ECE
558 Introduction to VLSI Design
ECE
658 (NTU
IC760-A) VLSI Design Principles
Homework 1
Assigned in Lecture 3, Due in
Lecture 5
This homework Covers Lectures 1,2,3 and RCN Chapter
1. For each problem I suggest how long I expect you to spend, assuming you
have done the reading already. Sections that are marked GRAD ONLY are
additional problems just for ECE 658 and Off-campus students and are more
challenging, open-ended and not included in the time estimate :). 558
students can try them for extra credit. After the due date, a pair of
Grad students will be assigned to develop solutions for each homework to be
distributed to the entire class. We will all rate these solutions and a
grade will be given that will contribute to the overall hw
grade of each grad student.
Undergrads, Grads and Off-campus: (Total time: 145 minutes = 2.5 hours
approx)
- (30 Minutes) Extrapolate the curves shown in the
book and slides to indicate various CMOS technology characteristics for
the year 2015? Specifically indicate feature size, clock rate,
power, and number of transistors? GRAD ONLY: Give equations
for each of these (i.e. curve-fit) to compute these numbers for an
arbitrary year in the future?
- (30 Minutes)
Yield. Modify Example 1.3 to assume a defect density of 2/cm2 . GRAD ONLY: If an IC fab invests 10 million dollars in their clean-room
facilities to reduce defect density by 50%, how many wafers are needed to
recover these costs? Make appropriate assumptions of die size,
initial defect density, etc.
- (20 minutes)
Briefly explain the significance of the global nature of clock and power
signals. The text emphasizes how these particular signals defy (or
transcend) hierarchy. What does this mean?
- (15 minutes)
What is meant by a voltage transfer characteristic? Why might a
voltage transfer characteristic be assymetric?
Does the VTC tell you anything about the timing of the circuit?
- (30 minutes)
Briefly explain how noise margins are calculated and why. GRAD
ONLY: Both on-chip noise and manufacturing defects can be
described as random processes. Explain the differences in the
statistical models and their determinism.
- (20 minutes) Explain
why ring oscillators are used to characterize the performance of a process
and the limitations of this technique. Explain the terms in the
equation used to calculate the ring oscillator frequency. GRAD
ONLY: Compute the power of a ring oscillator as a function of
the number of inverter stages.
- (30 minutes)
Explain the difference between power and energy. How many joules are
stored in a laptop battery if the system consumes about 30W and the
battery life is about 2hours? How many watts are needed to charge
and discharge a 1pF capacitor with VDD= 1V and frequency of 1 Ghz? GRAD ONLY:
Show how peak power can far exceed average power in certain power-up
situations.
HAVE FUN!
--
Wayne Burleson, Professor,
Electrical and Computer Engineering
Knowles Eng. Building 309C,
University of Massachusetts, Amherst, MA 01003
voice: 413-545-2382, fax: 413-545-1993
email: burleson@ecs.umass.edu
web: http://www.ecs.umass.edu/ece/vspgroup/burleson.html
office manager: (Christine Langlois) langlois@ecs.umass.edu 413-545-3621