A4-R3: COMPUTER ORGANIZATION
: JANUARY 2005
NOTE:
1. There are TWO PARTS in this Module/paper. PART ONE contains FOUR questions and PART TWO contains FOUR questions.
2. PART ONE is to be answered in the TEAR-OFFANSWER SHEET only, attached to the question paper, as per the instructions contained therein. PART ONE is NOT to be answered in the answer book.
3. Maximum time allotted for PART ONE is ONE HOUR. Answer book for PART TWO will be supplied at the table when the answer sheet for PART ONE is returned. However, candidates who complete PART ONE earlier than one hour, can collect the answer book for PART TWO immediately after handing over the answer sheet for PART ONE.
TOTAL TIME: 3 HOURS TOTAL MARKS: 100
(PART ONE-40; PART TWO – 60)
PART ONE
(Answer all the questions)
1. Each question below gives a multiple choice of answers. Choose the most appropriate one and enter in the “tear-off” answer sheet attached to the question paper, following instructions therein. (1 x 10)
1.1 A Toggle flip-flop can be constructed using a JK flip-flop by connecting the
A) toggle input to J and the inverted from of toggle input to K.
B) the toggle input to J
C) inverted form of toggle input to K.
D) None of the above
1.2 The number of select input lines in an 8-to-1 multiplexer is
A) 1
B) 8
C) 256
D) None of the above
1.3 CARRY, in half adder, can be obtained using
A) EX - OR gate
B) AND gate
C) OR – gate
D) EX - NOR gate
1.4 Booth algorithm gives procedure for multiplying binary integers in
A) signed magnitude representation
B) unsigned representation
C) 2’s complement representation
D) None of the above
1.5 a memory device, in which a bit is stored as a charge across the stray capacitance
A) SRAM
B) EPROM
C) DRAM
D) bubble memory
1.6 Fetch operations are not required in
A) Direct addressing
B) immediate addressing
C) indirect addressing
D) register addressing
1.7 A debugging tool is a program which
A) removes bugs from user program
B) removes viruses from the computer
C) helps the user find bugs in his program
D) displays the errors in a user program
1.8 A diamond-shaped box in a flow chard refers to
A) An assignment statement
B) printing of a file
C) an if – then – else decision
D) data input from a device
1.9 In the difference between a COMPARE instruction and a SUBTRACT instruction is
A) COMPARE instruction does not set any flags
B) SUBTRACT instruction does not set any flags
C) COMPARE leaves the registers unchanged
D) COMPARE instruction does not require the ALU
1.10 In the IEEE 754 floating point representation standard, the base is
A) 23
B) 127
C) 16
D) None of the above
2. Each statement below is either TRUE or FALSE. Choose the most appropriate one and ENTER in the “tear-off” sheet attached to the question paper, following instructions therein. (1 x 10)
2.1 When the multiplier is 01 (decimal), Booth’s multiplication algorithm requires one addition and one subtraction.
2.2 A queue is a first –in first – out structure
2.3 When a right shift operation is performed on two’s complement numbers, zeros must be shifted from the left.
2.4 A software interrupt is an instruction executed by the CPU.
2.5 An instruction cycle always consists of one memory read operation.
2.6 PUSH is a zero-address instruction.
2.7 In Boolean algebra Wx+ yx + Wy can be reduced to Wx+ yx.
2.8 Decoding on instruction takes place in several steps of the execution phase.
2.9 The set of microinstructions are stored in RAM.
2.10 An astable multivibrator can be used as flip-flop.
3. Match words and phrases in column X with the closest related meaning/ word(s)/phrases in column Y. Enter your selection in the “tear-off” answer sheet attached to the question paper, following instructions therein. (1 x 10)
X Y
3.1 Segment registers A. Immediate addressing
3.2 Cache memory B. Micro-controller
3.3 (ab)' = a' + b' C. NOP
3.4 A single chip computer D. Master/slave JK – Flip-flop
3.5 An instruction to provide small delays E. 8086 CPU
3.6 Hamming code F. Hard Copy
3.7 Seek time G. RAM
3.8 LRU H. Error detecting and correcting code
3.9 Address is an operand I. Page replacement policy
3.10 Racing problems do not exist J. De-Morgan's theorem
K. Locality of reference
L. Hard disk reference
4. Each statement below has blank space to fit one of the word(s) or phrases in the list below. Enter your choice in the “tear-off” answer sheet attached to the question paper, following instructions therein. (1 x 10)
A. Faster B. I/O Mapped I/O C. Harvard
D. X E. Assembly F. Dirty
G. -128 H. Hamming distance I. -256
J. Logical AND K. I/O Pins L. Hamiltonian distance
M. 16
4.1 Y is the two’s complement of a number X. The two complement of Y will give us _______.
4.2 The smallest negative integer that can be represented in 8-bit two’s complement notation is _______.
4.3 The _______ bit is used in a write back cache to avoid unnecessary updates of main memory pages.
4.4 A hardwired control unit is _______, when compared to a micro-programmed control unit.
4.5 Address lines and data lines are sometimes multiplexed in order to restrict the _______.
4.6 The kernel of an operating system is likely to be written in _______ language of the underlying processor in order to improve the performance.
4.7 In a grey code sequence, the _______ between any two successive numbers is 1.
4.8 The number of 256 x 4 RAM chips required to contract a 2KB cache is _______.
4.9 When input/ output is performed, using instructions such as IN and OUT which are meant for I/O devices, the mapping scheme used is called _______.
4.10 A digital computer, in which data memory is separated from instruction memory, is said to have _______ architecture. For more questions papers visit www.DoeaccOnline.com, www.IgnouOnline.com
PART TWO
(Answer ALL questions)
5.
a) Show, how cache memory may be organized in a computer?
b) Explain the need of memory hierarchy. What is the main reason for not having a large main memory for storing the totality of information in a computer system?
(6+9)
6.
a) When we write an assembly language program, what are the three essential columns that we include in every line? Explain the significance of each of these.
b) Write and explain an assembly language program to subtract two numbers.
c) What is meant by a macro? Compare the relative merits and demerits of using macros instead of subroutines in a program
(5+5+5)
7.
a) Explain the difference between combinational and sequential logic.
b) Explain how a JK flip-flop can be realized from a R-S flip-flop? What is Toggle flip-flop?
c) What is the difference between zero – address, one – address and two address instructions? Illustrate with the help of examples.
(4+4+7)
8.
a) What is microinstruction? Distinguish between horizontal and vertical microinstructions.
b) Explain the organization of control memory. How is control unit implemented using control memory?
c) What is the difference between direct-address and indirect address mode? Explain relative and base – register addressing.
(4+6+5)
