Đề thi môn: ASSIGNMENT - 5 doc

Design a fast 6-input OR gate in each of the following circuit families.. Sketch an implementation using two stages of logic e.g., NOR6 + INV, NOR3 + NAND2, etc... Label each gate with t

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Thuan Xuan Nguyen

Department of Electronics and Telecommunications

University of Science, Ho Chi Minh City

Vietnam National University, Ho Chi Minh City

Tel: (+84) 906 834 817

Email: thuannguyen.teaching@gmail.com

Site: http://www.thuanxuannguyen.tk/

ASSIGNMENT #5

Edited: Monday, April 25 2011 Exercise 1, 7: Use Vietnamese only

1 Based on Section 6.3 – Circuit Pitfalls (page 379/1003), explain those concepts by using images and examples

a Threshold Drops

b Ratio Failures

c Leakage

d Charge Sharing

e Power Supply Noise

f Hot spots

g Minority Carrier Injection

h Back-gate Coupling

i Diffusion Input Noise Sensitivity

j Process sensitivity

2 Design a fast 6-input OR gate in each of the following circuit families Sketch an implementation using two stages of logic (e.g., NOR6 + INV, NOR3 + NAND2, etc.) Label each gate with the width of the pMOS and nMOS transistors Each input can drive no more than 30 lamda of transistor width The output must drive a 60/30 inverter (i.e., an inverter with

a 60 lamda-wide pMOS and 30 lamda-width nMOS transistor) Use logical effort to choose the topology and size for least average delay Estimate this delay using logical effort When estimating parasitic delays, count only the diffusion capacitance on the output node

a Static CMOS

b Pseudo-nMOS with pMOS transistors ¼ the strength of the pull-down stack

c Domino (a footed dynamic gate followed by a HI-skewed inverter); only optimize the delay from rising input to rising output

3 Prove that the P/N ratio that gives lowest average delay in a logic gate is a square root of the ratio that gives equal rise and fall delays

4 Sketch a pseudo-nMOS gate that implements the function

( ) ̅̅̅̅̅̅̅̅̅̅̅̅̅̅̅̅̅̅̅̅̅̅̅̅̅̅̅̅̅̅

Calculate the gu, gd, gavg, pu, pd, pavg of this circuit

5 Sketch a 3-input dual-rail domino majority/minority gate This is often used in domino full adder cells Recall that the majority function is true if more that half of the inputs are true

6 Sketch 3-input XOR functions using each of the following circuit techniques and give the comparison of them (ref 6.6 Comparison of Circuit Families):

a Static CMOS

b Pseudo-nMOS

c Dual-rail domino

d CPL

e EEPL

f DCVSPG

g SRPL

h PPL

i DPL

j LEAP

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7 In May, 2011, Intel made one its most significant technology announcements ever today by stating it will base upcoming processors on 3D transistors So, what is a 3D transistor exactly and why is it important? Represent your answer in about 500 words (use images to illustrate your answer)