Application of the FPAA to Sample Input Signal for Laboratory Exercise: Pulse Amplitude Modulation

This paper presents exemplary exercise on the fundamentals of signal processing course which is offered for second year bachelor level students. Application of Field Programmable Analog Array (FPAA) for pulse amplitude modulation (PAM) exercise is described with signal processing laboratory. There are presented two methods for implementing PAM modulation and demodulation technique in FPAA module. Example configuration files are available form Authors’ web site

Can my chip behave like my brain?

Many decades ago, Carver Mead established the foundations of neuromorphic systems. Neuromorphic systems are analog circuits that emulate biology. These circuits utilize subthreshold dynamics of CMOS transistors to mimic the behavior of neurons. The objective is to not only simulate the human brain, but also to build useful applications using these bio-inspired circuits for ultra low power speech processing, image processing, and robotics. This can be achieved using reconfigurable hardware, like field programmable analog arrays (FPAAs), which enable configuring different applications on a cross platform system. As digital systems saturate in terms of power efficiency, this alternate approach has the potential to improve computational efficiency by approximately eight orders of magnitude. These systems, which include analog, digital, and neuromorphic elements combine to result in a very powerful reconfigurable processing machine.Ph.D

Teaching and learning Operational Amplifiers using a reconfigurable and expandable kit

Operational Amplifiers (OpAmps) are one of the most important integrated circuits in the area of electronics. These type of devices are widely adopted in the area since they allow the design of simple and/or complex analogue circuits without many efforts. It is therefore fundamental to create innovative educational solutions to facilitate their teaching and learning, and in particular the inclusion of more experimental work in a course curricula. For this purpose, it was designed and implemented a reconfigurable and expandable kit to teach and learn electronic circuits based on the OpAmp uA741. The kit comprises a software application and a hardware platform. The software application allows the simulation and the reconfiguration of real electronic circuits based on the OpAmp uA741 included in the hardware platform. For measuring and/or applying signals to a particular reconfigured circuit, users may establish automatic connections. In this paper it is described the features and functionalities provided by the kit, and an overview about the OpAmp uA741. At the end, some teachers’ opinions about their perceptions concerning a possible adoption of the kit in a real educational scenario are presented.N/

Mixed Signal Integrated Circuit Design for Custom Sensor Interfacing

Low-power analog integrated circuits (ICs) can be utilized at the interface between an analog sensor and a digital system\u27s input to decrease power consumption, increase system accuracy, perform signal processing, and make the necessary adjustments for compatibility between the two devices. This interfacing has typically been done with custom integrated solutions, but advancements in floating-gate technologies have made reconfigurable analog ICs a competitive option. Whether the solution is a custom design or built from a reconfigurable system, digital peripheral circuits are needed to configure their operation for these analog circuits to work with the best accuracy.;Using an analog IC as a front end signal processor between an analog sensor and wireless sensor mote can greatly decrease battery consumption. Processing in the digital domain requires more power than when done on an analog system. An Analog Signal Processor (ASP) can allow the digital wireless mote to remain in sleep mode while the ASP is always listening for an important event. Once this event occurs, the ASP will wake the wireless mote, allowing it to record the event and send radio transmissions if necessary. As most wireless sensor networks employ the use of batteries as a power source, an energy harvesting system in addition to an ASP can be used to further supplement this battery consumption.;This thesis documents the development of mixed-signal integrated circuits for use as interfaces between analog sensors and digital Wireless Sensor Networks (WSNs). The following work outlines, as well as shows the results, of development for sensor interfacing utilizing both custom mixed signal integrated circuits as well as a Field Programmable Analog Array (FPAA) for post fabrication customization. An Analog Signal Processor (ASP) has been used in an Acoustic Vehicle Classification system. To keep these interfacing methods low power, a prototype energy harvesting system using commercial-off-the-shelf (COTS) devices is detailed which has led to the design of a fully integrated solution

