2252308
Cost-Driven Hybrid Configuration Prefetching for Partial Reconfigurable Coprocessor
Reconfigurable computing systems have developed the capability of changing the configuration of the reconfigurable coprocessor multiple times during the course of a program. However, in most systems the reconfigurable coprocessor wastes computation cycles while waiting for the reconfiguration to complete. Therefore, the high demand for frequent run-time reconfiguration directly translates into higher reconfiguration overhead. Some studies have introduced the concept of prefetching to reduce the reconfiguration overhead. However, these prefetching algorithms are probability-driven. We believe that including configuration size information in the prediction algorithm directly links the training of the predictor with the performance gain. Therefore we proposed a performance-oriented cost-driven algorithm for coarse-grained configuration prefetching. Our cycle accurate simulation results show that the proposed cost-driven algorithm outperforms the probability-driven predictor by 10.8% to 29.6% in reducing reconfiguration overhead.
53249448
Efficiently generating test vectors with state pruning
10261174
Microarchitecture-aware floorplanning using a statistical design of experiments approach
Since across-chip interconnect delays can exceed a clock cycle in nanometer technologies, it has become essential in high performance designs to add flip-flops on wires with multi-cycle delays. Although such a wire pipelining strategy allows higher operating frequencies, it can reduce the delivered performance of a microarchitecture, since the extra flip-flops inserted may increase the operation latencies and stall cycles. Moreover, the addition of latencies on some wires can have a large impact on the overall performance while other wires are relatively insensitive to additional latencies. This varying sensitivity suggests the need for a throughput-aware strategy for pipelining the interconnects that interacts closely with the physical design step, which determines the lengths of these multicycle wires. We use a statistical design of experiments strategy based on a multifactorial design, which intelligently uses a limited number of simulations to rank the importance of the wires. When applied at the floorplanning level, our results show improvements both in the overall system performance and in the total wire length when compared with an existing technique.
14171562
Enhancing the Memory Performance of Embedded Systems with the Flexible Sequential and Random Access Memory
The on-chip memory performance of embedded systems directly affects the system designers’ decision about how to allocate expensive silicon area. We investigate a novel memory architecture, flexible sequential and random access memory (FSRAM), for embedded systems. To realize sequential accesses, small “links” are added to each row in the RAM array to point to the next row to be prefetched. The potential cache pollution is ameliorated by a small sequential access buffer (SAB). To evaluate the architecture-level performance of FSRAM, we run the Mediabench benchmark programs [1] on a modified version of the Simplescalar simulator [2]. Our results show that the FSRAM improves the performance of a baseline processor with a 16KB data cache up to 55%, with an average of 9%. We also designed RTL and SPICE models of the FSRAM [3], which show that the FSRAM significantly improves memory access time, while reducing power consumption, with negligible area overhead.
6494882
State pruning for test vector generation for a multiprocessor cache coherence protocol
Verification is extremely important in designing digital systems such as a cache coherence protocol. Generating traces for system verification using a model checker and then using the traces to drive the RTL logic design simulation is an efficient method for debugging. This method has been called the witness string method (Abts and Roberts, 1999), which is based on DFS. We investigate a state pruning method that exploits multiple search heuristics in simultaneous DFS searches to choose the most efficient traces. We distribute the hash table of the entire state space among the simultaneous searches so that they cooperate to avoid redundant state exploration. To evaluate this search algorithm, we implant several protocol bugs in the Stanford DASH cache coherence protocol. Using an IBM Power4 system with the Berkeley Active Message library, we show an improvement in witness strings generation through the state pruning method over a pure DFS and a guided DFS.
1935912
A Novel Memory Structure for Embedded Systems: Flexible Sequential and Random Access Memory
The on-chip memory performance of embedded systems directly affects the system designers' decision about how to allocate expensive silicon area. A novel memory architecture, flexible sequential and random access memory (FSRAM), is investigated for embedded systems. To realize sequential accesses, small “links” are added to each row in the RAM array to point to the next row to be prefetched. The potential cache pollution is ameliorated by a small sequential access buffer (SAB). To evaluate the architecture-level performance of FSRAM, we ran the Mediabench benchmark programs on a modified version of the SimpleScalar simulator. Our results show that the FSRAM improves the performance of a baseline processor with a 16KB data cache up to 55%, with an average of 9%; furthermore, the FSRAM reduces 53.1% of the data cache miss count on average due to its prefetching effect. We also designed RTL and SPICE models of the FSRAM, which show that the FSRAM significantly improves memory access time, while reducing power consumption, with negligible area overhead.
