Question Paper: Logic Design : Question Paper Dec 2014 - Computer Science Engg. (Semester 3) | Visveswaraya Technological University (VTU)
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Logic Design - Dec 2014

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) What are universal gates? Realize $$\left (\overline{(A + B)\cdot \ (\overline{A } +\overline{B})} \right )$$ using only universal gates.(5 marks) 1(b) Discuss the positive and negative logic and list the equivalences in positive and negative logic,(5 marks) 1(c) An asymmetrical signal waveform is high for 2 m sec and low for 3 m sec.find
i) Frequency
ii) Period
iii) Duty cycle high.
(5 marks)
1(d) Explain the structure of VHDL / Verilog program.(5 marks) 2(a) The system has four inputs,the output will be high only when the majority of the inputs are high.Find the following :
i) Give the truth table and simplify by using K -map.
ii) Boolean expression in[sum m and prod M form.]
iii) Implement the simplified equation using NAND NAND gates and NOR - NOR gates.
(10 marks)
2(b) Find essential prime implicants for the Boolean expression by using Quine McClusky method.
$$f(A,B,C,D)-\sum M (1,3,6,7,9,10,12,13,14,15).$$
(10 marks)
3(a) IMPLEMENT THE Boolean function expressed by SOP :
[f(A,B,C,D)-sum - m (1,2,5,6,9,12)] using 3 - to - 1 MUX.
(6 marks)
3(b) Implement a full adder using a 3 - to - 8 decoder.(6 marks) 3(c) Design 7 - segments decoder using PLA.(8 marks) 4(a) Give state transition diagram of SR,D,JK and T Filp - flop.(6 marks) 4(b) With a neat logic diagram and truth table,explain the working of JK Master - slave flip flop along with its implementation using NAND gates.(7 marks) 4(c) Show how a D flip - flop can be converted into JK flip - flop.(7 marks) 5(a) With a neat logic diagram,explain the working of a 4- bit SISO register.(10 marks) 5(b) Design two 4-bit serial Adder.(6 marks) 5(c) Write the verilog code for switched tail counter using "assign" and "always" statement.(4 marks) 6(a) Design synchronous mod -5 UP counter using JK Filp-Flop.(10 marks) 6(b) Explain a 3-bit binary Ripple down counter,give the block diagram,truth table and output waveforms.(10 marks) 7(a) with a neat block diagram,explain Mealy and Moore model.(10 marks) 7(b) Design an asynchronous sequential logic circuit for state transition diagram shown in fig.Q7 (b) (10 marks) 8(a) Explain the R/2R Ladder technique of D/A conversion.(10 marks) 8(b) Explain with neat diagram,single slope A/D converters.(10 marks)

 written 3.3 years ago by Team Ques10 ★ 410