LFEC10E-3F256C Lattice Semiconductor Corp., LFEC10E-3F256C Datasheet - Page 197

• Manufacturer Part Number: LFEC10E-3F256C
• Description: Latticeecp/ec Family of Fpga Devices Has Been Optimized to Deliver Mainstream Fpga Features at Low Cost.for Maximum Performance And Value, The Latticeecp (EConomy Plus) Fpga Concept Combines an Efficient Fpgafabric With High-speed Dedicated Functions
• Manufacturer: Lattice Semiconductor Corp.

© 2004 Lattice Semiconductor Corp. All Lattice trademarks, registered trademarks, patents, and disclaimers are as listed at www.latticesemi.com/legal. All other
brand or product names are trademarks or registered trademarks of their respective holders. The specifications and information herein are subject to change without
notice.
June 2004
Introduction
One of the requirements when using FPGA devices is the ability to calculate power dissipation for a particular
device used on a board. Lattice’s ispLEVER
to calculate the power dissipation for a given device. This technical note explains how to use Power Calculator to
calculate the power consumption of Lattice devices. General guidelines to reduce power consumption are also
included.
Power Calculator Hardware Assumptions
The power consumption for a device can be coarsely broken down into the DC portion and the AC portion.
The power calculator reports the power dissipation in terms of:
The DC power (or the static power consumption) is the total power consumption of the used and unused resources.
These components are fixed for each resource used and depend upon the number of resource units utilized. The
DC component also includes the static power dissipation for the unused resources of the device.
The AC portion of power consumption is associated with the used resources and it is the dynamic part of the power
consumption. Its power dissipation is directly proportional to the frequency at which the resource is running and the
number of resource units used.
Power Calculator
Power Calculator is a powerful tool which allows users to make an estimate of the power consumption at two differ-
ent levels:
For first level estimation, the user provides estimates of device usage in the Power Calculator Wizard and the tool
provides a rough estimate of the power consumption.
The second level is a more accurate approach where the user imports the actual device utilization by importing the
post Place and Route netlist (NCD) file.
Power Calculator Equations
The power equations used in the Power Calculator are listed below.
Total DC Power (Resource)
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1. DC portion of the power consumption.
2. AC portion of the power consumption.
1. Estimate of the utilized resources before completing place and route
2. Post place and route design
= Total DC Power of Used Portion + Total DC Power of Unused Portion
= [DC Leakage per resource when Used * N
+ [DC Leakage per resource when Unused * (N
Calculator for LatticeECP/EC Devices
®
design tools include a Power Calculator tool which allows designers
Estimating Power Using the Power
RESOURCE
12-1
TOTAL RESOURCE
]
- N
RESOURCE
)]
Technical Note TN1052
tn1052_01