Brian Hargrove Leonard

Online placement infrastructure to support run-time reconfiguration

The requirements for placing modules in an automatic run-time reconfigurable (RTR) system differ from those of ASIC and other static environments. The most notable difference is the continual addition and removal of modules from the FPGAs. We examine the effectiveness of a collection of two-dimensional placement decision algorithms in a RTR environment. New algorithms are proposed in addition to several which have been adapted from their one-dimensional counterparts. All of the algorithms have been tested on a set of benchmark applications. Six programs used for testing include examples from encryption, image processing and matrix manipulations, as well as arithemetic, assignment, and looping benchmarks. These applications are multiplexed and simulated to run on our RTR system. A simple last-accessed removal scheme with no compaction is currently implemented. The merit of each algorithm is determined by a set of factors that include fragmentation, chip utilization, decision time, and program run-time benefit.

Online architectures: A theoretical formulation and experimental prototype☆

Abstract This article describes a class of reconfigurable computing system called online architectures. These architectures use an online algorithm to make run-time reconfiguration decisions that continually adapt the underlying architecture to match the application’s current computational demand. Online architectures have several potential advantages, including better resource utilization (reduced cost), faster execution, and reduced (static) power consumption. However, to realize these benefits, online architectures must balance the overhead (reconfiguration, profiling, and decision costs) against expected gains of reconfiguration. In this article, the basic foundation of online architecture is formulated, core challenges enumerated, and results reported based on a simple prototype and trace-driven simulations. These results suggest that the overhead is manageable and that a more comprehensive investigation is worthwhile.