TOKYO, June
27, 2008
- NEC Corporation today announced the development
of an important new technology that is able to "visualize" the thermal
distribution and reduce the power consumption of LSI, which has become
an increasingly serious challenge as the miniaturization of LSI
continues to advance. These latest developments have been demonstrated
through NEC's SX-9 super computer.
The new technology features scores of thermal sensors, 1/10 the sizeof
previously available sensors, which are internally located
throughout the LSI, and convert temperature changes into digital
signals that enable the heat distribution of the LSI to be "visualized"
in real-time. The miniaturization of the thermal sensors enables them
to be widely distributed throughout the LSI, which increases the
precision of measurements.
Thanks to the development of technology that allows thermaldistribution
to be "visualized," independent local measures can be
taken on specific regions of an LSI chip in order to control heat.
This allows tasks to be delegated to less active areas of a chip,
which reduces the total amount of electricity required for operations
and lessens the environmental impact. Specifically, the widespread use
of devices equipped with this latest technology and LSI multi-cores
will result in greater optimization of clock-frequency, data
processing and voltage levels, which will deliver a 20 - 50% reduction
in the power consumption of LSI devices (note *1).
Please see below for detail on the primary features of this
latest technology.
1) Increasing thermal sensors within LSIThe latest thermal sensors are
able to calculate temperatures by
measuring leakage currents from transistors through miniature
conversion circuits that convert leakage currents to digital signals.
The new sensors are 1/10 the size of conventional diode based sensors
and they are equipped with circuits that detect and convert leakage
currents to digital signals. Even if the power voltage changes while
the LSI is operating, measurements remain highly accurate and errors
are contained to less than 2 degrees Celsius. Moreover, only a
relatively small number of the previously available, larger, thermal
sensors could be placed within an LSI. Scores of the new miniature
sensors may now be placed within an LSI in order to provide an
accurate real-time "visualization" of a device's heat distribution.
2) Correction of temperature miscalculations caused by
manufacturing variations
A conversion equation has been developed in order to measure the
volume of an active LSI's leakage current and to convert it into a
temperature. Temperature miscalculations may be corrected through new
technologies that take one measure of each thermal sensor's leakage
current at room temperature, a process that formerly required multiple
measurements, to improve the accuracy of results. Until now, LSI were
limited to thermal sensors that delivered temperature measurements
whose margin of error exceeded several tens of degrees Celsius. The
latest sensors have been dramatically improved, and now provide
temperature measurements that are within 3 degrees Celsius of accuracy.
Even though variations in the manufacturing of LSI can cause leakage
current differences that are as much as 100 times different from one
another, the latest sensors continue to deliver accurate readings.
Looking forward, as LSI perform more difficult procedures and
chipsequipped with large volume multi-core capabilities are used more
often,
both heat distribution and active core regions will continuously
change. These conditions require the accurate calculation of high
temperature areas, which is accomplished through chips outfitted with
a large quantity of thermal sensors that are able to deliver
temperature readings in real-time. Conventional thermal sensors were
oversized and cumbersome, which prevented chips from being equipped
with a large number of them, and inhibited a chip's ability to
reliably manage temperature issues.
The high temperature of an LSI's internal regions has also brought
ondistrust in the deteriorating performance of transistors and wire
connections. Leakage currents from LSI that rise more than 40 degrees
Celsius have increased by more than 10 times, which has caused the
lifetime of transistors and wiring to decrease by approximately 50%.
The above factors have drawn particular attention to the importance of
improving the temperature management of LSI in order to reduce
electric power consumption and improve reliability.
For example, data center temperatures can now be better
regulatedthrough continuous real-time monitoring of the center's
temperature
distribution. This enables specific sections to be intensively
ventilated or certain tasks to be designated to separate servers for
processing. The high temperature management technologies not only help
secure greater reliability of machinery, they also improve the
effectiveness of cooling systems, which results in a more dependable
and ecologically friendly product.
The technologies that allow an LSI's temperature distribution to
be"visualized" are considered an essential part of the development of a
"Data Center On Chip" (note *2) that will enable LSI of the future to
perform similar functions as the data centers of today.
NEC will continue to pursue development of technologies that assist
inthe resolution of environmental challenges. Accordingly, these latest
technologies promise to become an essential element to the improved
performance of LSI, as well as the devices appearing in vehicles,
digital AVs, networks, servers and more, which are becoming
increasingly dependent on the reliability and environmentally friendly
benefits of LSI.
NEC plans to formally announce these latest achievements on June 20
atthe "2008 Symposia on VLSI Circuits," held in Hawaii, USA from
June 18 - 20.
(note *1)
Based on calculations performed by NEC on 2-core processing
and power
voltage control
(note *2)
Data Center On Chip: Chips reinforced with multi-core
technologies
that are capable of the same processing as today's data centers (based
on anticipated future innovations within LSI integration and chip
development).
About NEC Corporation
NEC Corporation (TSE: 6701) is one of the world's
leading providers of
Internet, broadband network and enterprise business solutions
dedicated to meeting the specialized needs of its diverse and global
base of customers. NEC delivers tailored solutions in the key fields
of computer, networking and electron devices, by integrating its
technical strengths in IT and Networks, and by providing advanced
semiconductor solutions through NEC Electronics Corporation.
The NEC Group employs more than 150,000 people worldwide. For
additional information, please visit the NEC home page at: www.nec.com
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