Near/Sub-Threshold Circuits and Approximate Computing: The Perfect Combination for Ultra-Low-Power Systems

While sub/near-threshold design offers the minimal power and energy consumption, such approach strongly deteriorates circuit performances and robustness against PVT (process/voltage/temperature) variations, leading to gigantic speed penalties and large silicon areas. Inexact and approximate circuit design can address these issues by trading calculation accuracy for better silicon area, circuit speed and even better power consumption. This paper reviews and proposes improvements for two approximate computing techniques applicable to arithmetic circuits: gate-level pruning and carry speculation. A critical study is then carried out considering several error metrics, and for the first time, those techniques are combined to produce approximate adders showing even higher gains at similar error levels. It is then shown that those techniques can be applied to a sub-threshold library to mitigate the large variability.


Published in:
VLSI (ISVLSI), 2015 IEEE Computer Society Annual Symposium on, 476 - 480
Presented at:
2015 IEEE Computer Society Annual Symposium on VLSI (ISVLSI), Montpellier, france, 8-10 July 2015
Year:
2015
Publisher:
IEEE
ISBN:
978-1-4799-8718-4
Keywords:
Laboratories:




 Record created 2015-11-05, last modified 2018-03-17

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