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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The Killer App – Combining Embedded Processors, FPGAs and Smart Software

Cooke, Alan 11 1900 (has links)
In this paper, the benefits and advantages of combining advanced embedded processing capabilities with an FPGA based approach within a Data Acquisition Unit (DAU) are discussed. The paper begins with a discussion of some of the services and functionality that such a system enables. Basic features such as system discovery, verification, configuration and upgrade are discussed in addition to other value added services such as continuous built in test (CBIT) and embedded real-time parameter quick-look. Finally, the paper discusses some advanced services that could be deployed to these systems such as emerging communication protocols, multimedia connectivity and discovery, and advanced Machine Learning based systems diagnostics.
2

Architectural support for security and reliability in embedded processors

Ragel, Roshan Gabriel, Computer Science & Engineering, Faculty of Engineering, UNSW January 2006 (has links)
Security and reliability in processor based systems are concerns requiring adroit solutions. Security is often compromised by code injection attacks, jeopardizing even ???trusted software???. Reliability is of concern, where unintended code is executed in modern processors with ever smaller feature sizes and low voltage swings causing bit flips. Countermeasures by software-only approaches increase code size and therefore significantly reduce performance. Hardware assisted approaches use additional hardware monitors and thus incur considerably high hardware cost and have scalability problems. Considering reliability and security issues during the design of an embedded system has its advantages as this overcomes the limitations of existing solutions. The research work presented in this thesis combines two elements: one, defining a hardware software design framework for reliability and security monitoring at the granularity of micro-instructions, and two, applying this framework for real world problems. At a given time, a processor executes only a few instructions and large part of the processor is idle. Utilizing these idling hardware components by sharing them with the monitoring hardware, to perform security and reliability monitoring reduces the impact of the monitors on hardware cost. Using micro-instruction routines within the machine instructions, allows us to share most of the monitoring hardware. Therefore, our technique requires little hardware overhead in comparison to having additional hardware blocks outside the processor. This reduction in overhead is due to maximal sharing of hardware resources of the processor. Our framework is superior to software-only techniques as the monitoring routines are formed with micro-instructions and therefore reduces code size and execution time overheads, since they occur in parallel with machine instructions. This dissertation makes four significant contributions to the field of security and reliability on embedded processor research and they are: (i) proposed a security and reliability framework for embedded processors that could be included into its design phase; (ii) shown that inline (machine instruction level) monitoring will detect common security attacks (four inline monitors against common attacks cost 9.21% area and 0.67% performance, as opposed to previous work where an external monitor with two monitoring modules costs 15% area overhead); (iii) illustrated that basic block check-summing for code integrity is much simpler and efficient than currently proposed integrity violation detectors which address code injection attacks (this costs 5.03% area increase and 3.67% performance penalty with a single level control flow checking, as opposed to previous work where the area overhead is 5.59%, which needed three control flow levels of integrity checking); and (iv) shown that hardware assisted control flow checking implemented during the design of a processor is much cheaper and effective than software only approaches (this approach costs 0.24-1.47% performance and 3.59% area overheads, as opposed to previous work that costs 53.5-99.5% performance).
3

Compiler Techniques For Code Size And Power Reduction For Embedded Processors

Sarvani, V V N S 06 1900 (has links) (PDF)
No description available.
4

Memory Data Organization for Low-Energy Address Buses

DUTT, Nikil D., TAKADA, Hiroaki, TOMIYAMA, Hiroyuki 01 April 2004 (has links)
No description available.
5

