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.
_______________________
