Model Question Paper
Third Semester B.E. (CBCS) Examination
Digital System Design(17EE35)
Time: 3 Hrs Max.Marks: 100
Note: Answer any FIVE full questions, choosing at least ONE question
from each module
Module-I
1. a. Explain canonical minterm canonical maxterm form with example. (06 Marks)
b. Reduce the following function using K-map technique and implement using basic
gates.

ii) (08 Marks)
c. Design a combinational logic circuit with three input variables that will produce
logic 1 output when more than one input variables are logic 1. (06 Marks)
2. a. Find the reduced POS form of the following equation also implement using
NAND logic. (08 Marks)
b. Find all prime implicants of the function using a Quine-McCluskey method.
(12 Marks)
Module-II
3. a. Implement the following multiple output function using one 74138 external
gates. (06 Marks)
b. Write the compressed truth table for a 4 to 2 line priority encoder with a valid output where
the highest priority is given to highest bit position and simplify the same using K-map. Design
the logic circuit as well. (07 Marks)
c. Design a full adder by constructing the truth table and simplify the output equations.
(07 Marks)
4. a. Design one-bit comparator circuit, represent truth table, k-maps and logic diagram.
(06 Marks)
b. Implement 4-bit parallel adder/subtractor using 4-full adders blocks. Explain its operation, if
Cin 0 the circuit should act as adder and if Cin 1 the circuit act as subtractor. (08 Marks)
c. Implement the function using 8:1 MUX, (06 Marks)
Module-III
5. a. With logic diagram and truth table explain the operation of a SR latch. (06 Marks)
b. Explain the working of a master-slave JK flip-flop with the help of logic diagram,
function table, logic symbol and timing diagram. (08 Marks)
c. With a neat logic diagram, explain the operation of the 4-bit SISO unidirectional
shift resister. (06 Marks)
6. a. Obtain the characteristic equation for D and T flip-flop. (04 Marks)
b. Explain the working principle of four bit binary ripple counter, with the help of logic
diagram and timing diagram . (06 Marks)
c. Design a synchronous counter Mod-6 Using clocked D flip-flops. (10 Marks)
Module-IV
7. a. Design a synchronous counter to sequence Using clocked D flipflops.
(10 Marks)
b. Analyze the following synchronous sequential circuit. (10 Marks)
8. a. Explain Mealy and Moore model with neat block diagram. (08 Marks)
b. Realize the system represented by the following state diagram using D flip-flop.
(12 Marks)
Module-V
9. a. Explain brief history of HDL and Structure of HDL module. (08 Marks)
b. List the various styles/types of descriptions. Explain VHDL Behavioral description
with example code. (12 Marks)
10. a. Mention types of VHDL operators. Explain in detail any one operator. (06 Marks)
b. Compare VHDL and verilog. (08 Marks)
c. Explain the signal declaration and signal assignment statements with relevant
example (06 Marks)