B.E (E&TC)

VLSI QUESTIONS

UNIT-1

1. Draw the VLSI design flow?
2. What is meant by simulation?
3. What is meant by synthesis?
4. What is meant by net list?
5. Explain the term UCF?
6. How many methods are used to enter the design of your circuit?
7. What is meant by floor planning?
8. What is meant by mapping?
9. What is the difference between CPLD and FPGA?
10. Define the term 'TECHNOLOGY LIBRARY'?
11. What are the features of VHDL language?
12. Explain the VHDL program format?
13. Explain the difference between signal and variables?
14. Is it possible to change the floorplan of your design?
15. How many types of VHDL modeling are there?
16. Explain the data flow modeling in short?
17. Explain the term ‘process’?
18. Explain the structural modeling in short?
19. Write down the syntax of case statement in short?
20. Write down the VHDL program of 4:1 mux using with-select statement?
21. Explain the difference between function and procedure?
22. Explain the term configuration?
23. Explain the test benches in short?
24. Explain the difference between the data flow modeling and sequential modeling?
25. Define the term ‘Entity’?
26. Define the term ‘Architecture’?

UNIT-2

27. Explain the difference between sequential and combinational circuit?
28. Explain the difference between mealy and moore machine?
29. Explain the necessity of state machines?
30. Explain the difference between asynchronous and synchronous sequential circuits?
31. Define FSM?
32. What are the merits and demerits of synchronous system design?
33. What are the advantages and demerits of describing state machines with the state diagram compared to truth table and K-map?
34. Explain the timing considerations in sequential circuits?
35. Design lift controller system using VHDL?

UNIT-3

36. Which type of technology is used in CPLD?
37. Define macrocell?
38. Explain the CPLD programming?
39. What are the features of in-system programming?
40. Define the JTAG?
41. What are the features of Xilinx XC9500XV CPLD?
42. What is the function of product term allocator?
43. Explain the function of fast connect II Switch matrix in CPLD?
44. What are the programmable elements for FPGA?
45. Explain the configurable logic blocks of FPGA?
46. What are the features of Spartan-3 FPGA family?
47. What are the series of CPLD?
48. What are the series of FPGA?
49. What are the functions of FPGA’s today?
50. Explain the comparison of PLD’s, ASIC’s and FPGA’s?
51. What is the difference between logic implemented in CPLD and in that of FPGA?
52. What is the role of CPLD and FPGA in embedded system development?
53. What are the advantages of CPLD?
54. What are the advantages of FPGA?
55. What is VLSI?
56. What are the advantages of VHDL?
57. What are the elements of VHDL?
58. What are the levels of abstraction of VHDL?
59. What are the data types of VHDL?
60. What are the operators of VHDL?
61. Define attributes?
62. What are the types of simulation?
63. Explain the simulation process in short?
64. Explain the register transfer level in short?
65. Explain the synthesis process in short?
66. Explain the term constraints?
67. What are the steps in synthesis?
68. What are the advantages of synthesis?

UNIT-4

69. What is system on chip?
70. What are the important issues in SOC design?
71. Explain the single phase clock in short?
72. What is power distribution?
73. What is clock distribution?
74. Explain the global routing in short?
75. What is the goal of floorplanning?
76. What is switch box routing?
77. What is the main function of package?
78. Explain the DRC in short?
79. What is RAM?
80. Explain the wire parasitics in short?
81. Compare placement and routing?
82. What is Via in CMOS fabrication?
83. Explain I/O architecture?

UNIT-5

84. Explain the MOS structure?
85. Explain the difference between PMOS and NMOS?
86. What are the types of MOS?
87. Define the term threshold voltage?
88. What is body effect?
89. Why is it necessary to give floating VDD to PMOS?
90. Why floating VDD is absent in NMOS?
91. Compare CMOS technology with bipolar technology in short?
92. Explain the working of CMOS inverter in short?
93. What is technology scaling?
94. Implement the following equation using CMOS?

                   Y=A+B+C

95. Explain transmission gates in short?
96. Explain static and dynamic power dissipation?
97. Explain the parasitic capacitances in CMOS?
98. How many fabrication process of CMOS?

UNIT-6

99.            Explain the need of design for testability?
100. Compare testability and verification?
101. What are the fault models?
102. What is meant by boundary scan?
103. Explain the controllability in short?