An Alternative Way of Teaching Operational Amplifiers Using a Reconfigurable and Expandable Kit

Early on, students must develop competences by implementing simple or complex electronic circuits with Operational Amplifiers (OpAmps). Traditionally, these skills were mainly developed in laboratory classes, but technology allows us to explore other and complementary ways of aiding students in this achievement. This paper presents a contribution to improve the way OpAmps are included in electronic engineering courses’ curricula. A reconfigurable and expandable kit to teach electronic circuits based on the OpAmp uA741 was designed and implemented. This kit comprises a software application locally interfaced with a hardware platform capable of running in a PC. This platform includes a circuit with the OpAmp uA741 able to reconfigure according to a set of parameters defined by a software application. Its reconfiguration capability also enables the establishment of automatic connections for measuring and for applying signals to a reconfigured circuit, plus the ability to simulate the same or other OpAmp-based circuits. This paper provides an overview about the OpAmp uA741 and its relevance in engineering education. After presenting the kit and make some considerations for its improvement, at the end a brief discussion about its implementation in education according to specific educational strategies and methodologies are provided.This work was supported in part by the Fundação para a Ciência e Tecnologia under Grant FCT-UID-EQU-04730-2013info:eu-repo/semantics/publishedVersio

Circuit Design and Routing For Field Programmable Analog Arrays

Accurate, low-cost, rapid-prototyping techniques for analog circuits have been a long awaited dream for analog designers. However, due to the inherent nature of analog system, design automation in analog domain is very difficult to realize, and field programmable analog arrays (FPAA) have not achieved the same success as FPGAs in the digital domain. This results from several factors, including the lack of supporting CAD tools, small circuit density, low speed and significant parasitic effect from the fixed routing wires. These factors are all related to each other, making the design of a high performance FPAA a multi-dimension problem. Among others, a critical reason behind these difficulties is the non-ideal programming technology, which contributes a large portion of parasitics into the sensitive analog system, thus degrades the system performance. This work is trying to attack these difficulties with development of a laser field programmable analog array (LFPAA). There are two parts of work involved, routing for FPAA and analog IC building block design. To facilitate the router development and provide a platform for FPAA application development, a generic arrayed based FPAA architecture and a flexible CAB topology were proposed. The routing algorithm was based on a modified and improved pathfinder negotiated routing algorithm, and was implemented in C for a prototype FPAA. The parasitic constraints for performance analog routing were also investigated and solutions were proposed. In the area of analog circuit design, a novel differential difference op amp was invented as the core building block. Two bandgap circuits including a low voltage version were developed to generate a stable reference voltage for the FPAA. Based on the proposed FPAA architecture, several application examples were demonstrated. The results show the flexible functionality of the FPAA. Moreover, various laser Makelink test structures were studied on different CMOS processes and BiCMOS copper process. Laser Makelink proves to be a powerful programming technology for analog IC design. A novel laser Makelink trimming method was invented to reduce the op amp offset. The application of using laser Makelink to reconfigure the analog circuit blocks was presented

Intrinsically Evolvable Artificial Neural Networks

Dedicated hardware implementations of neural networks promise to provide faster, lower power operation when compared to software implementations executing on processors. Unfortunately, most custom hardware implementations do not support intrinsic training of these networks on-chip. The training is typically done using offline software simulations and the obtained network is synthesized and targeted to the hardware offline. The FPGA design presented here facilitates on-chip intrinsic training of artificial neural networks. Block-based neural networks (BbNN), the type of artificial neural networks implemented here, are grid-based networks neuron blocks. These networks are trained using genetic algorithms to simultaneously optimize the network structure and the internal synaptic parameters. The design supports online structure and parameter updates, and is an intrinsically evolvable BbNN platform supporting functional-level hardware evolution. Functional-level evolvable hardware (EHW) uses evolutionary algorithms to evolve interconnections and internal parameters of functional modules in reconfigurable computing systems such as FPGAs. Functional modules can be any hardware modules such as multipliers, adders, and trigonometric functions. In the implementation presented, the functional module is a neuron block. The designed platform is suitable for applications in dynamic environments, and can be adapted and retrained online. The online training capability has been demonstrated using a case study. A performance characterization model for RC implementations of BbNNs has also been presented

