VLSI Interview Questions-1

1.What is the difference between mealy and moore state-machines.
2.How to solve setup and hold violations in the design.
3.What is antenna violation & ways to prevent it.
4.We have multiple instances in RTL(Register Transfer Language), do you do anything special during synthesis stage.
5.What is tie-high and tie-low cells and where it is used.
6.What is the difference between latches and flip-flops based designs.
7.What is High-Vt and Low Vt cells.
8.What is LEF mean?
9.What is DEF mean?
10.Steps involved in designing an optimal padring.
11.What is metastability and steps to prevent it.
12.What is local-skew, global skew and useful skew.
13.What are the various timing-paths which i should take care in my STA runs?
14.What are the various components of leakage-power.
15.What are the various yield losses in the design.
16.What is meant by virtual clock definition and why do i need it.
17.What are the various variations which impacts timing of the design.
18.What are the various Design constraints used, while performing synthesis for a design.
19.Specify few verilog constructs which are not supported by the synthesis tool.
20.What are the various capacitances with an MOSFET?
21.Vds-Ids curve for an MOSFET, with increasing Vgs.
22.Explain basic operation of an MOSFET.
23.what is channel length modulation.
24.what is body effect.
25.what is latchup in CMOS design and ways to prevent it?
26.what are the various design changes you do to meet design power targets.
27.what is meant by library characterization.
28.what is meant by wireload model.
29.what are the measures to be taken to design for optimized area.
30.what all will you be thinking while performing floorplan.
31.what are the measures in the design taken for meeting signal integrity targets.
32.what are the measures taken in the Design achieving better yield.
33.what are the measures or precautions to be taken in the design when the chip has both analog and digital portions..
34.what are the steps incorporated for Engineering Change order[ECO].
35.what are the steps performed to achieve Lithography friendly Design.
36.what does synthesis mean?
37.what are the pre-requistes to perform synthesis.
38.Can you explain the synthesis flow.
39.what are the various ways to reduce clock insertion delay in the design.
40.what are the various functional verification methodologies.
41.what does formal verification mean.
42.How will you time the output path in STA.
43.How will you time the input path in STA.
44.What is false path mean in STA and in what scenarios falsepath can come.
45.What does multicycle path mean in STA and in what scenarios MCP can come.
46.What are source synchronous paths in STA.
47.Assume there is a specific requirement to preserve the logic during synthesis , how will you achieve it..
48.we have multiple instances in RTL, do you do anything special during synthesis stage.
49.What do you call an event and when do you call an assertion.