Atualmente, os sistemas eletrônicos integrados seguem o paradigma do projeto baseado em núcleos de hardware. Além de núcleos digitais, tais sistemas podem incluir núcleos analógicos, que, neste caso, dominam os requisitos de teste, como tempo de teste e número adicional de pinos. Consequentemente, há um aumento do custo total de manufatura do dispositivo. O presente trabalho propõe o uso de técnicas de autoteste integrado (BIST) analógico, baseado no reuso de núcleos digitais presentes no mesmo sistema, com objetivo de reduzir os custos relativos ao teste do sistema. Além disso, uma estratégia satisfatória requer um adequado planejamento de teste, de forma a melhor explorar as possibilidades de teste simultâneo de mais de um núcleo e o escalonamento do teste de cada um destes, diminuindo custos associados ao teste. Adaptando uma ferramenta computacional voltada ao planejamento de sistemas compostos exclusivamente de núcleos digitais para o universo dos sistemas mistos e considerando a possibilidade do uso de BIST, pode-se avaliar o impacto da estratégia proposta em termos de tempo de teste, acréscimo de área em virtude das estruturas de teste e pinos extras. Restrições de dissipação de potência também são consideradas. Para validação das hipóteses levantadas, sistemas mistos foram descritos a partir de benchmarks industriais e acadêmicos puramente digitais, através da inclusão de núcleos analógicos. Os resultados obtidos através de simulações com a ferramenta apontam para uma redução no tempo de teste e otimização de custos de pinos e área, além da redução no custo de equipamentos automatizados de teste (ATE), para o caso de teste de produção. Com isso, uma redução no custo total do procedimento de teste de tais sistemas pode ser alcançada. / Currently, integrated electronic systems follow the core-based design paradigm. Such systems include not only digital circuits as internal blocks, but also analog circuits, which dominate test resources, such as testing time, extra pins and overhead area, thus increasing the total manufacture cost of these devices. The present work proposes the application of analog Built-in Self Test (BIST) techniques based on the reuse of available digital cores within the same integrated system, aiming to reduce the test costs of the analog cores. Moreover, a satisfactory strategy requires an adequate test planning, so that the design space is better explored. By adapting a software tool, which was originally designed for test planning of exclusively digital SOC, to consider analog cores, as well as the possibility of BIST, one can evaluate the impact of the proposed strategy in terms of test application time, area overhead due to test structures added and extra pins. Power dissipation restrictions may also be taken into account. In order to validate the hypotheses considered, mixed-signal systems are described from digital industrial and academic benchmarks, just adding analog cores. Through simulation with the adapted tool, the obtained results point to a decrease in the system test time, as well as a reduction in the cost of Automatic Test Equipment (ATE), in case of a production test. Thus, a reduction in the overall cost of the test procedure for such devices can be achieved.