Architectural support for security and reliability in embedded processors

Ragel, Roshan Gabriel, Computer Science & Engineering, Faculty of Engineering, UNSW January 2006 (has links)
Security and reliability in processor based systems are concerns requiring adroit solutions. Security is often compromised by code injection attacks, jeopardizing even ???trusted software???. Reliability is of concern, where unintended code is executed in modern processors with ever smaller feature sizes and low voltage swings causing bit flips. Countermeasures by software-only approaches increase code size and therefore significantly reduce performance. Hardware assisted approaches use additional hardware monitors and thus incur considerably high hardware cost and have scalability problems. Considering reliability and security issues during the design of an embedded system has its advantages as this overcomes the limitations of existing solutions. The research work presented in this thesis combines two elements: one, defining a hardware software design framework for reliability and security monitoring at the granularity of micro-instructions, and two, applying this framework for real world problems. At a given time, a processor executes only a few instructions and large part of the processor is idle. Utilizing these idling hardware components by sharing them with the monitoring hardware, to perform security and reliability monitoring reduces the impact of the monitors on hardware cost. Using micro-instruction routines within the machine instructions, allows us to share most of the monitoring hardware. Therefore, our technique requires little hardware overhead in comparison to having additional hardware blocks outside the processor. This reduction in overhead is due to maximal sharing of hardware resources of the processor. Our framework is superior to software-only techniques as the monitoring routines are formed with micro-instructions and therefore reduces code size and execution time overheads, since they occur in parallel with machine instructions. This dissertation makes four significant contributions to the field of security and reliability on embedded processor research and they are: (i) proposed a security and reliability framework for embedded processors that could be included into its design phase; (ii) shown that inline (machine instruction level) monitoring will detect common security attacks (four inline monitors against common attacks cost 9.21% area and 0.67% performance, as opposed to previous work where an external monitor with two monitoring modules costs 15% area overhead); (iii) illustrated that basic block check-summing for code integrity is much simpler and efficient than currently proposed integrity violation detectors which address code injection attacks (this costs 5.03% area increase and 3.67% performance penalty with a single level control flow checking, as opposed to previous work where the area overhead is 5.59%, which needed three control flow levels of integrity checking); and (iv) shown that hardware assisted control flow checking implemented during the design of a processor is much cheaper and effective than software only approaches (this approach costs 0.24-1.47% performance and 3.59% area overheads, as opposed to previous work that costs 53.5-99.5% performance).
6

Applying dual core lockstep in embedded processors to mitigate radiation induced soft errors / Aplicando dual core lockstep em processadores embarcados para mitigar falhas transientes induzidas por radiação

Oliveira, Ádria Barros de January 2017 (has links)
Os processadores embarcados operando em sistemas de segurança ou de missão crítica não podem falhar. Qualquer falha neste tipo de aplicação pode levar a consequências inaceitáveis, como risco de vida ou danos à propriedade ou ao meio ambiente. Os sistemas embarcados que operam em aplicações aeroespaciais são sucetíveis à falhas transientes induzidas por radiação. Entretanto, os efeitos de radiação também podem ser observados ao nível do solo. Falhas transientes afetam os processadores modificando os valores armazenados em elementos de memória, tais como registradores e memória de dados. Essas falhas podem levar o processador a executar incorretamente a aplicação, provocando erros na saída ou travamentos no sistema. Os avanços recentes em processadores embarcados concistem na integração de processadores hard-core e FPGAs. Tais dispositivos, comumente chamados de Sistemas-em-Chip Totalmente Programáveis (APSoCs), também são sucetíveis aos efeitos de radiação. Com objetivo de minimizar esse problema de tolerância a falhas, este trabalho apresenta um Dual-Core LockStep (DCLS) como uma técnica de tolerância para mitigar falhas induzidas por radiação que afetam processadores embarcados em APSoCs. Lockstep é um método baseado em redundância usado para detectar e corrigir falhas transientes. O DCLS proposto é implementado em um processador ARM Cortex-A9 hard-core embarcado no APSoC Zynq-7000. A eficiência da abordagem implementada foi validada tanto em aplicações executando em bare-metal como no sistema operacional FreeRTOS. Experimentos com íons pesados e emulação de falhas por injeção foram executados para analisar a sucetibilidade do sistema a inversão de bits. Os resultados obtidos mostram que a abordagem é capaz de diminuir a seção de choque do sistema com uma alta taxa de proteção. O sistema DCLS mitigou com sucesso até 78% das falhas injetadas. Otimizações de software também foram avaliadas para uma melhor compreenção dos trade-offs entre desempenho e confiabilidade. Através da análise de diferentes partições de software, observou-se que o tempo de execução de um bloco da aplicação deve ser muito maior que o tempo de verificação para que se obtenha menor impacto em desempenho. A avaliação de otimizações de compilador demonstrou que utilizar o nível O3 aumenta a vulnerabilidade da aplicação à falhas transientes. Como o O3 requer o uso de mais registradores que os otros níveis de otimização, o sistema se torna mais sucetível à falhas. Por outro lado, os resultados dos experimentos de radiação apontam que a aplicação compilada com nível O3 obtém maior Carga de Trabalho Média Entre Falhas (MWBF). Como a aplicação executa mais rápido, mais dados são computados corretamente antes da ocorrência de um erro. / The embedded processors operating in safety- or mission-critical systems are not allowed to fail. Any failure in such applications could lead to unacceptable consequences as life risk or significant damage to property or environment. Concerning faults originated by the radiation-induced soft errors, the embedded systems operating in aerospace applications are particularly susceptible. However, the radiation effects can also be observed at ground level. Soft errors affect processors by modifying values stored in memory elements, such as registers and data memory. These faults may lead the processor to execute an application incorrectly, generating output errors or leading hangs and crashes in the system. The recent advances in embedded systems concern the integration of hard-core processors and FPGAs. Such devices, called All Programmable System-on-Chip (APSoC), are also susceptible to radiation effects. Aiming to address this fault tolerance problem this work presents a Dual-Core LockStep (DCLS) as a fault tolerance technique to mitigate radiation-induced faults affecting processors embedded into APSoCs. Lockstep is a method based on redundancy used to detect and correct soft errors. The proposed DCLS is implemented in a hard-core ARM Cortex-A9 embedded into a Zynq-7000 APSoC. The approach efficiency was validated not only on applications running in baremetal but also on top of FreeRTOS systems. Heavy ions experiments and fault injection emulation were performed to analyze the system susceptibility to bit-flips. The obtained results show that the approach is able to decrease the system cross section with a high rate of protection. The DCLS system successfully mitigated up to 78% of the injected faults. Software optimizations were also evaluated to understand the trade-offs between performance and reliability better. By the analysis of different software partitions, it was observed that the execution time of an application block must to be much longer than the verification time to achieve fewer performance penalties. The compiler optimizations assessment demonstrate that using O3 level increases the application vulnerability to soft errors. Because O3 handles more registers than other optimizations, the system is more susceptible to faults. On the other hand, results from radiation experiments show that O3 level provides a higher Mean Workload Between Failures (MWBF). As the application runs faster, more data are correctly computed before an error occurrence.
7

