2. 2.

    Explain De-Morgan's Law. Simplify the Boolean function F(P,Q,R,S) =Π(0,1,4,5,11,14,15) and d(P,Q,R,S) =Σ(2,3,7,8,9,13) using K-Map in both SOP and POS form.

    10
  3. 3.

    Explain design procedure of combinatorial circuits. Design a combinatorial circuit with three inputs x, y, and z, and three outputs A, B, and C. When the binary input is 0, 1, 2 or 3, the binary output is one greater than the input. When the input is 4, 5, 6, or 7, the binary output is one less than the input.

    10

Group B

Answer any EIGHT question.(8 × 5 = 40)

  1. 4.

    Given A=46 and B=35 represent them in binary and perform A-B using 1's complement method.

    5
  2. 5.

    What is Multiplexer. Design 8 to 1 Multiplexer with low level Multiplexers.

    5
  3. 6.

    Write about D flip flop with necessary circuit, block diagram, characteristic table and equation.

    5
  4. 7.

    Simplify F(A, B, C, D) = Σ(1,3,4,6,9,11,12,14) and realize the equation using NOR gates only.

    5
  5. 8.

    Mention different types of shift registers. Explain SIPO with timing diagram.

    5
  6. 9.

    What is decoder? Describe the 3 to 8 line decoder circuit.

    5
  7. 10.

    Explain state diagram, state table, state reduction and state assignment with suitable example.

    5
  8. 11.

    Design a 2 bit asynchronous binary counter using T flip flop. Draw its timing diagram.

    5
  9. 12.

    Write short notes on:

    1. Encoder
    2. Error detection codes
    5

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