Atualmente, os sistemas eletrônicos integrados seguem o paradigma do projeto baseado em núcleos de hardware. Além de núcleos digitais, tais sistemas podem incluir núcleos analógicos, que, neste caso, dominam os requisitos de teste, como tempo de teste e número adicional de pinos. Consequentemente, há um aumento do custo total de manufatura do dispositivo. O presente trabalho propõe o uso de técnicas de autoteste integrado (BIST) analógico, baseado no reuso de núcleos digitais presentes no mesmo sistema, com objetivo de reduzir os custos relativos ao teste do sistema. Além disso, uma estratégia satisfatória requer um adequado planejamento de teste, de forma a melhor explorar as possibilidades de teste simultâneo de mais de um núcleo e o escalonamento do teste de cada um destes, diminuindo custos associados ao teste. Adaptando uma ferramenta computacional voltada ao planejamento de sistemas compostos exclusivamente de núcleos digitais para o universo dos sistemas mistos e considerando a possibilidade do uso de BIST, pode-se avaliar o impacto da estratégia proposta em termos de tempo de teste, acréscimo de área em virtude das estruturas de teste e pinos extras. Restrições de dissipação de potência também são consideradas. Para validação das hipóteses levantadas, sistemas mistos foram descritos a partir de benchmarks industriais e acadêmicos puramente digitais, através da inclusão de núcleos analógicos. Os resultados obtidos através de simulações com a ferramenta apontam para uma redução no tempo de teste e otimização de custos de pinos e área, além da redução no custo de equipamentos automatizados de teste (ATE), para o caso de teste de produção. Com isso, uma redução no custo total do procedimento de teste de tais sistemas pode ser alcançada. / Currently, integrated electronic systems follow the core-based design paradigm. Such systems include not only digital circuits as internal blocks, but also analog circuits, which dominate test resources, such as testing time, extra pins and overhead area, thus increasing the total manufacture cost of these devices. The present work proposes the application of analog Built-in Self Test (BIST) techniques based on the reuse of available digital cores within the same integrated system, aiming to reduce the test costs of the analog cores. Moreover, a satisfactory strategy requires an adequate test planning, so that the design space is better explored. By adapting a software tool, which was originally designed for test planning of exclusively digital SOC, to consider analog cores, as well as the possibility of BIST, one can evaluate the impact of the proposed strategy in terms of test application time, area overhead due to test structures added and extra pins. Power dissipation restrictions may also be taken into account. In order to validate the hypotheses considered, mixed-signal systems are described from digital industrial and academic benchmarks, just adding analog cores. Through simulation with the adapted tool, the obtained results point to a decrease in the system test time, as well as a reduction in the cost of Automatic Test Equipment (ATE), in case of a production test. Thus, a reduction in the overall cost of the test procedure for such devices can be achieved.

Atualmente, os sistemas eletrônicos integrados seguem o paradigma do projeto baseado em núcleos de hardware. Além de núcleos digitais, tais sistemas podem incluir núcleos analógicos, que, neste caso, dominam os requisitos de teste, como tempo de teste e número adicional de pinos. Consequentemente, há um aumento do custo total de manufatura do dispositivo. O presente trabalho propõe o uso de técnicas de autoteste integrado (BIST) analógico, baseado no reuso de núcleos digitais presentes no mesmo sistema, com objetivo de reduzir os custos relativos ao teste do sistema. Além disso, uma estratégia satisfatória requer um adequado planejamento de teste, de forma a melhor explorar as possibilidades de teste simultâneo de mais de um núcleo e o escalonamento do teste de cada um destes, diminuindo custos associados ao teste. Adaptando uma ferramenta computacional voltada ao planejamento de sistemas compostos exclusivamente de núcleos digitais para o universo dos sistemas mistos e considerando a possibilidade do uso de BIST, pode-se avaliar o impacto da estratégia proposta em termos de tempo de teste, acréscimo de área em virtude das estruturas de teste e pinos extras. Restrições de dissipação de potência também são consideradas. Para validação das hipóteses levantadas, sistemas mistos foram descritos a partir de benchmarks industriais e acadêmicos puramente digitais, através da inclusão de núcleos analógicos. Os resultados obtidos através de simulações com a ferramenta apontam para uma redução no tempo de teste e otimização de custos de pinos e área, além da redução no custo de equipamentos automatizados de teste (ATE), para o caso de teste de produção. Com isso, uma redução no custo total do procedimento de teste de tais sistemas pode ser alcançada. / Currently, integrated electronic systems follow the core-based design paradigm. Such systems include not only digital circuits as internal blocks, but also analog circuits, which dominate test resources, such as testing time, extra pins and overhead area, thus increasing the total manufacture cost of these devices. The present work proposes the application of analog Built-in Self Test (BIST) techniques based on the reuse of available digital cores within the same integrated system, aiming to reduce the test costs of the analog cores. Moreover, a satisfactory strategy requires an adequate test planning, so that the design space is better explored. By adapting a software tool, which was originally designed for test planning of exclusively digital SOC, to consider analog cores, as well as the possibility of BIST, one can evaluate the impact of the proposed strategy in terms of test application time, area overhead due to test structures added and extra pins. Power dissipation restrictions may also be taken into account. In order to validate the hypotheses considered, mixed-signal systems are described from digital industrial and academic benchmarks, just adding analog cores. Through simulation with the adapted tool, the obtained results point to a decrease in the system test time, as well as a reduction in the cost of Automatic Test Equipment (ATE), in case of a production test. Thus, a reduction in the overall cost of the test procedure for such devices can be achieved.

