What should we learn from... Reconfigurable Systems

The special issue of Proceedings of the IEEE in April is the first of two special issues providing an in-depth treatment of the subject of reconfigurable systems as enabled through advancements in the electrical engineering field, as well as the approaches we use to manage complexity in systems having millions of fixed and programmable elements. It is the editors’ view that the frenetic evolution of the field programmable gate array (FPGA) as a preeminent digital platform will not only continue for the foreseeable future, but will serve as an inspiration/template for other functional domains to include analog, radio-frequency, photonic, and even those not strictly electrical in nature to include thermal, fluidic, and mechanical. This issue will serve as an immersion into the subject of reconfigurable systems, both for the purposes of gaining familiarity with essential theoretical elements, the key developments in the field, and the potential future directions (not just the next few years, but decades beyond the present).

The two dedicated special issues of the Proceedings of the IEEE explore the fundamental concepts behind reconfigurable systems, from the earliest foundations of computation to architectures of modern FPGAs. The three themes that will be addressed in the first special issue on reconfigurable systems include digital reconfigurability, tools for reconfigurable systems, and configurable radio technologies.

The first paper of this special issue, ‘‘Introduction to Reconfigurable Systems,’’ developed by the guest editorial team, will attempt to provide a broad overarching framework for what we believe to be an emerging discipline of reconfigurable systems. They discuss some of the key defining qualities of reconfigurable systems and examine two broad facets: designing for reconfigurability and designing with reconfigurability.

The next four papers focus on field programmable gate array and reconfigurable computation. In ‘‘Three Ages of FPGAs’’, Xilinx’s Steve Trimberger reflects on how technology evolution has driven the design of FPGAs reconfigurable digital technology through three epochs: the age of invention, the age of expansion, and the age of accumulation, showing how reconfigurability moved from an ‘‘overhead’’ cost to an economic advantage as costs and demands shifted with technology. The history of the FPGA is a fascinating story, but the future will be even more exciting. The next two papers, ‘‘Reconfigurable Computing Architectures’’ and ‘‘Fundamental Underpinnings of Reconfigurable Computing Architectures,’’ consider how reconfigurable digital technologies have blurred boundaries of hardware and software. And in ‘‘High-Reliability FPGA-Based Systems: Space, High-Energy Physics, and Beyond,’’ Wirthlin highlights some of the challenges in creating reliable reconfigurable systems.

The role of tools for managing reconfigurability will be as important as the technology itself. In ‘‘High-Level Language Tools for Reconfigurable Computing,’’ Windh et al. provide a focused survey of five tools (Xilinx Vivaldo, Altera OpenCL, Bluespec System Verilog, UC Riverside’s Optimizing Compiler for Configurable Computing, and University of Toronto’s LegUp) for enhanced productivity code development for FPGAs.

While software radio can be viewed as a ‘‘killer application’’ for reconfigurability, the challenges of harnessing the full potential of software radio will be daunting. Four papers will address the relation between reconfigurable systems technologies and radio applications. In ‘‘Software-Defined Radio: Bridging the Analog-Digital Divide,’’ Machado and Wyglinski describe the evolution of software radio. The next two papers span reconfigurability from the RF front end through the signal chain. Costantine et al., in the paper ‘‘Reconfigurable Antennas: Design and Applications,’’ discuss design, manufacture, and control concepts for antennas that employ programmable features. Rais-Zadeh et al. examine potential technologies in their paper (‘‘Reconfigurable Radios: A Possible Solution to Reduce Entry Costs in Wireless Phones’’) that could be used to implement fully reconfigurable radios and also evaluate the ability of such radios to reduce spectrum acquisition entry costs for new competitors in wireless service. In radio domain, a paper by Reed et al., titled “Software Frameworks for SDR.’’  discusses how recent advances in software frameworks (in particular, REDHAWK) allow for more reconfigurability and gluing together of reconfigurable components to make a system.

In the second special issue (later this year), other important applications of reconfigurability in another potential ‘‘killer app’’ domain: software-definable networking (wired and wireless) will be examined which will illuminate other extensions in the performance of digital reconfigurability and focus on more advanced concepts, namely those pertaining to analog systems, photonics, metamaterials, with some commentary on the possibilities of programmable matter.

Reference

James Lyke, Cristos G. Chiristodoulou, Alonzo Vera, Art H. Edwards. Special Issue on Reconfigurable Systems: Foundations. Proceedings of the IEEE, April 2015. 287-290