TY - JOUR

T1 - Coherent Design of Hybrid Approximate Adders: Unified Design Framework and Metrics

AU - Najafi, A.

AU - Weißbrich, M.

AU - Payá-Vayá, G.

AU - Garcia-Ortiz, A.

N1 - Funding information: Manuscript received January 5, 2018; revised April 1, 2018; accepted April 29, 2018. Date of publication May 4, 2018; date of current version December 11, 2018. This work was supported by the German Research Foundation under Project GA 763/4-1. This paper was recommended by Guest Editor V. De. (Corresponding author: Ardalan Najafi.) A. Najafi and A. Garcia-Ortiz are with the Institute of Electrodynamics and Microelectronics, University of Bremen, 28359 Bremen, Germany (e-mail: ardalan@item.uni-bremen.de; agarcia@item.uni-bremen.de).

PY - 2018/12

Y1 - 2018/12

N2 - Numerous approximate adders have been proposed in the literature in response to the languishing benefits of technology scaling. However, they have been obtained with an ad-hoc and non-systematic methodology which does not fully exploit the design space possibilities. This paper provides a conceptual framework for the systematic design of approximate adders, including hybrid and non-equally segmented approaches as well as more robust error metrics. The framework discriminates the scenarios, where approximate processing does not provide significant benefits from those where it does; in this later case, it aids to obtain optimal configurations for the adders. Experimental results with a commercial technology assess the significant improvements of our systematic approach. Furthermore, a case study with a processor enhanced with an approximate accelerator highlights the usability of the methods.

AB - Numerous approximate adders have been proposed in the literature in response to the languishing benefits of technology scaling. However, they have been obtained with an ad-hoc and non-systematic methodology which does not fully exploit the design space possibilities. This paper provides a conceptual framework for the systematic design of approximate adders, including hybrid and non-equally segmented approaches as well as more robust error metrics. The framework discriminates the scenarios, where approximate processing does not provide significant benefits from those where it does; in this later case, it aids to obtain optimal configurations for the adders. Experimental results with a commercial technology assess the significant improvements of our systematic approach. Furthermore, a case study with a processor enhanced with an approximate accelerator highlights the usability of the methods.

KW - Approximate adders

KW - Automatic design framework

KW - Computer vision

KW - Error metrics

KW - Generic template

UR - http://www.scopus.com/inward/record.url?scp=85046429017&partnerID=8YFLogxK

U2 - 10.1109/jetcas.2018.2833284

DO - 10.1109/jetcas.2018.2833284

M3 - Article

VL - 8

SP - 736

EP - 745

JO - IEEE Journal on Emerging and Selected Topics in Circuits and Systems

JF - IEEE Journal on Emerging and Selected Topics in Circuits and Systems

SN - 2156-3357

IS - 4

M1 - 8354693

ER -