Este trabalho propõe o desenvolvimento de uma metodologia para a verificação circuitos integrados de sinais mistos de uso em sistemas de comunicação que operem em modo simplex. Deseja-se aproveitar as características inversas de recepção e transmissão para otimizar o processo de verificação. Para o desenvolvimento desta metodologia de verificação, teve-se como objetivo estudar metodologias de verificação de circuitos integrados de sinais mistos existentes e sua evolução, as quais têm garantido cada vez mais a funcionalidade de circuitos integrados que são compostos por blocos analógicos e digitais. A metodologia é aplicada a um dos circuitos que compõem um sistema otimizado de transmissão de dados via satélite (Transponder para Satélite). O sistema de transmissão de dados via satélite, foco do trabalho, é composto por receptores, transmissores e conversores analógico digital e um Processador Digital de Sinais - Digital Signal Processing (DSP), todos desenvolvidos em hardware. A metodologia de verificação compreende no desenvolvimento de uma estrutura de verificação capaz de estimular os blocos digitais e analógicos com o objetivo de garantir a funcionalidade de cada um dos componentes do IP Transponder. Em uma etapa seguinte, foi possível estimular o IP Transponder de forma integrada, no que se refere aos os blocos digitais e analógicos, assim como os de transmissão e recepção. Ressalta-se ainda que todo o desenvolvimento foi realizado em alto nível, ou seja, todas as características e propriedades foram observadas utilizando-se somente simuladores para garantir a funcionalidade do circuito integrado de sinais mistos que compõe o IP Transponder para satélite. / This work proposes the development of a verification methodology, used during the verification process of a mixed signal integrated circuit, which represents a communication system operating in simplex mode. In order to optimize the verification process, reverse reception and transmission will be used. With the intention of developing our verification methodology, a study on other methodologies used for the verification of mixed signals integrated circuits and the evolution of such methodologies was carried out. The proposed methodology has been applied in an advanced circuit used to establish data transmission by satellite (Transponder for Satellite). The targeted data transmission system is composed by analog receptor and transmitter, analog to digital converters and a digital signal-processing unit, all developed in hardware. The verification methodology consists of two steps: first, the development of a verification structure that are able to stimulate digital and analog blocks in order to guarantee the functionality of each system component. In a following step, the developed verification environment provides the stimulation for all the Transponder IP (digital and analog blocks), and for transmission and reception blocks as well. The verification process development was performed in high level, meaning all the characteristics and properties has been observed using only simulators with the purpose of guarantee the functionality of the mixed signal integrated circuit that composes the satellite Transponder IP.

New circuit design techniques that accommodate lower supply voltages necessary for portable systems need to be integrated into the semiconductor intellectual property (IP) core. Systems that once worked at 3.3 V or 2.5 V now need to work at 1.8 V or lower, without causing any performance degradation. Also, the fluctuation of device characteristics caused by process variation in nanometer technologies is seen as design yield loss. The numerous parasitic effects induced by layouts, especially for high-performance and high-speed circuits, pose a problem for IC design. Lack of exact layout information during circuit sizing leads to long design iterations involving time-consuming runs of complex tools. There is a strong need for low-power, high-performance, parasitic-aware and process-variation-tolerant circuit design. This dissertation proposes methodologies and techniques to achieve variability, power, performance, and parasitic-aware circuit designs. Three approaches are proposed: the single iteration automatic approach, the hybrid Monte Carlo and design of experiments (DOE) approach, and the corner-based approach. Widely used mixed-signal circuits such as analog-to-digital converter (ADC), voltage controlled oscillator (VCO), voltage level converter and active pixel sensor (APS) have been designed at nanoscale complementary metal oxide semiconductor (CMOS) and subjected to the proposed methodologies. The effectiveness of the proposed methodologies has been demonstrated through exhaustive simulations. Apart from these methodologies, the application of dual-oxide and dual-threshold techniques at circuit level in order to minimize power and leakage is also explored.

