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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.compeleceng.2008.11.024 Byline: Yitzhak Birk, Evgeny Fiksman Keywords: FPGA; Reconfigurable computing; Multi-context architectures Abstract: Field-programmable gate arrays (FPGAs) are being integrated with processors on the same motherboard or even chip in order to achieve flexible high-performance computing, and this may become main stream in chip multi-core architectures. However, the expensive FPGA area is often used inefficiently, with much of the logic idle at any given time. This work, motivated by the Dynamic-Link Library (DLL) concept in software, explores the possibility of 'hardware DLLs' by finding ways for fast dynamic incremental reconfiguration of FPGAs. So doing would, among other things, enable same-function replication at any given time, with functions changing quickly over time, thereby enabling efficient exploitation of data parallelism at no additional hardware cost. We present two new multi-context FPGA architectures based on two different configuration storage architectures: local and centralized. Problems such as configuration storage and reconfiguration (time, power and space) overhead are considered. Well known area and power models are used in evaluating various approaches and in order to provide guidelines for matching architectures to target applications. Lastly, we provide insights into resulting scheduling issues. Our findings provide the foundation and 'rules of the game' for subsequent development of reconfiguration schedulers and execution environments. Author Affiliation: Electrical Engineering Department, Technion-Israel Institute of Technology, Haifa 32000, Israel

The Informed-Source Coding On Demand (ISCOD) approach for efficiently supplying nonidentical data from a central server to multiple caching clients over a broadcast channel is presented. The key idea underlying ISCOD is the joint exploitation of the data blocks already cached by each client, the server's full knowledge of client-cache contents and client requests, and the fact that each client only needs to be able to derive the blocks requested by it rather than all the blocks ever transmitted or even the union of the blocks requested by the different clients. We present twophase ISCOD algorithms: the server first creates ad-hoc error-correction sets based on its knowledge of client states; next, it uses erasure-correction codes to construct the data for transmission. Each client uses its cached data and the received supplemental data to derive its requested blocks. The result is up to a several-fold reduction in the amount of transmitted supplemental data. Also, we define k-partial cliques in a directed graph and cast ISCOD in terms of partial-clique covers. Index Terms--Caching clients, clique cover, communication complexity, error-correcting codes, information dissemination, Informed-Source Coding On Demand (ISCOD), k-partial clique, maximum matching, multicast.

The Infiniband (IB) System Area Network (SAN) is assessed using a sequential-consistency Distributed Shared Memory (DSM) system. Primitives are developed that abstract the low-level communication and kernel details, and efficiently serve the application's communication, memory, and scheduling needs.

The problem of converting incoming complex datastreams into pagemaps using a page-parallel rasterizer equipped with shared memory multiprocessing elements is investigated. The problem concerns the on-line regulation of the rasterizer for preventing deadlock during out-of-order rasterization. A solution to address an implementation problem of other deadlock-avoidance methods resulting from a shared resources allocation scheme is also presented.

A shared directional multichannel (SDM) consists of a set of inputs and a set of outputs to which we connect transmitters and receivers, respectively. A signal placed at any given input reaches a subset of the outputs, and a channel is specified by the sets of outputs that are reachable from each input. A message is received successfully at an output of the channel if and only if it is addressed to the receiver connected to that output and no other signals reach that output at the same time. Constructive lower bounds as well as some upper bounds on the uniform-traffic capacity of SDM-based single-hop interconnections between a set of multitransmitter source stations and a set of multireceiver destination stations are derived. (Every source station is connected to every destination station through the channel.) A bidirectional interconnection among a set of stations would be obtained by representing each station as one source station and one destination station. Both randomized transmissions and deterministic scheduling are considered. It is shown that with randomized transmissions, SDM's that can be described as a collection of buses can perform as well as any other ones. With deterministic scheduling, however, the use of certain non-bus-oriented SDM's yields a much higher interconnection capacity.