III/BCA/305 Student's Copy
Professional Course Examination, November 2018
3rd Semester
BACHELOR OF COMPUTER APPLICATIONS
Course BCA-305
Computer Organization and Architecture
Revised
Full Marks 75
Time 3 hours
PART A—OBJECTIVE
Marks 25
The figures in the margin indicate full marks for the questions
SECTION—A
Marks 15
Tick the correct answer in the brackets provided 1×10=10
1. Which shift microoperation multiples a signed binary number by
shl
shr
ashl
ashr
/370 1 Contd.
2. If R =1011, then R R is
0100
1100
0110
0101
3. Which of the following registers has 12 bits?
AR
IR
TR
INPR
4. Instruction to increment and skip if zero is
INC
SKI
ISZ
Both and
III/BCA/305 2 Contd.
5. Stack organization employs
LIFO
FIFO
LILO
FILO
6. Which of the following is zero-address instruction?
MUL R1
ADD B
MOV R1, A
PUSH A
7. Command used to test various status conditions is
interrupt
I/O
control
status
III/BCA/305 3 Contd.
8. The DMA transfers are performed by a control circuit called as
device interface
DMA controller
data controller
overlooker
9. The surrounding of the recently accessed block is called as
neighbourhood
neighbour
locality of reference
None of the above
10. The counter that keeps track of how many times a block is most likely
used is
count
reference counter
use counter
probable counter
III/BCA/305 4 Contd.
Indicate whether the following statements are True or False by putting
a Tick mark in the brackets provided 1×5=5
1. The high-impedance state behaves like an open circuit.
T F
2. Hardwired control is faster than microprogrammed control.
T F
3. RISC has variable length instruction format.
T F
4. Interrupt is used to break the ongoing process of CPU.
T F
5. The DMA doesn't make use of the MMU for bulk data transfers.
T F
SECTION—B
Marks 10
Answer the following questions 2×5=10
1. Explain memory transfer.
2. What is accumulator
3. Write a note on Program Counter.
4. What is DMA?
5. How is data stored in a magnetic disk?
III/BCA/305 5 Contd.
PART B—DESCRIPTIVE
Marks 50
The figures in the margin indicate full marks for the questions
1. Design a common bus system for four registers using 4×1 multiplexers
and explain how it works. 6
What are the basic arithmetic microoperations? Describe the symbolic
designation of microoperations. 4
OR
What is binary adder? Construct a circuit diagram for 4-bit binary
adder-subtractor using full adder. 5
What is a logic microoperation? Give a list of sixteen logic microoperations
with their corresponding Boolean functions. 5
2. What is computer register? List out registers for the basic computer
and briefly explain their functions. 5
What is a computer instruction? Briefly explain any eight basic
computer instructions. 5
OR
Explain four phases of an instruction cycle. 4
Briefly explain machine language, assembler and subroutines. 6
3. What are the major components of CPU? Explain how CPU bus system
directs information flow to perform operation R1 R2 R3. 6
Write a note on stack organization. 4
III/BCA/305 6 Contd.
OR
Describe any four addressing modes. 6
What are the three basic types of data manipulation instructions? Give
a list of shift instructions. 4
4. What do you mean by interface? Explain the connection of I/O bus to
input-output devices using diagram. 6
Explain strobe and handshaking for asynchronous data transfer giving
suitable diagram. 4
OR
Discuss the three modes of transfer to and from peripherals. 6
What is IOP? Write a block diagram of a computer with I/O processor. 4
5. What do you mean by memory? Explain the hierarchy of memory
giving diagrams. 4
What is main memory? Explain the functions of RAM and ROM. 6
OR
Write a note on virtual memory. 5
What is cache memory? What are the three types of mapping
procedure? 5