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.

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SCS8C21-Novermber 2012

SCS8C21                                                                                                                 November 2012

DIGITAL PRINCIPLES AND COMPUTER ORGANIZATIONS

(For those who joined in July 2008 and after)

Time : Three hours                                                                                       Maximum : 75 marks

SECTION A – (10 x 1 = 10 marks)

Answer ALL questions.

Choose the correct answer:

11.       The __________ is an alpha numeric code widely used for transforming data into and out of a computer.

(a)    Octal              (b) Hexadecimal               (c) ASCII               (d) Binary         Ans.: (c)

22.       A __________ is a group of four 1’s that are horizontally or vertically adjacent.

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

33.       ___________ is a universal logic circuit because it can generate any truth table.

(a)    BCD decorder            (b) Multiplexer (c) Decoder        (d) Encoder           Ans.: (a)

44.       __________ gates are ideal for checking the parity of a binary number.

(a)    NOR               (b) NAND            (c) OR    (d) EX-OR                               Ans.: (d)              

55.       A group of flip-flops sensitive to pulse transition is called as

(a)    Register       (b) Counter        (c) Multiplexer  (d) Interrupt                     Ans.: (b)

66.       The D flip-flop is a modification of

(a) RS flip-flop   (b) RS clocked flip-flop   (c) JK flip-flop    (d) JK master slave flip-flop      Ans.: (c)

77.       The operations of a stack are stimulated by incrementing or decrementing the

(a)    Stack limit register   (b) Stack point register  (c) Random access memory       

(d) All the above                                                                                Ans.: (b)

88.       _________ address instruction are the most common in commercial computers.

(a)    Two               (b) Three             (c) Zero                                (d) One         Ans.: (c)

99.       The ______________ method of asynchronous data transfer employs a single control line to time.

(a)    Hand shaking             (b) Strobe control            (c) FIFO buffer  (d) DMA     Ans.: (d)

110.   Devices that provide backup storage with CPU is called

(a)    Main memory           (b) Auxiliary memory     (c) Memory hierarchy    

(d) Associative memory                                                                    Ans..: (b)

SECTION B – (5 x 7 = 35 marks)

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

111.   (a) Convert Grey number 1011 to bits BCD equivalent.

Or

(b)   State and prove De Morgan’s theorem.

112.   (a) Explain BCD to decimal decoder.

Or

(b)   Explain binary subtraction using 2’s compliment.

113.   (a) Describe the working of a ring counter.

Or

(b)Explain D-flip-flop with diagram.

114.   (a) Explain the indirect cycle of the computer cycle control.

Or

(b)   Discuss the various POP operations in stack.

115.   (a) Explain the various commands received by an interface.

Or

                (b)Describe the associative mapping in Cache memory.

SECTION C – (3 x 10 = 30 marks)

Answer any THREE questions.

116.   Convert (BEEF)₁₆ into binary, Octal and decimal numbers.

117.   Explain the function of a multiplexer.

118.   Explain a serial-in-control-out shift register.

119.   Explain the need and use of DI and EI instructions.

220.   With a block diagram, explain the parallel peripheral interface.

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