ELEC5970-003/6970-003/Fall 2004
Advanced Topics in Electrical Engineering
Designing VLSI for Low-Power and Self-Test
Class Projects and Presentations
Vishwani D. Agrawal
James J. Danaher Professor
Department of Electrical and Computer Engineering
Auburn University
http://www.eng.auburn.edu/~vagrawal
vagrawal@eng.auburn.edu
9/21/04
ELEC 5970-003/6970-003 Class
Projects
1
Student Evalulation
• Homework (30%) – three
• Student presentation (10%)
• Research paper (30-60%) – a publishable
paper will exempt the student from the
final exam
• Final Exam (0-30%)
9/21/04
ELEC 5970-003/6970-003 Class
Projects
2
Project 1: Mixed-Signal BIST
• Select an analog function in a mixedsignal environment.
• Develop a specification-based test
procedure.
• Design a digital TPG and an ORA with
measurable output.
• Analyze ORA for tolerance characteristic
and aliasing.
9/21/04
ELEC 5970-003/6970-003 Class
Projects
3
Mixed-Signal BIST – Stroud, Dai
• Digital circuitry tests analog circuitry
– Minimum overhead & impact to analog circuitry
Capable of automatic measurement: gain, linearity
• Developed parameterized HDL models
– Automatic synthesis in any mixed-signal system
Digital Circuitry
Analog Circuitry
Digital
System
Inputs
System
Function
Mux
DAC
101011000111011010
BIST Start
TP
G
BIST Done
Pass/Fail
Digital
System
Outputs
9/21/04
Analog
System
Outputs
Analog
Circuit
Test
Control
Analog
MUX
Analog
System
Inputs
ORA
101011000111011010
System
ADC
Function
ELEC 5970-003/6970-003 Class
Projects
Analog
Circuit
4
Reference
• F. Dai, C. Stroud, D. Yang and S. Qi,
“Automatic Linearity (IP3) Test with Built-In
Pattern Generator and Analyzer,” Proc.
International Test Conference, October
2004.
• M. Burns and G. W. Roberts, An
Introduction to Mixed-Signal IC Test and
Measurement, New York: Oxford
University Press, 2001.
9/21/04
ELEC 5970-003/6970-003 Class
Projects
5
Project 2: Spectral BIST
• Develop TPG and ORA circuits for testing
of digital circuits.
• Analyze overhead, coverage and aliasing.
9/21/04
ELEC 5970-003/6970-003 Class
Projects
6
Spectral Testing
Main ideas:
– Meaningful inputs (e.g., test vectors) of
a circuit are not random.
– Input signals have spectral
characteristics that are different from
white noise (random vectors).
9/21/04
ELEC 5970-003/6970-003 Class
Projects
7
Statistics of Test Vectors
100% coverage
Tests:
a 00011
b 01100
c 10101
a
b
c
Test vectors are not random:
1. Correlation: a = b frequently used.
2. Weighting: c has more 1s than a or b.
9/21/04
ELEC 5970-003/6970-003 Class
Projects
8
Spectral Test Generation
Initial vectors
(random)
Fault simulation
and vectorcompaction
Add filtered
vectors to
test set
9/21/04
Fault
coverage
?
ok
Stop
low
Compute
(Hadamard
spectral
Functions)
coefficients
ELEC 5970-003/6970-003 Class
Projects
9
Spectral Test Results
Circuit
name
HITEC
Det vec CPU s
Strategate
Det vec CPU s
s5378
3231 912 1104
3639 11571 2268
3643
1488 33113 9659
1645 4464
b12
-
-
-
Spectral ATPG
Det vec CPU s
734 44
24
CPU: Ultra Sparc 10
HITEC: Nierman and Patel, EDAC’91
Strategate: Hsiao et al., ACMTDAES’00
9/21/04
ELEC 5970-003/6970-003 Class
Projects
10
Reference
• A. Giani, S. Sheng, M. S. Hsiao, and V. D.
Agrawal, “Novel Spectral Methods for
Built-In Self-Test in a System-on-a-Chip
Environment,” Proc. 19th IEEE VLSI Test
Symp., 2001, pp. 163-168.
9/21/04
ELEC 5970-003/6970-003 Class
Projects
11
Project 3: Low-Power Adiabatic
Logic
• Basic Idea – If we charge a capacitor C to
voltage V in n equal increments, then the
energy required by each increment is
C(V/n)2 = (1/n2) CV2
• The total energy of n-step charging is 1/n
of that required to charge the capacitor to
the full voltage V in one step.
9/21/04
ELEC 5970-003/6970-003 Class
Projects
12
Adiabatic CMOS Circuits
• Low-Power circuits have been designed
with time-varying (periodic) power supply.
• The objective is to analyze:
– Effect of the shape (sinusoidal, triangular,
etc.) of the power supply waveform on power
dissipation.
– Effect of the supply frequency on delay and
power of the circuit.
– Possibly treat supply as AC instead of DC.
9/21/04
ELEC 5970-003/6970-003 Class
Projects
13
Related Ideas for Investigation
• Energy recovery
VDD
• Reversible Logic
9/21/04
ELEC 5970-003/6970-003 Class
Projects
14
Reference
• Y. Ye and K. Roy, “QSERL: Quasi-Static
Energy Recovery Logic,” IEEE J. Solid
State Circuits, vol. 36, no. 2, pp. 239-248,
Feb. 2001.
9/21/04
ELEC 5970-003/6970-003 Class
Projects
15
Project 4: Submicron Leakage
Power Reduction
• Recent references.
9/21/04
ELEC 5970-003/6970-003 Class
Projects
16
Project 5: ISA for Low Power
• Recent references.
9/21/04
ELEC 5970-003/6970-003 Class
Projects
17
Project 6: Power Estimation
Algorithms
• Mixed-levels of hierarchy
• Glitch, leakage and short-circuit power
• Recent references
9/21/04
ELEC 5970-003/6970-003 Class
Projects
18