Ahmed Eltawil, UC Irvine #mobilizeconf More at http://event.gigaom.com/mobilize/

1. COGNITIVE POWER MANAGEMENT
Ahmed Eltawil
Professor
UC Irvine
Wednesday, November 7, 12

2. Cognitive Power
Management
Ahmed Eltawil
Fadi Kurdahi
Muhammad S. Abdelghaffar
Amr M. Hussien
Wednesday, November 7, 12

3. The Power Challenge
3
Wednesday, November 7, 12

4. The Power Challenge
3
Wednesday, November 7, 12

5. The Power Challenge
Logic vs memory power
(ITRS)
3
Wednesday, November 7, 12

6. The Power Challenge
Power density limit of handheld
Logic vs memory power
(ITRS)
3
Wednesday, November 7, 12

7. The Power Challenge
Power density limit of handheld
Logic vs memory power
(ITRS)
3
Wednesday, November 7, 12

8. The Power Challenge
Power density limit of handheld
1. Power is the key Logic vs memory power
2. Embedded memories are
(ITRS)
dominant
3
Wednesday, November 7, 12

9. Concept System Model
Noisy
Noisy Wireless
Wireless Receiver
Channel
Noise is
uncontrollable and is
a function of the Errors are controllable!
environment. Errors and power
consumption are
inversely related.
Current Design Approach
Specs
Overdriven Vdd
Nominal Vdd
Low Vdd
Memory typically consumes
Aggressively approximately
Low Vdd Memory Array 50% of the chip area and/or power
x
Management Cycle
System Design: Circuit Design: Memory noise and power ü Observe the channel statistics and system state
Assume worst case
wireless conditions
Minimize noise at consumption can be directly üTake the action and modulate the supply voltage
expense of power
controlled by the supply voltage ü Monitor performance metrics such as BER, PSNR and
Wednesday, November 7, 12

10. CPM Approach
n Created a statistical model for both
Channel+HW noise
n Created a new class of FEC decoders for
combined Channel and hardware noise
q Viterbi, Turbo, LDPC
q Negligible hardware overhead 0.013%-0.65%
n Created a design exploration framework
for designers to easily experiment with
different power management schemes by
propagating error statistics through the
system.
n Approach is not limited to data path
memories but can be extended to control
memories and logic with some
modifications.
Wednesday, November 7, 12

11. CPM Approach
n Created a statistical model for both
Channel+HW noise
n Created a new class of FEC decoders for
combined Channel and hardware noise
q Viterbi, Turbo, LDPC
q Negligible hardware overhead 0.013%-0.65%
n Created a design exploration framework
for designers to easily experiment with
different power management schemes by
propagating error statistics through the
system.
n Approach is not limited to data path
memories but can be extended to control
memories and logic with some
modifications.
Wednesday, November 7, 12

12. Technology Demonstration
Matlab
Demonstration Experimental FEC
http://www.youtube.com/watch? Demonstration
v=XI9E7Fr5TNY. http://www.youtube.com/watch?v=h1yKDcGLLb0
Wednesday, November 7, 12

13. Wednesday, November 7, 12

14. Wednesday, November 7, 12