Sathyabama University 2008 B.E Computer Science and Engineering Digital Computer Fundamentals - Question Paper

SATHYABAMA UNIVERSITY

(Established under section 3 of UGC Act, 1956)

 

Course & Branch: B.E - CSE (Part Time)

Title of the paper: Digital Computer Fundamentals

Semester: III Max. Marks: 80

Sub.Code: 611PT301 (2006/2007) Time: 3 Hours

 

PART A (10 x 2 = 20)

Answer All the Questions

 

1. What is the largest binary number that can be expressed with 12 bits? Write the equivalent decimal and hexadecimal values.

2. Define hamming code.

 

3. Simplify the Boolean expression to minimum number of literals.

(i) xy + xy' (ii) ABC + A'B + ABC'

 

4. Show that the dual exclusive OR is equal to its complement.

 

5. What are the steps involved in the design of combinational circuit?

 

6. Define Magnitude Comparator.

 

7. Differentiate between Synchronous and Asynchronous sequential circuit.

 

8. Construct a JK flip flop using D flip flop.

 

9. Write down the different types of ROMs.

 

10. What are optical storage devices? Give example.

PART B (5 x 12 = 60)

Answer All the Questions

 

11. Convert the decimal +61 and +27 to binary using the signed 2s complement representation and enough digits to accommodate the number. Then perform the binary equivalent of (+27) + (-61), (-27) + (+61) (-27) + (-61). Convert the answers back to decimal and verify that they are correct.

(or)

12. Assume a 3 input AND gate with output F and 3 input OR gate with output G. Inputs are A,B and C. Show the signals by means of timing diagrams for the outputs of F and G as function of 3 input ABC. Use all 8 possible combinations.

 

13. Express the following function in sum of min terms and product of max terms.

F (A, B, C, D) = B'D + A'D + BD

(or)

14. Simplify the Boolean expression using Quine McClusky method.

B'D + A'BC' + AB' + ABC'

 

15. Design a 4 bit combinational circuit incrementer. (A circuit that adds one to a 4 bit binary number). The circuit can be designed using 4 half adder.

(or)

16. Design an excess 3 to binary decoder using unused combinations of BCD code as dont care conditions.

 

17. Design a sequential circuit with 2 JK flip flops A & B and two inputs E & x. If E = 0 the circuit remains in the same state regardless of the value of x. When E = 1 and x = 1 the circuit goes through the state transitions from 00 to 01 to 10 to 11 back to 00 and repeats. When E = 1 and x = 0 the circuits goes through the state transitions from 00 to 11 to 10 to 01 back to 00 and repeats.

(or)

18. Explain Binary ripple counter and BCD ripple counter with neat diagrams.

 

19. Explain Random Access Memory with read and write cycles and give the timing diagrams.

(or)

20. Explain in detail about Storage hierarchies.