MCQ Vlsi 1
MCQ Vlsi 1
MCQ Vlsi 1
17) Which type of digital systems exhibit the necessity for the existence of at least one
feedback path from output to input?
a. Combinational System
b. Sequential system
c. Both a and b
d. None of the above
ANSWER: Sequential system
18) The output of sequential circuit is regarded as a function of time sequence of __________.
A. Inputs
B. Outputs
C. Internal States
D. External States
a. A & D
b. A & C
c. B & D
d. B & C
ANSWER: A & C
19) The time required for an input data to settle _____ the triggering edge of clock is known
as Setup Time.
a. Before
b. During
c. After
d. All of the above
ANSWER: Before
20) Hold time is defined as the time required for the data to ________ after the triggering
edge of clock.
a. Increase
b. Decrease
c. Remain stable
d. All of the above
ANSWER: Remain stable
21) An Antifuse programming technology is predominantly associated with _____.
a. SPLDs
b. FPGAs
c. CPLDs
d. All of the above
ANSWER: FPGAs
22) In fusible link technologies, the undesired fuses are removed by the pulse application
of _____voltage & current to device input.
a. Low
b. Moderate
c. High
d. All of the above
ANSWER: High
23) Which programming technology/ies is/are predominantly associated with SPLDs and
CPLDs?
a. EPROM
b. EEPROM
c. FLASH
d. All of the above
ANSWER: All of the above
24) Before the commencement of design, the clocking strategy determine/s __________
a. Number of clock signals necessary for routing throughout the chip
b. Number of transistors used per storage requirement
c. Power dissipated by chip & the size of chip
d. All of the above
ANSWER: All of the above
25) Which method/s of physical clocking is/are a /the recursive structure where the
memory elements are grouped together to make the use of nearby or same distribution
points?
a. H tree
b. Balanced tree clock network
c. Both a and b
d. None of the above
ANSWER: H tree
26) Increase in the physical distance of H-tree _________the skew rate.
a. Increases
b. Stabilizes
c. Decreases
d. All of the above
ANSWER: Increases
27) Which type of MOSFET exhibits no current at zero gate voltage?
a. Depletion MOSFET
b. Enhancement MOSFET
c. Both a and b
d. None of the above
ANSWER: Enhancement MOSFET
28) In enhancement MOSFET, the magnitude of output current __________ due to an increase
in the magnitude of gate potentials.
a. Increases
b. Remains constant
c. Decreases
d. None of the above
ANSWER: Increases
29) In DIBL, which among the following is/are regarded as the source/s of leakage?
a. Subthreshold conduction
b. Gate leakage
c. Junction leakage
d. All of the above
ANSWER: All of the above
30) Which among the following can be regarded as an/the application/s of MOS switch in
an IC design?
a. Multiplexing & Modulation
b. Transmission gate in digital circuits
c. Simulation of a resistor
d. All of the above
ANSWER: All of the above
31) In MOS switch, clock feedthrough effect is also known as __________.
A. charge injection
B. charge feedthrough
C. charge carrier
D. charge ejaculation
a. A & B
b. B & C
c. C & D
d. B & D
ANSWER: A & B
32) Which among the following is/are regarded as an/the active resistor/s?
a. MOS diode
b. MOS transistor
c. MOS switch
d. All of the above
ANSWER: MOS diode
33) In testability, which terminology is used to represent or indicate the formal evidences
of correctness?
a. Validation
b. Verification
c. Simulation
d. Integration
ANSWER: Verification
34) Which among the following is regarded as an electrical fault?
a. Excessive steady-state currents
b. Delay faults
c. Bridging faults
d. Logical stuck-at-0 or stuck-at-1
ANSWER: Excessive steady-state currents
35) Which among the following faults occur/s due to physical defects?
a. Process variations & abnormalities
b. Defects in silicon substrate
c. Photolithographic defects
d. All of the above
ANSWER: All of the above
36) In logic synthesis, ________ is an EDIF that gives the description of logic cells & their
interconnections.
a. Netlist
b. Checklist
c. Shitlist
d. Dualist
ANSWER: Netlist
37) Which level of system implementation includes the specific function oriented
registers, counters & multiplexers?
a. Module level
b. Logical level
c. Physical level
d. All of the above
ANSWER: Module level
38) Which among the following is/are taken into account for post-layout simulation?
a. Interconnect delays
b. Propagation delays
c. Logic cells
d. All of the above
ANSWER: All of the above
39) Which among the following operation/s is/are executed in physical design or layout
synthesis stage?
a. Placement of logic functions in optimized circuit in target chip
b. Interconnection of components in the chip
c. Both a and b
d. None of the above
ANSWER: Both a and b
40) In VHDL, which class of scalar data type represents the values necessary for a specific
operation?
a. Integer types
b. Real types
c. Physical types
d. Enumerated types
ANSWER: Enumerated types
41) Which among the following is pre-defined in the standard package as one-dimensional
array type comprising each element of BIT type?
a. Bit type
b. Bit_vector type
c. Boolean type
d. All of the above
ANSWER: Bit_vector type
42) In composite data type of VHDL, the record type comprises the elements of _______data
types.
a. Same
b. Different
c. Both a and b
d. None of the above
ANSWER: Different
43) Which among the following wait statement execution causes the enclosing process to
suspend and then wait for an event to occur on the signals?
a. Compilation
b. Elaboration
c. Execution
d. None of the above
ANSWER: Execution
ANSWER: Change on
48) Which among the following is/are regarded as the function/s of translation step in
synthesis process?
