CSE591 Low Power Architecture

29 Jan 07 Presentation I

Instruction Level Power Dissipation in the Intel XScale Embedded Microprocessor

Tools for power analysis of microprocessors at the microarchitectural level:

• SimpleScalar computer architecture simulator

• Wattch: a framework for architectural-level power analysis and optimizations

This software is based on the SimpleScalar software

Download Wattch

• SimplePower "A cycle accurate energy simulator"

12 Feb 07 Project I due

• Pentium D specifications (65nm, up to 5GHz)

-Thermal/Failure Rate relationships, Fig. 4-27

Project II

• XScale project using PXA250 80200 already in Dr. Shrivastava's possession.

19 Feb 07 Presentation II

• Mitigating Amdahl’s Law Through EPI Throttling

-Energy Efficient Co-Adaptive Instruction Fetch and Issue (Throttling paper)

-Instruction Flow-Based Front-end Throttling for Power-Aware High-Performance Processors (Throttling paper)

• Amdahl's Law (Wikipedia)
• Intel article on EPI throttling
• Best of Both Latency and Throughput (introduces EPI Throttling)

Vocabulary

Wall clock time

5 March 07 Project I.2

Considerations:

• Existing power reduction schemes for LCDs and their applicability to Electrophoretic Displays (EPDs)

-Dynamic Backlight and Contrast Scaling

• The advantages of bi-stability of EPD over constant refresh of LCD

-Possibility of redraw circuitry for bi-stable display which only addressed pixels which need to be updated

• Relevance of the backlight in LCD in comparison with "front-light" in EPD

-Best-case/Worst-case for each display and in what circumstances are they opposed, in what circumstances are they matched

• Power characterization of power consumption of the LCD vs. the EPD
• Power Modeling for LCD and EPD

-Traditionally pixel switching has been ignored because it is insignificant compared to backlight and control circuitry, is the EPD a different case

-LCD switching power modeled as capacitors (1.16, 1.5, 1.10)

-EPD switching power modeled as resistor (1.12)