Analog signal processing on a reconfigurable platform

The Cooperative Analog/Digital Signal Processing (CADSP) research group's approach to signal processing is to see what opportunities lie in adjusting the line between what is traditionally computed in digital and what can be done in analog. By allowing more computation to be done in analog, we can take advantage of its low power, continuous domain operation, and parallel capabilities. One setback keeping Analog Signal Processing (ASP) from achieving more wide-spread use, however, is its lack of programmability. The design cycle for a typical analog system often involves several iterations of the fabrication step, which is labor intensive, time consuming, and expensive. These costs in both time and money reduce the likelihood that engineers will consider an analog solution. With CADSP's development of a reconfigurable analog platform, a Field-Programmable Analog Array (FPAA), it has become much more practical for systems to incorporate processing in the analog domain. In this Thesis, I present an entire chain of tools that allow one to design simply at the system block level and then compile that design onto analog hardware. This tool chain uses the Simulink design environment and a custom library of blocks to create analog systems. I also present several of these ASP blocks, covering a broad range of functions from matrix computation to interfacing. In addition to these tools and blocks, the most recent FPAA architectures are discussed. These include the latest RASP general-purpose FPAAs as well as an adapted version geared toward high-speed applications.M.S.Committee Chair: Hasler, Paul; Committee Member: Anderson, David; Committee Member: Ghovanloo, Maysa

A coordinated approach to reconfigurable analog signal processing

The purpose of this research is to create a solid framework for embedded system design with field-programmable analog arrays (FPAAs). To achieve this goal, we've created a unified approach to the three phases of FPAA system design: (1) the hardware architecture; (2) the circuit design and modeling; and (3) the high-level software tools. First, we describe innovations to the reconfigurable analog hardware that enable advanced signal processing and integration into embedded systems. We introduce the multiple-input translinear element (MITE) FPAA and the dynamically-reconfigurable RASP 2.9v FPAA, which was designed explicitly for interfacing with external digital systems. This compatibility creates a streamlined workflow for dropping the FPAA hardware into mixed-signal embedded systems. The second phase, algorithm analysis and modeling, is important to create a useful and reliable library of components for the system designer. We discuss the concept and procedure of analog abstraction that empowers non-circuit design engineers to take full advantage of analog techniques. We use the analog vector-matrix multiplier as an example for a detailed discussion on computational analog analysis and system mapping to the FPAA. Lastly, we describe high-level software tools, which are an absolute necessity for the design of large systems due to the size and complexity of modern FPAAs. We describe the Sim2Spice tool, which allows system designers to develop signal processing systems in the Simulink environment. The tool then compiles the system to the FPAA hardware. By coordinating the development of these three phases, we've created a solid unified framework that empowers engineers to utilize FPAAs.Ph.D

Genetic Association Study Of Exfoliation Syndrome Identifies A Protective Rare Variant At Loxl1 And Five New Susceptibility Loci

Exfoliation syndrome (XFS) is the most common known risk factor for secondary glaucoma and a major cause of blindness worldwide. Variants in two genes, LOXL1 and CACNA1A, have previously been associated with XFS. To further elucidate the genetic basis of XFS, we collected a global sample of XFS cases to refine the association at LOXL1, which previously showed inconsistent results across populations, and to identify new variants associated with XFS. We identified a rare protective allele at LOXL1 (p.Phe407, odds ratio (OR) = 25, P = 2.9 x 10(-14)) through deep resequencing of XFS cases and controls from nine countries. A genome-wide association study (GWAS) of XFS cases and controls from 24 countries followed by replication in 18 countries identified seven genome-wide significant loci (P < 5 x 10(-8)). We identified association signals at 13q12 (POMP), 11q23.3 (TMEM136), 6p21 (AGPAT1), 3p24 (RBMS3) and 5q23 (near SEMA6A). These findings provide biological insights into the pathology of XFS and highlight a potential role for naturally occurring rare LOXL1 variants in disease biology.Wo