Leonardo Pinto dos Santos

Accelerated FPGA repair through shifted scrubbing

As critical systems make more and more use of high performance FPGAs, several reliability aspects of these devices come into play. Whenever SRAM-based FPGAs are used, upsets in the configuration memory become a major dependability threat, and must be removed as soon as possible. This is usually accomplished through a process called scrubbing. The traditional scrubbing technique, however, suffers from high energy costs and a long mean time to repair (MTTR). In this work we propose a novel approach to minimize these drawbacks through a triggered shifted scrubbing procedure. The proposed technique exploits the non-uniform distribution of critical bits in the configuration memory of the device to reduce the repair time. It provides an average MTTR reduction of 30% without any changes in the circuit implemented in the FPGA when compared to previous works.

Scrubbing unit repositioning for fast error repair in FPGAs

Field Programmable Gate Arrays (FPGAs) are very successful platforms that rely on large configuration memories to store the circuit functions required by users. Faults affecting such memories are a major dependability threat for these devices, and the applicability of FPGAs on critical systems depends on efficient means to mitigate their effects. The main means to effectively remove such faults, namely configuration scrubbing, consists in rewriting the desired contents of this memory and suffers from high power consumption and a long mean time to repair (MTTR). In this work we propose Scrubbing Unit Repositioning for Fast Error Repair (SURFER), a novel approach to exploit partial dynamic reconfiguration coupled with fine-grained redundancy to greatly reduce the MTTR for FPGAs subject to upsets in their configuration memories.

Low Cost Dynamic Scrubbing for Real-Time Systems

Field-programmable gate arrays FPGAs offer several desirable characteristics, such as high speed and flexibility. These characteristics come at a cost, however, as high performance FPGAs use SRAM-based configuration memories that are susceptible to Single Event Upsets SEUs. The conventional approach is to use some form of redundancy with a periodic scrubbing of the configuration memory, thus removing accumulated SEUs. In this paper we propose a novel approach to scrubbing FPGAs in real-time systems, by using diagnostic information based only on the primary outputs of the circuits, in the form of a coarse-grained DMR, and a specialized scrubbing mechanism to avoid missing real-time deadlines.

Jean Piaget E A Construção De Maquetes: Um Olhar Para A Educação Geográfica / Jean Piaget And The Construction Of Models: A Look At The Geographical Education

RESUMO O seguinte trabalho se pauta em reflexoes sobre a potencialidade da construcao de maquetes para o ensino da Geografia, tendo neste objeto o ponto de partida para possiveis desequilibrios mentais por parte dos educandos. Utilizamos como metodologia para sua confeccao o estudo de Costella (2003) que divide sua construcao em oito etapas distintas (contextualizacao; projeto; construcao; croqui; legenda; relatorio; conclusao; exposicao). Temos ainda em Jean Piaget, a base para que sua construcao seja abalizada em um ambiente pautado no dialogo entre os estudantes. Pensamos neste instrumento metodologico como o ponto de inicio e meio para o processo de construcao do conhecimento e nao o ponto final deste processo. A maquete se mostra neste trabalho como um recurso didatico que leva a compreensao de saberes geograficos, levando ao modelo tridimensional do espaco geografico as distintas relacoes sociais que vivemos como seres humanos convivendo no coletivo. Palavras-chave: Ensino de Geografia. Geografia. Maquetes. Jean Piaget. ABSTRACT The following work is guided reflections on the potential construction of models for teaching Geography, and this object the starting point for possible mental health problems by the students. Used as a methodology for making the study of Costella (2003) dividing its construction in eight distinct stages (contextualization; design, construction, sketch, legend; report; conclusion; exposure). We have yet to Jean Piaget, the basis for its construction is authoritative in a guided environment in dialogue between students. We think this methodological tool as the starting point and a half to the process of knowledge construction and not the end point of this process. The model shown here as an educational resource that leads to understanding of geographic knowledge, leading to the three-dimensional model of the geographical space the different social relations that we live as human beings living in the collective. Keywords: Geography Teaching. Geography. Model. Jean Piaget.