TouchSPICE vs. ReActive-SPICE: A Human-Computer Interaction Perspective

O'Hara, Joshua Martin 01 August 2012 (has links)
Traditional SPICE simulation tools and applications of circuit theory lack real-time interaction and feedback. The goal of this thesis was to create an interactive physical environment to allow the manipulation and simulation of discrete electrical components in near-real-time while optimizing and streamlining the human-computer interaction (HCI) elements to make the user experience as positive and transparent as possible. This type of HCI and near-real-time simulation feedback would allow for the instant realization of how the parameters of each discrete component or hardware module affect the overall simulation and response of the circuit. The scope of this thesis is to research, design and develop two real-time interactive SPICE simulation tools and analyze the real-time benefits and HCI elements of both simulators, principally the user interface design itself. The first real-time interactive simulator (TouchSPICE) uses multiple embedded processors (touchscreen hardware blocks) and a host computer to build and simulate a circuit. The second real-time interactive simulator (ReActive-SPICE) uses a single host computer with integrated software to build and simulate a circuit, much like LTspice™ and PSpice™ without the real-time aspects. As part of the study, 20 students were asked to create circuits utilized in undergraduate-level labs using TouchSPICE and ReActive-SPICE for the sole purpose of providing feedback on the two user interfaces. Students were asked to complete a survey before, during and after circuit creation to provide a basis for judging the intuitiveness, efficiency and overall effectiveness of the HCIs. Conclusions based-off the surveys support the hypothesis that both TouchSPICE and ReActive-SPICE were more intuitive and overall simpler than traditional SPICE simulation tools. Feedback collected showed TouchSPICE to have a more intuitive user interface while ReActive-SPICE proved to be more efficient. ReActive-SPICE was further developed and enhanced to improve the user interface as well as the overall circuit creation and real-time simulation processes.
8

Applying dual core lockstep in embedded processors to mitigate radiation induced soft errors / Aplicando dual core lockstep em processadores embarcados para mitigar falhas transientes induzidas por radiação

