SCS9C21-Novermber 2012

SCS9C21                                                                                                          November 2012

DIGITAL PRINCIPLES AND COMPUTER ORGANIZATIONS

(For those who joined in July 2009 and after)

Time : Three hours                                                                                      Maximum : 75 marks

SECTION A – (10 x 1 = 10 marks)

Answer ALL questions.

Choose the correct answer:

11.       A nibble is

(a)    1 bit               (b) 4 bits              (c) 8 bits               (d) 16 bits              Ans.: (b)

22.       The next number of 835C₁₆ is

(a)    8352₁₆           (b) 8350₁₆            (c) 83CD₁₆            (d) 835D₁₆              Ans.: (d)

33.       The distributive law is

(a)    A+B = B+A    (b) A+(B+C)=(A+B)+C      (c) A(B+C)=AB+AC            

(d) A+0=A            Ans.: (b)

44.       A group of four is that are horizontally or vertically adjacent is

(a)    Quad             (b) Tuple             (c) Octal               (d) Pair                  Ans.: (a)              

55.       What is the result of the following binary subtraction? 1101 - 1010

(a)    0010               (b) 0001                (c) 0011                (d) 1001           Ans.: (c)

66.       Which of the following is not a flip-flop?

(a)D       (b) JK     (c) JD     (d) RS                                                                   Ans.: (c)

77.       74164 is

(a)    Serial in parallel out register              (b) Serial in Serial out register   

(c) Parallel in serial out register               (d) Parallel in Parallel out register  Ans.: (c)

88.       How many flip-flop are required to construct a mod 128 counter?

(a)    5      (b) 9       (c) 8                       (d) 7                                                  Ans.: (d)

99.       Computer that have a single processor register usually assign to it the name____________

(a)    Shift register             (b) operands      (c) MBR                               

  (d) Accumulator               Ans.: (d)

110.   The operation of insertion into stack is called.

(a)    Pull                                (b) Push               (c) Pop  (d) Stuff                   Ans..: (b)

SECTION B – (5 x 7 = 35 marks)

Answer ALL questions, choosing either (a) or (b)

111.   (a)Explain octal to decimal and octal to binary conversion with examples.

Or

(b)   Draw the logic circuit for the Boolean equation Y=ᾹBC + AB/C + ABC/

112.   (a)Draw a NOR-NOR circuit for the Boolean equation

Y = ( A + B + C) (A + B + C) (A + B + C)

Or

(b)   Explain BCD to Decimal decoders.

113.   (a) Perform 2’s Complement addition with suitable example.

Or

(b)Explain Edge triggered RS flip-flop.

114.   (a) Explain parallel in parallel out shift registers.

Or

(b)   Write a note on Ripple counters.

115.   (a) Describe the Data manipulation Instructions.

Or

                (b)Write a note on Control memory.

SECTION C – (3 x 10 = 30 marks)

Answer any THREE questions.

116.   Explain the Excess-3 code and Gray code.

117.   What is the simplified Boolean equation for Y = F (A,B,C,D) = Σ m(1,2,3,6,8,9,10,12,13,14)

118.   Explain Half adder and full adder.

119.   Discuss on Application of Shift Registers.

220.   Illustrate with example, the different instruction formats.

_______________________