VLSI QUESTION PAPER

1. Course Outcomes – EC8095-VLSI DESIGN
After successful Completion of the Course, the Students should be able to
CO1 Realize the concepts of digital building blocks using CMOS Transistors
CO2 Design Combinational MOS CIRCUITS and Power Stratergies
CO3 Design and construct Sequential circuits and Timing Systems
CO4 Design Arithmatic Building Blocks and Memory systems
CO5 Apply and Implement FPGA design flow and Testing
Knowledge Level (Blooms Taxonomy)
K1 Remembering (Knowledge) K2 Understanding (Comprehension) K3
Applying
(Application
of
Knowledge)
K4 Analysing (Analysis) K5 Evaluating (Evaluation) K6
Creating
(Synthesis)
Part Question Mapping with Course Outcomes and Knowledge Level
Part -A
Question No. 1 2 3 4 5 6 7 8 9 10
Course Outcome CO1 CO1 CO2 CO2 CO3 CO3 CO4 CO4 CO5 CO5
Knowledge Level K2 K3 K4 K3 K3 K3 K2 K3 K3 K3
Part Part –B Part - C
Question No. 11 (a) 11(b) 12(a) 12(b) 13(a) 13(b) 14(a) 14(b) 15(a) 15(b) 16 (a) 16(b)
Course Outcome CO1 CO1 CO2 CO2 CO3 CO3 CO4 CO4 CO5 CO5 CO1 CO5
Knowledge Level K3 K4 K4 K4 K3 K4 K4 K4 K3 K3 K4 K4

2. Saveetha Nagar, Thandalam, Chennai – 602105
MODEL EXAM #3 – June 2021
Degree : B.E / Branch : ECE / Semester :VI Sem Date : 10.06.2021/Session :AN/ Duration : 3 hours
EC8095/ VLSI DESIGN Time : 4.PM to 7PM
Total Marks: 100
PART – A 10X2 = 20 marks
1. Define Logical effort and Electrical effort.
2. A 90 nm long transistor has a gate oxide thickness of 16 𝐴̇. Estimate its gate capacitance
per micron of width?(Assume 𝜀𝑟=3.9).
3. Implement a 2 input AND gate using Pass transistor logic.
4. Compare noise margins between Static CMOS and Pseudo NMOS circuits.
5. Define set-up time and hold time of flip flop.
6. Differentiate Latch and Flipflops.
7. What is datapath of the processor? State its functions.
8. What is propagation delay of n-bit ripple carry adder?
9. Define controllability and observability of circuit.
10. Analyze Stuck-at-1 and Stuck-at-0 faults.
PART – B 13X5 = 65 marks
11(a) Discuss in detail different types of scaling and their impact on device performance.
(or)
11(b) Explain the operation of n-MOS transistor and hence obtain its I-V characteristics.
12(a) (i) Sketch the schematic of Pseudo NMOS gate that implements the function
Analyze the advantages and disadvantages of Pseudo –NMOS circuits ( 6 Marks)
Implement the function F in (i) using Static CMOS circuit and analyse its advantages over Pseudo NMOS (7 Marks).
(or)

3. 12(b) Explain in detail implementation of combinational circuits using Pass transistor, Transmission gate and CPL logic families with suitable
examples and analyze their performances in terms of power, speed and area
13(a) Write short notes on: (i) Multiplexer-Based Latches (7 Marks)
(ii) Low-Voltage Static Latches.(6 Marks)
(or)
13(b) Explain in detail the construction and working of Sense amplifier based registers in detail.
14(a) Explain in detail the operation of 16 bit Kogge stone Lookahead Logarithimic adder
(or)
14(b) Explain the principle and working of 6T CMOS SRAM cell Read and Write operations.
15 (a) (i) Explain the general architecture of Xilinx FPGA ( 4 Marks)
(ii)Explain in detail the architecture of Xilinx XC2000 and Xilinx XC3000 FPGA.s (9 Marks)
(or)
15 (b) (i)Explain in detail the routing procedure in Actel ACT1 FPGA ( 6 Marks )
(ii) Explain in detail the routing procedure in Xilinx XC4000 FPGA ( 7 Marks )
PART – C 15X1 = 15 marks
16 (a) (i) Realize a 4 bit Array multiplier and hence analyse its operation.(7)
(ii) Construct analyze and obtain propagation delay of a 4 bit Carry Save multiplier.(8)
(or)
16 (b) (i)Realize the schematic and working of a master slave negative edge triggered register that is insensitive to Clock skew.(5Marks)
(ii)Discuss how the negative edge triggered register is skew insensitive during 0-0 overlap and 1-1 overlap with neat diagrams(6 Marks)
(iii) Explain the operation of True Single-Phase Clocked Register (TSPCR) ( 4)