49) In synthesis flow, which stage/s is/are responsible for converting an unoptimized
boolean description to PLA format?
a. Translation
b. Optimization
c. Flattening
d. All of the above
ANSWER: Flattening
50) In synthesis flow, the flattening process generates a flat signal representation of
_____levels.
A. AND
B. OR
C. NOT
D. EX-OR
a. A & B
b. C & D
c. A & C
d. B & D
ANSWER: A & B
51) If the level of fan-out is beyond a limit in synthesis, it results in an insertion of buffer
by ultimate effect of _____ the speed.
a. Enhancing
b. Reducing
c. Stabilizing
d. None of the above
ANSWER: Reducing
55) In SM chart for UART transmitter, which state/s indicate/s the waiting of sequential
machine for the rising edge of bit clock and the consequent clearing of low order bit of TSR
in order to transmit logic 0 for one bit time?
a. IDLE State
b. Sync State
c. Transmit_Data_State
d. All of the above
ANSWER: Sync State
56) The devices which are based on fusible link or antifuse are _________time/s
programmable.
a. one
b. two
c. four
d. infinite
ANSWER: one
57) Which among the following is/are not suitable for in-system programming?
a. EPROM
b. EEPROM
c. Flash
d. All of the above
ANSWER: EPROM
58) Simple Programmable Logic Devices (SPLDs) are also regarded as _____________.
a. Programmable Array Logic (PAL)
b. Generic Array Logic (GAL)
c. Programmable Logic Array (PLA)
d. All of the above
ANSWER: All of the above
59) In signal integrity, which noise/s occur/s due to impedance mismatch, stubs, vias and
other interconnection discontinuities?
a. Power/Ground Noise
b. Crosstalk Noise
c. Reflection Noise
d. All of the above
62) In CMOS inverter, the propagation delay of a gate is the/an _________ transition delay
time for the signal during propagation from input to output especially when the signal
changes its value.
a. Highest
b. Average
c. Lowest
d. None of the above
ANSWER: Average
63) In pull-up network, PMOS transistors of CMOS are connected in parallel with the
provision of conducting path between output node & Vdd yielding _____ output.
a. 1
b. 0
c. Both a and b
d. None of the above
ANSWER: 1
64) For complex gate design in CMOS, OR function needs to be implemented by _______
connection/s of MOS.
a. Series
b. Parallel
c. Both series and parallel
d. None of the above
ANSWER: Parallel
65) In MOS devices, the current at any instant of time is ______of the voltage across their
terminals.
a. constant & dependent
b. constant & independent
c. variable & dependent
d. variable & independent
66) On the basis of an active load, which type of inverting CMOS amplifier represents low
gain with highly predictable small and large signal characteristics?
a. Active PMOS load inverter
b. Current source load inverter
c. Push-pull inverter
d. None of the above
69) Which type/s of stuck at fault model exhibit/s the reduced complexity level of test
generation?
a. Single
b. Multiple
c. Both a and b
d. None of the above
ANSWER: Multiple
a. Because single stuck-at fault model is independent of design style & technology
b. Because single stuck-at tests cover major % of multiple stuck-at faults & unmodeled
physical defects
c. Because complexity of test generation is reduced to greater extent in multiple stuck-at
fault models
d. All of the above
71) Which among the following EDA tool is available for design simulation?
a. OrCAD
b. ALDEC
c. Simucad
d. VIVElogic
ANSWER: VIVElogic
72) Which among the following functions are performed by MSI category of IC technology?
a. Gates, Op-amps
b. Microprocessor/A/D
c. Filters
d. Memory/DSP
ANSWER: Filters
73) The next statements skip the remaining statement in the ________ iteration of loop and
execution starts from first statement of next iteration of loop.
a. Previous
b. Next
c. Current (present)
d. None of the above
a. Sequential
b. Concurrent
c. Both a and b
d. None of the above
ANSWER: Both a and b
75) Timing analysis is more efficient with synchronous systems whose maximum
operating frequency is evaluated by the _________path delay between consecutive flip-flops.
a. shortest
b. average
c. longest
d. unpredictable
ANSWER: longest
77) Why is the use of mode buffer prohibited in the design process of synthesizer?