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This work investigates energy-efficient approximate computation for solving differential equations. It extends the analog computing techniques to a new paradigm: continuous-time hybrid computation, where both analog and digital circuits operate in continuous time. In this approach, the time intervals in the digital signals contain important information. Unlike conventional synchronous digital circuits, continuous-time digital signals offer the benefits of adaptive power dissipation and no quantization noise. Two prototype chips have been fabricated in 65 nm CMOS technology and tested successfully. The first chip is capable of solving nonlinear differential equations up to 4th order, and the second chip scales up to 16th order based on the first chip. Nonlinear functions are generated by a programmable, clockless, continuous-time 8-bit hybrid architecture (ADC+SRAM+DAC). Digitally-assisted calibration is used in all analog/mixed-signal blocks. Compared to the prior art, our chips makes possible arbitrary nonlinearities and achieves 16 times lower power dissipation, thanks to technology scaling and extensive use of class-AB analog blocks. Typically, the unit achieves a computational accuracy of about 0.5% to 5% RMS, solution times from a fraction of 1 micro second to several hundred micro seconds, and total computational energy from a fraction of 1 nJ to hundreds of nJ, depending on equation details. Very significant advantages are observed in computational speed and energy (over two orders of magnitude and over one order of magnitude, respectively) compared to those obtained with a modern MSP430 microcontroller for the same RMS error.

With increased and varied performance demands, it is essential that complex multi-standard radio/systems coexist on a same chip. To have cost and performance benefits, these analog/RF systems are implemented in scaled nanometer nodes. At these nodes, the high level of variability in process variations is making the task of manufacturing high fidelity systems a challenge leading to yield and reliability issues. Hence, in the post-manufacturing phase, test and diagnosis steps are critical to identify the cause and effect of the process variations. Further, intelligent post-manufacturing tuning techniques are required to correct the effect of process variations on analog/RF systems. In this work, a die-level concurrent test and diagnosis approach using optimized measurements obtained in high volume manufacturing environment is proposed for analog/RF circuits. Such a simultaneous test and diagnosis methodology enables monitoring parametric process shifts and providing rapid feedback to the fab to minimize or prevent yield loss. In the case of devices that are continuously operating in the field, an efficient on-line diagnosis approach has been developed to perform reliability related prognosis. For advanced RF technologies such as MIMO-OFDM systems, a rapid system-level testing scheme is presented that performs concurrent testing of the multiple RF chains. Depending on the availability of the computational resources and system tuning knobs, different low-cost methodologies for post-manufacture tuning or self-healing of RF SISO/MIMO systems are developed. These include faster digital monitoring and tuning techniques, on-chip tuning techniques using digital logic that enables die-level self-tuning, and DSP-based power conscious iterative techniques for SISO/MIMO RF systems. An adaptive power-performance tuning technique is developed for those devices that have a post-manufacture power consumption value that is more than the acceptable limit. These intelligent post-manufacturing techniques result in reduced manufacturing cost, improved yield, and reliability of analog/RF systems.

Thesis (Ph. D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2005. / Kucic, Matthew, Committee Member ; Hasler, Paul, Committee Chair ; Heck, Bonnie, Committee Member ; Cressler, John, Committee Member ; Anderson, David, Committee Member. Vita. Includes bibliographical references.