A Parallel Programmer for Non-Volatile Analog Memory Arrays

Since their introduction in 1967, floating-gate transistors have enjoyed widespread success as non-volatile digital memory elements in EEPROM and flash memory. In recent decades, however, a renewed interest in floating-gate transistors has focused on their viability as non-volatile analog memory, as well as programmable voltage and current sources. They have been used extensively in this capacity to solve traditional problems associated with analog circuit design, such as to correct for fabrication mismatch, to reduce comparator offset, and for amplifier auto-zeroing. They have also been used to implement adaptive circuits, learning systems, and reconfigurable systems. Despite these applications, their proliferation has been limited by complex programming procedures, which typically require high-precision test equipment and intimate knowledge of the programmer circuit to perform.;This work strives to alleviate this limitation by presenting an improved method for fast and accurate programming of floating-gate transistors. This novel programming circuit uses a digital-to-analog converter and an array of sample-and-hold circuits to facilitate fast parallel programming of floating-gate memory arrays and eliminate the need for high accuracy voltage sources. Additionally, this circuit employs a serial peripheral interface which digitizes control of the programmer, simplifying the programming procedure and enabling the implementation of software applications that obscure programming complexity from the end user. The efficient and simple parallel programming system was fabricated in a 0.5?m standard CMOS process and will be used to demonstrate the effectiveness of this new method

Studies and implementations of chaotic dynamics using reconfigurable analog devices

Orientador: Marconi Kolm MadridDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de ComputaçãoResumo: Este trabalho teve como principal objetivo estudar a tecnologia baseada em dispositivos Field Programmable Analog Arrays (FPAAs) e identificar os benef'icios quanto ao seu uso em aplicações de identificação de fenômenos inerentes aos sistemas dinâmicos não-lineares, tais como bifurcações e caos. Esses dispositivos permitem que diferentes tipos de circuitos possam ser implementados sem a necessidade de alteração da topologia do circuito, ou seja, existe a possibilidade de que os sistemas possam ser reconfigurados em tempo de execução à medida que novas alterações sejam necessárias. Com base na Teoria do Caos e na Teoria de Sistemas de Controle, foi implementado o sistema conhecido como Circuito de Chua, que serviu para demonstrar os ganhos que se podem obter com o uso da abordagem proposta quando aplicada ao estudo de sistemas dinâmicos operando no caos em relação às técnicas consideradas mais convencionais. Resultados obtidos pela análise de séries temporais de sinais adquiridos, comprovam a grande eficiência dessa abordagem quanto ao tempo de desenvolvimento e ao tempo para a obtenção dos resultados em comparação com implementações de modelos dinâmicos bastante conhecidos na literatura em relação às implementações dos mesmos em computadoresAbstract: This work had as main objective to study the technology based on Field Programmable Analog Arrays (FPAAs) devices and to identify the benefits to use these devices in applications of identification of inherent phenomena to the nonlinear dynamic systems as bifurcations and chaos. These devices allow that different types of circuits can be implemented without the necessity of alteration of the topology of the circuit, that is, the systems implemented in the FPAA can be reconfigured in execution when new alterations are necessary. On the basis of the Chaos Theory and in the Control Systems Theory, was implemented the system known as Chua¿s Circuit which served to demonstrate the profits that can be gotten with the use of the boarding proposal when applied to the study of dynamic systems operating in chaos in relation to the considered techniques conventional. Gotten results, for the analysis of time series of acquired signals, prove the great efficiency of this boarding in the time of development and the time for obtain the results when comparing implementations of dynamic models sufficiently known in literature in relation with the implementations of the same ones in digital computersMestradoAutomaçãoMestre em Engenharia Elétric