Digital Logic
This course introduces the basic tools for the design of digital circuits and introducing methods and procedures suitable for a variety of digital design applications.
Tribhuvan University
Institute of Science and Technology
2081
Bachelor Level / first-semester / Science
Computer Science and Information Technology( CSC116 )
Digital Logic
Full Marks: 60 + 20 + 20
Pass Marks: 24 + 8 + 8
Time: 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.
SECTION A
Answer any TWO question.
Differentiate between synchronous and asynchronous counter. Design a 3-bit synchronous binary counter using T Flip Flop. Draw its timing diagram.
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.
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.
SECTION B
Answer any EIGHT question.
Given A=46 and B=35 represent them in binary and perform A-B using 1’s complement method.
What is Multiplexer. Design 8 to 1 Multiplexer with low level Multiplexers.
Write about D flip flop with necessary circuit, block diagram, characteristic table and equation.
Simplify F(A, B, C, D) = Σ(1,3,4,6,9,11,12,14) and realize the equation using NOR gates only.
Mention different types of shift registers. Explain SIPO with timing diagram.
What is decoder? Describe the 3 to 8 line decoder circuit.
Explain state diagram, state table, state reduction and state assignment with suitable example.
Design a 2 bit asynchronous binary counter using T flip flop. Draw its timing diagram.
Write short notes on:
- Encoder
- Error detection codes