Oliveira, Ádria Barros de January 2017 (has links)
Os processadores embarcados operando em sistemas de segurança ou de missão crítica não podem falhar. Qualquer falha neste tipo de aplicação pode levar a consequências inaceitáveis, como risco de vida ou danos à propriedade ou ao meio ambiente. Os sistemas embarcados que operam em aplicações aeroespaciais são sucetíveis à falhas transientes induzidas por radiação. Entretanto, os efeitos de radiação também podem ser observados ao nível do solo. Falhas transientes afetam os processadores modificando os valores armazenados em elementos de memória, tais como registradores e memória de dados. Essas falhas podem levar o processador a executar incorretamente a aplicação, provocando erros na saída ou travamentos no sistema. Os avanços recentes em processadores embarcados concistem na integração de processadores hard-core e FPGAs. Tais dispositivos, comumente chamados de Sistemas-em-Chip Totalmente Programáveis (APSoCs), também são sucetíveis aos efeitos de radiação. Com objetivo de minimizar esse problema de tolerância a falhas, este trabalho apresenta um Dual-Core LockStep (DCLS) como uma técnica de tolerância para mitigar falhas induzidas por radiação que afetam processadores embarcados em APSoCs. Lockstep é um método baseado em redundância usado para detectar e corrigir falhas transientes. O DCLS proposto é implementado em um processador ARM Cortex-A9 hard-core embarcado no APSoC Zynq-7000. A eficiência da abordagem implementada foi validada tanto em aplicações executando em bare-metal como no sistema operacional FreeRTOS. Experimentos com íons pesados e emulação de falhas por injeção foram executados para analisar a sucetibilidade do sistema a inversão de bits. Os resultados obtidos mostram que a abordagem é capaz de diminuir a seção de choque do sistema com uma alta taxa de proteção. O sistema DCLS mitigou com sucesso até 78% das falhas injetadas. Otimizações de software também foram avaliadas para uma melhor compreenção dos trade-offs entre desempenho e confiabilidade. Através da análise de diferentes partições de software, observou-se que o tempo de execução de um bloco da aplicação deve ser muito maior que o tempo de verificação para que se obtenha menor impacto em desempenho. A avaliação de otimizações de compilador demonstrou que utilizar o nível O3 aumenta a vulnerabilidade da aplicação à falhas transientes. Como o O3 requer o uso de mais registradores que os otros níveis de otimização, o sistema se torna mais sucetível à falhas. Por outro lado, os resultados dos experimentos de radiação apontam que a aplicação compilada com nível O3 obtém maior Carga de Trabalho Média Entre Falhas (MWBF). Como a aplicação executa mais rápido, mais dados são computados corretamente antes da ocorrência de um erro. / The embedded processors operating in safety- or mission-critical systems are not allowed to fail. Any failure in such applications could lead to unacceptable consequences as life risk or significant damage to property or environment. Concerning faults originated by the radiation-induced soft errors, the embedded systems operating in aerospace applications are particularly susceptible. However, the radiation effects can also be observed at ground level. Soft errors affect processors by modifying values stored in memory elements, such as registers and data memory. These faults may lead the processor to execute an application incorrectly, generating output errors or leading hangs and crashes in the system. The recent advances in embedded systems concern the integration of hard-core processors and FPGAs. Such devices, called All Programmable System-on-Chip (APSoC), are also susceptible to radiation effects. Aiming to address this fault tolerance problem this work presents a Dual-Core LockStep (DCLS) as a fault tolerance technique to mitigate radiation-induced faults affecting processors embedded into APSoCs. Lockstep is a method based on redundancy used to detect and correct soft errors. The proposed DCLS is implemented in a hard-core ARM Cortex-A9 embedded into a Zynq-7000 APSoC. The approach efficiency was validated not only on applications running in baremetal but also on top of FreeRTOS systems. Heavy ions experiments and fault injection emulation were performed to analyze the system susceptibility to bit-flips. The obtained results show that the approach is able to decrease the system cross section with a high rate of protection. The DCLS system successfully mitigated up to 78% of the injected faults. Software optimizations were also evaluated to understand the trade-offs between performance and reliability better. By the analysis of different software partitions, it was observed that the execution time of an application block must to be much longer than the verification time to achieve fewer performance penalties. The compiler optimizations assessment demonstrate that using O3 level increases the application vulnerability to soft errors. Because O3 handles more registers than other optimizations, the system is more susceptible to faults. On the other hand, results from radiation experiments show that O3 level provides a higher Mean Workload Between Failures (MWBF). As the application runs faster, more data are correctly computed before an error occurrence.
9

A Simulation Based Approach to EstimateEnergy Consumption for Embedded Processors

Liu, ke January 2015 (has links)
Embedded systems have entered a new era in which system designers have to consider more and more strict energy consumption constraints. This thesis reviewsprevious studies of the processor energy consumption estimation. Particularly, wefocus on instruction-level energy consumption for embedded processors and explorethe energy consumption model for manycore architecture in real traffic pattern.The purpose of this thesis project is to estimate energy consumption and constructan energy model using an instruction-set simulator for embedded processors. OpenVirtual Platforms (OVP) and Epiphany Single Core Simulator (ESCS) are used toobtain an instruction sequence for a given software. Then, the functionality of energyconsumption estimation is integrated into OVP.Our energy consumption estimation approach categorizes instructions in fourgroups and uses base energy cost of each category to calculate the total energyconsumption for an application that runs on Epiphany core and ARM Cortex M0.The energy consumption estimation for Epiphany core has been successfully testedby BEEBS benchmarks. Details of the derivation process, results and analysis ofenergy consumption estimation methods are provided.
10

Applying dual core lockstep in embedded processors to mitigate radiation induced soft errors / Aplicando dual core lockstep em processadores embarcados para mitigar falhas transientes induzidas por radiação

