Departamento de Física
URI permanente desta comunidadehttps://repositorio.fei.edu.br/handle/FEI/785
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2 resultados
Resultados da Pesquisa
- Evaluating the Reliability of Different Voting Schemes for Fault Tolerant Approximate Systems(2023-06-20) BALEN, T. R.; GONZALEZ, C. J.; OLIVEIRA, I. F. V.; DA ROSA JR. L. S.; SOARES, R. I.; SCHVITTZ, R. B.; ADDED, N.; MACCHIONE, E. L. A.; AGUIAR, V. A. P.; Marcilei Aparecida Guazzelli; MEDINA, N. H.; BUTZEN, P. F.© 2023, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.This work presents a study on the reliability of voters for approximate fault tolerant systems in the context of single event effects and electromagnetic interference. A first case study analyses different topologies of single-bit majority voters for logic circuits employing fault injection by simulation. In these simulations, an analysis is first performed to identify the critical diffusion areas of the physical implementation according to the voter input vector. Additionally, as a second case study, practical heavy ion experiments on different architectures of software-based approximate voters for mixed-signal applications are also presented, and the cross section of each voter is evaluated. The system comprising the voters was irradiated in two distinct experiments with an 16O ion beam, producing an effective LET at the active region of 5.5 MeV/mg/cm 2 . As a complementary study, a conducted electromagnetic interference injection was also performed, considering two distinct voting schemes. Results of the case-studies allow identifying the most tolerant voter architectures (among the studied ones) for approximate computing applications under single event effects and electromagnetic interference.
- Failure Mechanism and Sampling Frequency Dependency on TID Response of SAR ADCs(2021) GONZALEZ, C. J.; COSTA, B. L.; MACHADO, D. N.; VAZ, R. G.; BOAS, A. C. V.; GONÇALEZ, O. L.; PUCHNER, H.; KASTENSMIDT, F. L.; MEDINA, N. H.; Marcilei Aparecida Guazzelli; BALEN, T. R.© 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.This paper describes the main failure mechanism of charge redistribution Successive Approximation Register (SAR) Analog-to-Digital Converters (ADCs) under radiation. Results of two different radiation experiments (gamma and X-ray) each considering two identical 130nm, 8-bit SAR ADCs, operating with distinct sampling rates, showed that lower sampling frequencies cause the converters to fail at lower accumulated dose, while increasing the sampling frequency increases the converters robustness to radiation. A SPICE model of a SAR ADC is used to simulate radiation induced leakage effects, considering the same technology node and operating conditions of the tested converters. A very good agreement between simulation results and gamma irradiation experimental data allows us to explain the main failure mechanism, which is related to leakage in switches connected to the programmable capacitor array of the internal DAC of the converter.