Download AKTU (Dr. A.P.J. Abdul Kalam Technical University (AKTU), formerly Uttar Pradesh Technical University (UPTU) B-Tech 3rd Semester (Third Semester) 2016-2017 NEC 309 Digital Logic Design Question Paper
(Following Paper ID and Roll No. to be ?lled in your
Paper ll) : 2289954
Answer Books)
Roll No. I
B.TECH.
Regular Theory Examination (Odd Sem - III),2016-17
DIGITAL LOGIC DESIGN
Time : 3 Hours Max. Marks : 100
Note: Attempt All sections. If require any missing data: then
choose suitably.
Section - A
1. Attempt all questions in brief. (10X2=20)
a) Perform 2?s complement Subtraction of 0101 10-
100101.
b) What is the feature of gray code?
c) Write the logic equation and draw the internal logic
diagram for a 4 to 1 mux.
d) What is a priority encoder?
6) List the major differences between PLA and PAL.
309/12/2016/15680 ' (1) [93.0.
g)
h)
j)
Attempt any three of the following:
a)
b)
N EC - 309
De?ne a Bus. What are the different types of buses?
Give the comparison between combinational
circuits and sequential circuits.
What are the different types of ?ip-?op?
Give the comparison between synchronous &
asynchronous sequential circuits.
When does race condition occur?
Section - B
(3 x 10=30)
Reduce the Boolean function using k?map technique
and implement using gates
f(w,x,y,z)=2m( (0,1,4,8,9,10)) which has the
2m 211
Implement the following multiple output
combinational logic circuit using a 3 t0 8 decoder.
don? tcares condition d( (w x, y,z
i) f1 =Zm(l,2,3,5,7)
309/12/2016/15680 (2)
d)
NEC - 309
ii) f2 =Zm(0,3,6)
iii) f3 =Zm(0,2,4,6)
What is Ram? Explain the different types of RAM
in detail.
Realize
i) A JK ?ip ?op using SR ?ip ?op.
ii) A SR ?ip ?op using NAND gates and explain
its operation.
Section - C
3 Attempt any one part of the following (1 X 10=10)
a) Detect and correct error (if any) in the following
received even parity Hamming code word
00111101010.
b) Minimize the given Boolean function using Quine
Mc Clusky method
f(A,B,C,D) = Z m(0,1,2,4,5,8,9,11,15) and
implement the simpli?ed function using NOR gates
only.
309/12/2016/15680 (3) [P.T.O.
N EC - 309
4. Attempt any one. part of the following (1 X 10=10)?
a) i) Obtain the simpli?ed Boolean expression for
the output F and G in terms of the input
variables in the circuit of ?g. 1
Fig. 1
ii) Implement the full adder and full subtractor
using decoder.
b) i) Design a combinational circuit that compares
the magnitude of two 3 bit numbers and its
output indicates whether A>B, A = B, A
with a 4 bit adder. What must be done to
change the circuit to an excess 3 t0 BCD code
converter?
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NEC - 309
Attempt any one part of the following (1 X 10=10)
a) Design a combinatipnal circuit using a ROM. The
circuit accepts a three-bit number and outputs a
binary number equal to the square of the input
number.
b) Draw a PLA circuit to implement the functions
f, = A'B+AC?+ A?BC?, f2 =(AC+AB+BC)' ,
f, = BC+ AC+ A'BC?
Attempt any one part of the following (1X10=10)
a) A sequential circuit has three ?ip ?op AB and C;
one input x in and one output y out. The state diagram
is shown in ?g2. The circuit is to be designed by
treating the unused states as don?t?care conditions.
Use T ?ip ?op in the design.
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NEC - 309
b) Design a 4 bit binary synchronous counter with D
?ips ?op.
7. Attempt any one part of the following (1 ><10=10)
a) Derive the transition table for the asynchronous
sequential circuit shown in ?g.3 determine the
sequence of internal states Yle for the following
sequence ofinputXIX2: 00,10;,11,01,11,10,00.
x1?.
1?
3
i L.._._.w.-,...._m._l
,? .____._?_5
9? 1 D 1 ?y2
Fig.3
b) An asynchronous sequential circuit is described by
the excitation function
Y=xlx? +(xl +x;)y and z=y
NEC - 309
i) Draw the logic diagram of the circuit
ii) Drive the transition table and output map.
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This post was last modified on 29 January 2020