Annamalai University question paper december 2014 B.Sc. Digital electronics and microprocessor

Annamalai University question paper december 2014
B.Sc. DEGREE EXAMINATION, December 2014
(PHYSICS)
(THIRD YEAR)
(PART-III)
750. DIGITAL ELECTRONICS AND MICROPROCESSOR
Time: Three hours Maximum: 100 marks
 SECTION – A
 Answer any TEN questions
(10×2=20)
 1. Find the decimal equivalent of 2FD16.
2. Define max term.
3. Find the gray code of 11000112.
4. Define Multiplexer.
5. Two bit binary numbers(1011 and 1111) are applied to a 4-bit parallel
adder. The array input is 1. What are the values of the sum and carry
output?
6. How many 1-of-16 decoders are required for decoding a 7-bit binary
number?
7. Define Shift registers.
8. What is a stable state? How many stable states does a flip-flop have?
9. What advantages of synchronous counters have over asynchronous
counters?
10. What is the forest method of A/D conversion?
11. Define the term accuracy of DACs.
12. What would be the conversion time of an eight bit successive
approximation type A/D convertor run by a 10MHZ clock?
13. Draw and specify the completer bit configuration of 8085 flag register.
14. Define op-code and operand.
15. What are the limitations of 8085 MPU?
 SECTION – B
 Answer ALL questions
(5×7=35)
16. a) What are called universal gates? Why they are called so?
(OR)
2
5315
 b) Simplify the following SOP equation using k-map procedure and
realize the simplified equation using AND-OR gates.
Y= A . B . D + A. C . D + A .B.C +A.B. C .D+A B C D
17. a) Explain the function of 2’s complement subtraction with necessary
block diagram.
(OR)
 b) What is a half subtraction? Explain the function of a half
subtractor and also discuss how it can be modified to function as a
full subtractor?
18. a) Draw the block diagram of ring counter and explain.
(OR)
 b) Draw the logical diagram of R-S flip using NAND gates and explain
its truth table.
19. a) Explain the operation of counter type ADC. Discuss its merits and
demerits.
(OR)
 b) Explain the working of a variable resistance network.
20. a) Explain the control signals of 8085 microprocessor in detail.
(OR)
 b) Write an assembly language program to add a series of 8-bit
numbers and store the result as 16 bit in two consecutive memory
locations.
 SECTION – C
 Answer any THREE questions
(3×15=45)
21. State and prove De’ Morgan’s theorem.
22. Explain half adder and full adder with symbol, circuit diagram and truth
table in detail.
23. Explain the working of a 4-bit ripple counter with block diagram.
24. Enumerate the principle of binary ladder method of D/A converter with
completer circuit diagram.
25. With a neat diagram explain the architecture of 8085 microprocessor
along with functions of each block and registers.
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