Logic Design - Jun 2015

Computer Science Engg. (Semester 3)

TOTAL MARKS: 100
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any four from the remaining questions.
(3) Assume data wherever required.
(4) Figures to the right indicate full marks. 1 (a) Define: i) Rise time
ii) Fall time
iii) Period and
iv) Frequency.(8 marks) 1 (b) What is an universal gate? List the universal gates and prove their universalities.(6 marks) 1 (c) Write the Verilog code for the circuit given below. (6 marks) 2 (a) Using K-map find the reduced SOP form of
f(A, B, C, D) = ∑M(5, 6, 12, 13) + ∑d (4, 9, 14, 15)(5 marks) 2 (b) What is a hazard? List the types of hazards and explain static-0 and static-1 hazards.(5 marks) 2 (c) Simplify the following using Mc-Cluskey method.
F=∑M (0,1, 2, 8, 10, 11, 14, 15).(10 marks) 3 (a) Implement the following function using a 8:1 multiplexer:
f(a, b, c, d) = ∑M(0, 1, 5, 6, 8, 10, 12, 15).(8 marks) 3 (b) Realize the following function using the 3:8 decoder
F₁(A, B, C) = ∑M (1, 2, 3, 4), F₂(A, B, C) = ∑M(3, 5, 7).(6 marks) 3 (c) What is a magnitude comparator? Explain with a neat block diagram an n-bit magnitude comparator.(6 marks) 4 (a) With a neat block diagram, explain the working of a Master-Slave JK flip flop. Also write its truth table.(10 marks) 4 (b) Define: i) Flip flop ii) Hold time iii) Set up time iv) Characteristics equation.(4 marks) 4 (c) Calculate the block cycle time for a system that uses a clock, that has a frequency of
i) 10 Mhz
ii) 50 Mhz
iii) 750 Khz(6 marks) 5 (a) Draw the logic diagram of a 4-bit serial out shift register using J-K flip flop and explain.(8 marks) 5 (b) Explain briefly serial adder with a neat sketch.(8 marks) 5 (c) Write a Verilog code for switched tail counter.(4 marks) 6 (a) Briefly explain 3-bit binary ripple up-counter. Also write the truth table and waveform.(10 marks) 6 (b) Design a Modulo-5 up counter (synchronous) using j-k flip flop.(10 marks) 7 (a) With neat block diagrams compare Mealy Model and Moore model of sequential logic system.(8 marks) 7 (b) Draw the ASM chart for vending machine problem using Mealy model.(12 marks) 8 (a) Explain the concept of 'Successive approximation' of a A/D converter.(10 marks) 8 (b) Draw a binary ladder network for a digital input 1000 and obtain its equivalent circuit.(10 marks)