Computer Science and Information Technology - Computer Organization and Architecture
Exam Duration: 45 Mins Total Questions : 30
In 2's complement rep[resentation, if two numbers with the same sign are added, then
- (a)
overflow occur if and only if the result has the opposite sign
- (b)
overflow occur if and only if the result has same sign
- (c)
overflow does not occur
- (d)
Both (a) and (b)
The booth algorithm
(1) generates a 2n-bit product.
(2) treats both positive and negative 2's complements n-bit operand uniformly.
- (a)
1
- (b)
1, 2
- (c)
2
- (d)
Neither (1) nor (2)
The addressing mode in an instruction of the form ADD 05, 06 is
- (a)
absolute
- (b)
immediate
- (c)
indirect
- (d)
index
Which of the following is direct addressing instruction?
- (a)
MOV A, B
- (b)
MOV B, OAH
- (c)
MIOV C, M
- (d)
STA address
Programming that actually controls the path of the data within the computer called
- (a)
micro programming
- (b)
system programming
- (c)
assemble language
- (d)
machine language programming
Linkage between CPU and the user is procided by
- (a)
peripheral devices
- (b)
control unit
- (c)
storage
- (d)
software
An interrupt can be temporarily ignored by the counter is called
- (a)
vectored interrupt
- (b)
non-maskable interrupt
- (c)
maskable interrupt
- (d)
low priority interrupt
Microprogram is
- (a)
the name of source program in micro computers
- (b)
the set of instructions indicating the primitive operations in a system
- (c)
primitive form of macros used in assembly language programming
- (d)
program of very small size
Whihc of the following is the internal memory of the system?
- (a)
CPU register
- (b)
CAche
- (c)
Main memory
- (d)
All of these
Interrupt driven I/O
- (a)
has its main drawback in the software overhead of interrupts
- (b)
may be better than busy waiting I/O since, less hardware support is required.
- (c)
is equal or faster than DMA for a signal word register
- (d)
Both (a) and (c)
The data transfar in which data transfar is to be done quckly
- (a)
programmed I/O
- (b)
Interrupt I/O
- (c)
DMA
- (d)
None of these
The correct matching for following pair is
a. DMA I/O | 1. High speed DMA |
b. Cache | 2. Disk |
c. Interrupt | 3. Printer |
d. Condition code register | 4. ALU |
- (a)
a-4, b-3, c-1, d-2
- (b)
a-2, b-1, c-3, d-4
- (c)
a-4, b-3, c-2, d-1
- (d)
a-2, b-3, c-4, d-1
Comparing the time T1 taken for a single instruction on a pipelined CPU with time T2 taken on a non-pipelined but identical CPU, we can say that
- (a)
\({ T }_{ 1 }\le { T }_{ 2 }\)
- (b)
\({ T }_{ 1 }\ge { T }_{ 2 }\)
- (c)
\({ T }_{ 1 }<{ T }_{ 2 }\)
- (d)
\({ T }_{ 1 }{ isT }_{ 2 }\) plus line taken for one instruction fetch cycle
A 4-stage pipeline has the stage delays as 150, 120, 160 and 140 ns respectively. Registers that are used between the stages have a delay of 5 ns. Assuming comstant locking rate the total time required to process 1000 data items on this pipeline is
- (a)
165.5 \(\mu s\)
- (b)
120.5 \(\mu s\)
- (c)
160.5 \(\mu s\)
- (d)
590.5 \(\mu s\)
How many 32kx1 RAM chips are needed to provide a memory capacity of 256 kb?
- (a)
8
- (b)
32
- (c)
64
- (d)
128
Search concept in associative memory is
- (a)
parallel search
- (b)
sequential search
- (c)
binary search
- (d)
selection search
Tag bits in direct mapping can be given by
- (a)
log2m
- (b)
log2(m/n)
- (c)
log2n
- (d)
log2mn
I/O device cannot be connected directly to the system because of
- (a)
speed mismatch
- (b)
different data formats
- (c)
Both (a) and (b)
- (d)
None of these
Advantages of DMA over software transfer are
- (a)
tack of software overhead from loop-control instructions.
- (b)
that it leaves the bus free for the CPU to access main memory.
- (c)
that it combines multiple interrupt into one
- (d)
both (a) and (c)
Which of the following statementsis incorrect about Program Counter (PC)?
I. PC does not affect instruction sequencing.
II. During branchu operation, prgram counter points to the memory from which instruction is to be fetched and executed.
III. The program counter contents are used as address and instruction is read from memory.
- (a)
I only
- (b)
II only
- (c)
Both I and II
- (d)
Neither I nor II
Which of the following statements is correct about the program counter?
I. Program counter points to the instruction to be executed .
II.The program counter contents are used as address and instruction is read from memory.
- (a)
I only
- (b)
II only
- (c)
I and II
- (d)
Neither I nor II
Match List I with List II abd select the correct answer using the codes given below the lists.
List I | List II |
A. 0-address instruction | 1. T=TOP(T-1) |
B. 1-address instruction | 2. Y=Y+x |
C. 2-address instruction | 3. Y=A-B |
D. 3-address instruction | 4. ACC=ACC-X |
- (a)
A B C D 1 2 3 4 - (b)
A B C D 3 2 4 1 - (c)
A B C D 2 3 1 4 - (d)
A B C D 1 4 2 3
Match the following number system:
Number system | Range |
A. Signed magnitude | 1. 0-2n-1 |
B. 1's complemeny | 2. (-2n-1) + 0 to (2n-1-1) |
C. 2's complement | 3. (-2n-1) to (2n-2-1) |
- (a)
A-3, B-3, C-1
- (b)
A-1, B-2, C-3
- (c)
A-2, B-1, C-3
- (d)
None of these
Stack pointer is affected by
- (a)
1 and 2
- (b)
1 and 3
- (c)
2 and 3
- (d)
1, 2 and 3
What is the hit ratio of cache, if a system performs memory access at 300 ns with the cache and 150 ns without it? Assume that the average access time of memory is 42 ns.
- (a)
81%
- (b)
75%
- (c)
92%
- (d)
87%
A cache memory needs an access time of 20 ns and main memry 120 ns, what is the average access time of CPU (assume hit ratio= 80%)?
- (a)
30 ns
- (b)
44 ns
- (c)
35 ns
- (d)
45 ns
Which of the following devices is havng a highest priority while assigning interrupts?
- (a)
Hard disk
- (b)
Printer
- (c)
Keyboard
- (d)
Floppy
Which of the following is not an advantage of virual memory?
- (a)
Faster access to memory on an average
- (b)
Process can be gicven protected address space
- (c)
Linker can assign address independent of where the program will be loaded in main memory.
- (d)
Program larger than physical memory size can be run
An address space is specified by 24-bit and the correspondence memory space is 16 bit.
How many words are there in memory space?
- (a)
16 m words
- (b)
64 k words
- (c)
4 k words
- (d)
4 m words
A memory stores 6k of 16-bit words.Number of data input/output lines, it has
- (a)
17
- (b)
15
- (c)
12
- (d)
12