Oliveira, Ádria Barros de January 2017 (has links)
Os processadores embarcados operando em sistemas de segurança ou de missão crítica não podem falhar. Qualquer falha neste tipo de aplicação pode levar a consequências inaceitáveis, como risco de vida ou danos à propriedade ou ao meio ambiente. Os sistemas embarcados que operam em aplicações aeroespaciais são sucetíveis à falhas transientes induzidas por radiação. Entretanto, os efeitos de radiação também podem ser observados ao nível do solo. Falhas transientes afetam os processadores modificando os valores armazenados em elementos de memória, tais como registradores e memória de dados. Essas falhas podem levar o processador a executar incorretamente a aplicação, provocando erros na saída ou travamentos no sistema. Os avanços recentes em processadores embarcados concistem na integração de processadores hard-core e FPGAs. Tais dispositivos, comumente chamados de Sistemas-em-Chip Totalmente Programáveis (APSoCs), também são sucetíveis aos efeitos de radiação. Com objetivo de minimizar esse problema de tolerância a falhas, este trabalho apresenta um Dual-Core LockStep (DCLS) como uma técnica de tolerância para mitigar falhas induzidas por radiação que afetam processadores embarcados em APSoCs. Lockstep é um método baseado em redundância usado para detectar e corrigir falhas transientes. O DCLS proposto é implementado em um processador ARM Cortex-A9 hard-core embarcado no APSoC Zynq-7000. A eficiência da abordagem implementada foi validada tanto em aplicações executando em bare-metal como no sistema operacional FreeRTOS. Experimentos com íons pesados e emulação de falhas por injeção foram executados para analisar a sucetibilidade do sistema a inversão de bits. Os resultados obtidos mostram que a abordagem é capaz de diminuir a seção de choque do sistema com uma alta taxa de proteção. O sistema DCLS mitigou com sucesso até 78% das falhas injetadas. Otimizações de software também foram avaliadas para uma melhor compreenção dos trade-offs entre desempenho e confiabilidade. Através da análise de diferentes partições de software, observou-se que o tempo de execução de um bloco da aplicação deve ser muito maior que o tempo de verificação para que se obtenha menor impacto em desempenho. A avaliação de otimizações de compilador demonstrou que utilizar o nível O3 aumenta a vulnerabilidade da aplicação à falhas transientes. Como o O3 requer o uso de mais registradores que os otros níveis de otimização, o sistema se torna mais sucetível à falhas. Por outro lado, os resultados dos experimentos de radiação apontam que a aplicação compilada com nível O3 obtém maior Carga de Trabalho Média Entre Falhas (MWBF). Como a aplicação executa mais rápido, mais dados são computados corretamente antes da ocorrência de um erro. / The embedded processors operating in safety- or mission-critical systems are not allowed to fail. Any failure in such applications could lead to unacceptable consequences as life risk or significant damage to property or environment. Concerning faults originated by the radiation-induced soft errors, the embedded systems operating in aerospace applications are particularly susceptible. However, the radiation effects can also be observed at ground level. Soft errors affect processors by modifying values stored in memory elements, such as registers and data memory. These faults may lead the processor to execute an application incorrectly, generating output errors or leading hangs and crashes in the system. The recent advances in embedded systems concern the integration of hard-core processors and FPGAs. Such devices, called All Programmable System-on-Chip (APSoC), are also susceptible to radiation effects. Aiming to address this fault tolerance problem this work presents a Dual-Core LockStep (DCLS) as a fault tolerance technique to mitigate radiation-induced faults affecting processors embedded into APSoCs. Lockstep is a method based on redundancy used to detect and correct soft errors. The proposed DCLS is implemented in a hard-core ARM Cortex-A9 embedded into a Zynq-7000 APSoC. The approach efficiency was validated not only on applications running in baremetal but also on top of FreeRTOS systems. Heavy ions experiments and fault injection emulation were performed to analyze the system susceptibility to bit-flips. The obtained results show that the approach is able to decrease the system cross section with a high rate of protection. The DCLS system successfully mitigated up to 78% of the injected faults. Software optimizations were also evaluated to understand the trade-offs between performance and reliability better. By the analysis of different software partitions, it was observed that the execution time of an application block must to be much longer than the verification time to achieve fewer performance penalties. The compiler optimizations assessment demonstrate that using O3 level increases the application vulnerability to soft errors. Because O3 handles more registers than other optimizations, the system is more susceptible to faults. On the other hand, results from radiation experiments show that O3 level provides a higher Mean Workload Between Failures (MWBF). As the application runs faster, more data are correctly computed before an error occurrence.

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