Intel White Paper on FPGA Power Management and Modeling Techniques

FPGA Power Management and Modeling

Techniques

WP-01044-2.0 White Paper

This white paper discusses the major challenges associated with accurately predicting power consumption in FPGAs, namely, obtaining accurate signal activities, static power modeling, and dynamic power modeling, as well as how Altera addresses these challenges through the Power Play early power estimator and the Quartus® II Power Play power analyzer. This paper also presents the accuracy of the model by comparing predicted power consumption with actual silicon measurements using an extensive suite of real-world customer designs. Using these best-in-class power analysis tools, a designer can model the power consumption of their design to within, on average, ±10% accuracy when used with accurate design information.

Introduction

As designs get larger and add more system functions implemented on FPGAs, and as the advanced silicon process technology moves into smaller geometries, power consumption is increasingly a concern for today’s FPGAs. When designing a printed circuit board (PCB), the power consumed by a device determines not only the power supply, but also the cooling system required for the device. Therefore, obtaining an accurate estimate of power consumption is essential to design a system’s power supplies, voltage regulators, heat sink, and cooling system, and is crucial in developing an appropriate power budget for the entire system.

Factors Contributing to Accurate Power Estimates

Obtaining an accurate power estimate relies on two important factors: accurate signal activities and accurate power models. Power models define the power characteristics of the device, and the signal activities define the behavioral characteristics of each signal in the design. While the power models are provided by FPGA vendors, the designer must provide accurate signal activities to obtain the best possible estimate of overall power consumption.

Signal Activities

A good power analysis tool should provide a flexible framework for specifying signal activities. Using representative signal activity data during power analysis is important, as inaccurate signal activity data is the largest source of power estimation error.

Altera’s Power Play power analysis tools use the following sources to provide information on signal activity:

Simulation results

User-entered node, entity, and clock assignments

© 2010 Altera Corporation. Al l rights reserved. ALTERA, ARRIA, CYCLONE, HARDCOPY, MAX, MEGACORE, NIOS, QUARTUS and STRATIX are Reg. U.S. Pat. & Tm. Off. and/or trademarks of Altera Corporation in the U.S. and other countries. All other trademarks and serv ice marks are the property of their respective holders as described at www.altera.com/common/le gal.html. Altera warrants performance of its semiconductor products to current specifications in 101 Innovation Drive accordance with Altera’s stand ard warranty, but reserves the right to make changes to any products and services at any time without notice. Altera assume s no responsibility or liability arising out of the application or use of any information, product, or

San Jose, CA 95134 service described herein excep t as expressly agreed to in writing by Altera. Altera customers are advised to obtain the latest

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www.altera.com

December 2010 Altera Corporation

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