Approximate computing is emerging as a new paradigm to improve digital circuit performance by relaxing the requirement of performing exact calculations. Approximate adders rely on the idea that for uniformly distributed inputs, long carry-propagation chains are rarely activated. Unfortunately, however, the above assumption on input signal statistics is not always verified; in this paper we focus on the case (often encountered in practical signal processing applications) when the inputs have a Gaussian distribution. We show that for Gaussian inputs the error probability of previously proposed approximate adders approaches 25% for low sigma values, which is much larger than the uniform case. On the basis of this analysis, we propose an approximate adder with a correction circuit that drastically reduces the error rate for Gaussian distributed operand s. In order to investigate the performance of our approach in a real application, simulated results for a simple audio processing system are reported. Implementation results in 65nm technology are also presented.

Approximate adder with output correction for error tolerant applications and Gaussian distributed inputs / Esposito, Darjn; Castellano, Gerardo; DE CARO, Davide; Napoli, Ettore; Petra, Nicola; Strollo, ANTONIO GIUSEPPE MARIA. - 2016-:(2016), pp. 1970-1973. (Intervento presentato al convegno 2016 IEEE International Symposium on Circuits and Systems, ISCAS 2016 tenutosi a Montreal's Sheraton Centre, can nel 2016) [10.1109/ISCAS.2016.7538961].

Approximate adder with output correction for error tolerant applications and Gaussian distributed inputs

ESPOSITO, DARJN;CASTELLANO, GERARDO;DE CARO, Davide;NAPOLI, ETTORE;PETRA, NICOLA;STROLLO, ANTONIO GIUSEPPE MARIA
2016

Abstract

Approximate computing is emerging as a new paradigm to improve digital circuit performance by relaxing the requirement of performing exact calculations. Approximate adders rely on the idea that for uniformly distributed inputs, long carry-propagation chains are rarely activated. Unfortunately, however, the above assumption on input signal statistics is not always verified; in this paper we focus on the case (often encountered in practical signal processing applications) when the inputs have a Gaussian distribution. We show that for Gaussian inputs the error probability of previously proposed approximate adders approaches 25% for low sigma values, which is much larger than the uniform case. On the basis of this analysis, we propose an approximate adder with a correction circuit that drastically reduces the error rate for Gaussian distributed operand s. In order to investigate the performance of our approach in a real application, simulated results for a simple audio processing system are reported. Implementation results in 65nm technology are also presented.
2016
9781479953400
9781479953400
Approximate adder with output correction for error tolerant applications and Gaussian distributed inputs / Esposito, Darjn; Castellano, Gerardo; DE CARO, Davide; Napoli, Ettore; Petra, Nicola; Strollo, ANTONIO GIUSEPPE MARIA. - 2016-:(2016), pp. 1970-1973. (Intervento presentato al convegno 2016 IEEE International Symposium on Circuits and Systems, ISCAS 2016 tenutosi a Montreal's Sheraton Centre, can nel 2016) [10.1109/ISCAS.2016.7538961].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11588/643020
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