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TOTAL MARKS= 100  TOTAL TIME = 3 Hours

#### PART -A  10x2=20

1. What is meant by weighted and non-weighted coding?
2. Show that the Excess – 3 code is self –complementing
3. Write down the truth table of a half sub tractor
4. Define Combinational circuits
5. What do you mean by encoder?
6. What is PAL? How it differ from PROM and PLA?
7. Draw the state diagram of ‘T’ FF, ‘D’ FF
8. What are Mealy and Moore machines?
9. What is meant by critical race?
10.  How to eliminate the hazard?

#### PART - B  5x16=80

11.a Reduce the following equation using Quine McClucky method of
minimization F (A,B,C,D) = _m(0,1,3,4,5,7,10,13,14,15)
or

b,Find the MSP representation for
F(A,B,C,D,E) = _m(1,4,6,10,20,22,24,26) + _d (0,11,16,27) using K-Map method
Draw the circuit of the minimal expression using only NAND gates

12.a(a) Draw a diode ROM, which translates from BCD 8421 to Excess 3 code

or
Design a combinational circuit which accepts 3 bit binary number and converts its

equivalent excess 3 codes

13.a,Explain the operation of 4 to 10 line decoder with necessary logic diagram
or
b,.Design a combinational circuit using a ROM ,that accepts a 3- bit number and

generates an output binary number equal to the square of the given input number

14,a Design a modulo 5 synchronous counter using JK FF and implement it. Construct its
timing diagram
or
b,Design a binary counter using T flip – flops to count in the following sequences:
(i) 000,001,010,011,100,101,110,111,000
(ii) 000,100,111,010,011,000

15,a Summarize the design procedure for asynchronous sequential circuit
a. Discuss on Hazards and races
b. What do you know on hardware descriptive languages?

or

b.Design an asynchronous sequential circuit with two inputs X and Y and with one output Z.
Whenever Y is 1, input X is transferred to Z.When Y is 0,the output does not change for any change in X