80) In Gray coding, when the state machine changes state, ______ bit/s in the state vector
changes the value.
a. one
b. two
c. four
d. eight
ANSWER: one
81) Which type of CPLD packaging comprises pins on all four sides that wrap around the
edges of chip?
82) An antifuse element initial provides ______ between two conductors in absence of the
application of sufficient programming voltage.
a. Conduction
b. Insulation
c. Both a and b
d. None of the above
ANSWER: Insulation
83) In spartan-3 family architecture, which programmable functional element accepts two
18 bit binary numbers as inputs and computes the product?
84) Which level of routing resources are supposed to be the dedicated lines allowing
output of each tile to connect directly to every input of eight surrounding tiles?
a. Viterbis algorithm
b. Lee/Moore algorithm
c. Prims algorithm
d. Quine-McCluskey algorithm
86) Maze routing is used to determine the _______path for a single wire between a set of
points, if any path exists.
a. Shortest
b. Average
c. Longest
d. None of the above
ANSWER: Shortest
87) In a chip, which type/s of pad design/s is/are adopted to solve the problem of pin
count?
88) The power consumption of static CMOS gates varies with the _____ of power supply
voltage.
a. square
b. cube
c. fourth power
d. 1/8 th power
ANSWER: square
89) Which factor/s play/s a crucial role in determining the speed of CMOS logic gate?
a. Load capacitance
b. Supply voltage
c. Gain factor of MOS
d. All of the above
90) In high noise margin (NMH), the difference in magnitude between the maximum HIGH
output voltage of driving gate and the maximum HIGH voltage is recognized by the
_________gate.
a. Driven
b. Receiving
c. Both a and b
d. None of the above
ANSWER: Receiving
91) In CMOS circuits, which type of power dissipation occurs due to switching of transient
current and charging & discharging of load capacitance?
a. Static dissipation
b. Dynamic dissipation
c. Both a and b
d. None of the above
ANSWER: Dynamic dissipation
92) In accordance to the scaling technology, the total delay of the logic circuit depends on
______
a. The capacitor to be charged
b. The voltage through which capacitance must be charged
c. Available current
d. All of the above
ANSWER: All of the above
93) In two-stage op-amp, what is the purpose of compensation circuitry?
a. To provide high gain
b. To lower output resistance & maintain large signal swing
c. To establish proper operating point for each transistor in its quiescent state
d. To achieve stable closed-loop performance
94) According to the principle of current mirror, if gate-source potentials of two identical
MOS transistors are equal, then the channel currents should be _______
a. Equal
b. Different
c. Both a and b
d. None of the above
ANSWER: Equal
95) PSSR can be defined as the product of the ratio of change in supply voltage to change
in output voltage of op-amp caused by the change in power supply & _______ of op-amp.
a. Open-loop gain
b. Closed-loop gain
c. Both a and b
d. None of the above
96) Which among the following serves as an input stage to most of the op-amps due to its
compatibility with IC technology?
a. Differential amplifier
b. Cascode amplifier
c. Operational transconductance amplifiers (OTAs)
d. Voltage operational amplifier
97) Which among the following is/are responsible for the occurrence of Delay Faults?
a. Lower than
b. Equal to
c. Greater than
d. None of the above
99) High observability indicates that ________number of cycles are required to measure the
output node value.
a. More
b. Equal
c. Less
d. None of the above
ANSWER: Less
100) Basically, an observability of an internal circuit node is a degree to which one can
observe that node at the _______ of an integrated circuit.
a. Inputs
b. Outputs
c. Both a and b
d. None of the above
ANSWER: Outputs
1 In accordance to the scaling technology, the total delay of the logic circuit depends on
______
A.The capacitor to be charged
b. The voltage through which capacitance must be charged
c. Available current
d. All of the above
a. Load capacitance
b. Supply voltage
c. Gain factor of MOS
d. All of the above
For complex gate design in CMOS, OR function needs to be
implemented by _______ connection/s of MOS.
a. Series
b. Parallel
c. Both series and parallel
d. None of the above
In pull-up network, PMOS transistors of CMOS are connected in parallel
with the provision of conducting path between output node &
Vddyielding _____ output.
a. 1
b. 0
c. Both a and b
d. None of the above
In CMOS inverter, the propagation delay of a gate is the/an _________
transition delay time for the signal during propagation from input to
output especially when the signal changes its value.
a. Highest
b. Average
c. Lowest
d. None of the above
In DIBL, which among the following is/are regarded as the source/s of
leakage?
a. Subthreshold conduction
b. Gate leakage
c. Junction leakage
d. All of the above
In enhancement MOSFET, the magnitude of output current __________
due to an increase in the magnitude of gate potentials.
a. Increases
b. Remains constant
c. Decreases
d. None of the above
Which type of MOSFET exhibits no current at zero gate voltage?
a. Depletion MOSFET
b. Enhancement MOSFET
c. Both a and b
d. None of the above