2517295
Automated Availability Management Driven by Business Policies
Policy-driven service management helps reduce IT management cost and it keeps the service management aligned with business objectives. While most of the previous research focuses on performance/resource managements, little has been researched in the area of availability management driven by business policies. This is a critically important task in enterprise IT, because a single failure in enterprise IT could cause huge business loss. It is still unclear how we can automate the availability management in a highly dynamic and complex system according to business level objectives for performance and risk attitude/preference. As a consequence, users can not manage the availability/performance ratio to match their risk tolerance. In this paper, we propose a policy-driven approach to automate run-time availability management in IT systems, according to high level availability and performance objectives. We further apply von Neumann-Morgenstern utility theory to deal with users' risk attitude policies, an important class of business policies specific for availability management, and the associated preference structures. Based on the proposed approach, we implement an automated decision engine for availability management. The initial evaluation of the solution illustrates the significance of the policy-driven approach and it demonstrates its applicability for availability management in complex IT environments. This way IT users can customize their availability to the risks tolerable by business objectives.
7335648
A Systolic Algorithm for the k-Nearest Neighbors Problem
The authors present a systolic algorithm and its variations for the k-nearest neighbors problem (kNNP). Multiple-shot queries with different ranges (k values) can be served in a pipelined fashion. A partitioning scheme is developed to handle large size problems. Performance of the algorithm is analyzed. Formulas for the optimal array size in terms of computation time and area-time-time product (ATT) are derived. The algorithm can solve a multiple-shot kNNP in N+2 square root N*K systolic steps using square root N*K processing elements, where N is the problem size (i.e. the number of points), and K is the sum of all k-values. >
10107398
Yet Another Induction Algorithm
Inducing general functions from specific training examples is a central problem in the machine learning. Using sets of If-then rules is the most expressive and readable manner. To find If-then rules, many induction algorithms such as ID3, AQ, CN2 and their variants, were proposed. Sequential covering is the kernel technique of them. To avoid testing all possible selectors, Entropy gain is used to select the best attribute in ID3. Constraint of the size of star was introduced in AQ and beam search was adopted in CN2. These methods speed up their induction algorithms but many good selectors are filtered out. In this work, we introduce a new induction algorithm that is based on enumeration of all possible selectors. Contrary to the previous works, we use pruning power to reduce irrelative selectors. But we can guarantee that no good selectors are filtered out. Comparing with other techniques, the experiment results demonstrate that the rules produced by our induction algorithm have high consistency and simplicity.
212430
Toward an Understanding of the Behavioral Intention to Use a Groupware Application
Groupware technologies have become an important part of the business computing and communicating infrastructure in many organizations. However, literature suggests that many groupware applications, especially those requiring significant collaboration and cooperation among users, are still not adequately used (Nunamaker, 1997; Orlikowski, 1993). Their potential benefits are far from being fully realized due to the lack of user acceptance. While there are studies that show the relevance and positive impact of group support systems on group work, very few have looked into users’ perception of the groupware technologies and their motivation to participate (Nunamaker, 1997). Expectancy theory is considered one of the most promising models of individual motivation. This study examines the use of expectancy theory in explaining the behavioral intention (motivation) to use a groupware application. Data gathered from 86 student users in a judgment modeling exercise suggest that the model is a significant predictor of users’ m tivation. The successful use of expectancy theory also suggests that it is appropriate for assessing and understanding users’ motivation to use a groupware application and, subsequently, its acceptance and success. Since user acceptance is an essential antecedent of a successful groupware application, the results of this study should be considered thoughtfully when a groupware application is designed, implemented, and operated.
8884051
Constant Time Sorting on Reconfigurable Meshes
We present a constant time sorting algorithm by adopting a 3D reconfigurable mesh with only O(n/sup 3/2/) processors. Our algorithm is developed on an n/sup 1/2//spl times/n/sup 1/2//spl times/n/sup 1/2/ 3-D reconfigurable mesh. Moreover, we further extend the result to k-dimensional reconfigurable meshes for k/spl ges/3. Consequently, an O(4/sup k+1/) time sorting algorithm is obtained by adopting an n/sup 1/(k-1)//spl times/n/sup 1/(k-1)//spl times/.../spl times/n/sup 1/(k-1)/k-D reconfigurable mesh of size O(n/sup 1+1/(k-1)/). Hence, constant time sorting using O(n/sup 1+/spl epsiv//) processors, where O >