EE2255 DIGITAL LOGIC CIRCUITS NOV/DEC 2010 ANNA UNIVERSITY PREVIOUS YEAR QUESTION PAPER, IMPORTANT QUESTIONS, 2 MARKS AND 16 MARKS QUESTIONS FOR EEE DEPARTMENT

EE 2255 DIGITAL LOGIC CIRCUITS NOV/DEC 2010 ANNA UNIVERSITY PREVIOUS YEAR QUESTION PAPER, IMPORTANT QUESTIONS, 2 MARKS AND 16 MARKS QUESTIONS FOR EEE DEPARTMENT

ANNA UNIVERSITY PREVIOUS YEAR QUESTION PAPER EE2255 DIGITAL LOGIC CIRCUITS NOV/DEC 2010 , IMPORTANT QUESTIONS, 2 MARKS AND 16 MARKS QUESTIONS FOR EEE DEPARTMENT

B.E./B.Tech. DEGREE EXAMINATION, NOVEMBER/DECEMBER 2010

Fourth Semester

Electrical and Electronics Engineering

EE 2255 — DIGITAL LOGIC CIRCUITS

(Regulation 2008)

Time : Three hours Maximum : 100 Marks

Answer ALL questions

PART A — (10 × 2 = 20 Marks)

1. Show that Excess-3 code is self complementing.
2. Add the hexadecimal numbers: 93 and DE.
3. Convert JK flip-flop to T-flip-flop.
4. Mention the major application of Master Slave FF.
5. Draw the state diagram of SR Flip Flop.
6. Define asynchronous sequential machine.
7. State the important characteristics of TTL family.
8. In which type of TTL gate wired ANS logic is possible?
9. Write the VHDL code for AND gate.
10. List the operators available in VHDL.
PART B — (5 × 16 = 80 Marks)
11. (a) Reduce the following using tabulation method and verify with K maps.
( ) ( ) ∑ = 14 , 12 , 10 , 8 , 6 , 4 , 3 , 2 , 1 , 0 , , , D C B A F
Or
(b) Obtain the minimum SOP using Quine Mcclusky’s method and verify
using ‘K’ map for the following.
13 12 11 10 9 8 4 2 0
m m m m m m m m m F + + + + + + + + = .
12. (a) Design a counter with the sequence 0, 1, 3, 7, 6, 4, 0.
Or
(b) The following sequence is to be realized by a counter consisting of
3 JKFF’s.
A1 0 0 0 0 1 1 0
A2 0 1 1 0 0 1 0
A3 0 1 0 1 1 0 0
Design the counter.
13. (a) (i) List and explain the steps used for analyzing an asynchronous
sequential circuit. (8)
(ii) Describe procedure to get state table from excitation table in an
asynchronous sequential circuit. How does it differ from
synchronous sequential circuit? (8)
Or
(b) (i) How do you get output specifications from a flow table in
asynchronous sequential circuit operating in fundamental mode? (6)
(ii) When do you get the critical and non-critical races? How will you
obtain race free conditions? (10)
14. (a) (i) Explain the concept, working and characteristics of TTL logic
families. (8)
(ii) What do you understand by FPGA? Explain the operation and
applications? (8)
Or
(b) (i) Describe the working of EPROM. List the applications of EPROM.
(8)
(ii) Discuss on the concept, operation and characteristics of CMOS
technology. (8)
15. (a) Construct a VHDL module listing for a 16:1 MUX that is based on the
assign statement. Use a 4-bit select word S3 S2 S1 S0 to map the selected
input Pi (i = 0,...15) to the output.
Or
(b) (i) Explain the design procedure of RTL using VHDL. (10)
(ii) Write a note on VHDL test benches. (6)