[TechView: Digital]
10 FPGA Tricks Provide Power-Saving Treats
Fares Mubarak
ED Online ID #18325
March 13, 2008
Copyright © 2006 Penton Media, Inc., All rights reserved. Printing of this document is for personal use only.
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1. Select an FPGA with an ASIC-like
power profile. That means no inrush
power, no boot-up configuration power,
ultra-low standby power (especially
over extended temperature ranges),
and low dynamic power. Low-power
and secure in-system programmability
allow secure design modifications and
field upgrades.
2. Look for single-chip, small-form-factor
(portable-friendly) FPGAs. The ASIC-like
form factor is the smallest footprint available
for an FPGA solution. No configuration
PROM, brownout detection, clock management,
or supply-sequencing chip is required,
minimizing system power consumption.
3. Look for low power even at million-gate
densities and at high temperature. SRAM
FPGAs are power-hungry in standby and
active modes and at high-temperature
operation. Use flash FPGAs, which offer orders-of-magnitude lower power in standby
and active modes, across temperatures.
4. Extend battery life with low-power modes.
The availability of low-power modes further
reduces total system power when the system
is idle. Easy-to-use modes in low-power flash
FPGAs can reduce current consumption to as
low as 5 µW in Flash*Freeze mode.
5. Use an FPGA that can manage system
power. Low-power, mixed-signal FPGAs and
ARM-enabled flash FPGAs enable system
power management and power islands by
monitoring and controlling the power consumption
of the battery and other components
to achieve system power efficiency.
6. Optimize for dynamic power. Look for vendors
that support software tool optimization
for low-power layout. Use FPGAs that offer
reduced core voltage and can instantly be
switched in and out of low-power modes.
7. Use flash memory save and restore capabilities.
FPGA on-board user flash memory
can enable the power-down and power-off
modes of operation.
8. Use Level 0 live-at-power-up (LAPU)
nonvolatile FPGAs, which simplify lowpower
system design. Level 0 LAPU FPGAs
quickly power up and restore the system
state from sleep mode without the need to
reload the configuration. Entering and exiting
Flash*Freeze mode is quick and easy,
which helps reduce power consumption and
increase usability.
9. Reduce total system power by using
devices with higher system integration. Look
for programmable logic that integrates power
FET control and supports simplified sleep
and standby power modes as low as 5 µW.
Additional integration of clocking resources,
the voltage regulator, and the analog-to-digital
converter removes parts from the board
and reduces total current consumption.
10. Use enable flip-flops and regional clock
resources. Limit dynamic power consumption
by utilizing FPGA power-friendly architectures
that allow the use of segmented
clocks and enable flip-flops. Also use lowpower,
high-performance serial connections
such as low-voltage differential signaling
(LVDS) with double-data-rate (DDR) registers
to minimize I/O power consumption.
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