123088
A phase assignment method for virtual-wire-based hardware emulation
In a hardware emulator consisting of multiple field-programmable gate arrays (FPGAs), the utilization of the FPGA logic resource is usually very low due to the limitation on the number of I/O pins. Virtual wire technology not only increases the inter-FPGA communication capability, but it also increases the logic resource utilization by means of time division multiplexing (TDM). TDM allows one physical wire to be shared by multiple logical wires. For TDM to be effective, each transportation of an inter-FPGA signal must be carefully assigned to a slot of the time division. In this note, we show that the phase assignment problem is exactly same as the resource-constrained operation scheduling problem. We adopt the static-list scheduling heuristic for the task, and present some experimental results on a set of benchmark circuits from the MCNC. The experiments show that the proposed method can increase the number of effective I/O pins as many as ten times.
195838317
Data path allocation based on bipartite weighted matching
Proposes a graph-theoretic approach for the data path allocation problem. The problem is decomposed into three subproblems: (1) register allocation, (2) operation assignment, and (3) connection allocation. The first two subproblems are modeled as two bipartite weighted matching problems and solved using the Hungarian method. The third subproblem is solved using a greedy method. It is shown that, by taking the other into consideration while solving one, equally satisfactory results can be obtained, regardless of the order in which (1) and (2) are performed. Two programs, LYRA and ARYL, are implemented which solve the subtasks in different orders. For register allocation, the approach is the first one to guarantee minimal use of registers while being able to take the interconnection cost into account. This research has demonstrated that the bipartite weighted matching algorithm is indeed a good solution for the data path allocation problem.<<ETX>>
53235373
Performance-optimal clustering with retiming for sequential circuits
195837942
Optimum and heuristic data path scheduling under resource constraints
An integer linear programming model for the scheduling problem in high-level synthesis under resource constraints is presented. The following applications are considered: multicycle operations with nonpipelined or pipelined function units: mutually exclusive operations: functional pipelining: loop-folding; and scheduling under bus constraint. Besides the model, a new technique, called zone scheduling (ZS), is proposed to solve large-size problems. ZS partitions the distribution graph into several zones and sequentially solves the problems contained. A novel feature of this technique is that it schedules more than one control step at a time, allowing a more global view of a scheduling problem to be taken.<<ETX>>
6763648
An effective methodology for functional pipelining
We address the problem of given a loop behavior, a target initiation interval and resource constraints, scheduling a loop in a pipelined fashion such that the iteration time (turn-around time) is minimized. The iteration time is an important quality measure of a data path design because of its direct correlationship with both the storage and the control costs. Our scheduler starts with performing an As Soon As Possible Pipelined (ASAPp) scheduling without regard to the resource constraint. It then resolves the resource constraint violations, if there are any, by repeatedly rescheduling some operations.
16396963
Performance-driven interconnection optimization for microarchitecture synthesis
This paper addresses the interconnection synthesis problem in microarchitecture-level designs. With emphasis on the speed of data movement operations, we propose algorithms that take into consideration the effect of each data-transfer-to-bus binding on the data transfer delay time. The delay time is calculated as a function of both data source load and data carrier (bus) load. By balancing loads among hardware components, the data transfer delay time (hence the total execution time) is shortened. We consider two types of problems: resource-constrained binding and performance-constrained binding. Two integer linear programming (ILP) formulations are derived to optimally solve the problems. In order to speed up the computation, a bipartite weighted matching method for the resource-constrained binding and a greedy merging method for the performance-constrained binding are also proposed. Both the ILP formulation generators and the heuristics have been programmed. Experimental results indicate that the proposed algorithms are indeed very effective in optimizing the performance aspect of the interconnection design. >
28041902
Guest Editorial: Special Section on Wireless Internet
WIRELESS communications have made spectacular progress in recent years. In particular, the merge of various wireless communication systems and the Internet has become more critical so that users can enjoy all kinds of services in the Internet while owning mobility. For example, modern wireless networks can support Internet applications for web accessing and multimedia services. Many issues need to be addressed for such combinations. Host mobility adds a new dimension to many research issues, such as network protocols, resource managements, Web access, and multimedia transmission. For different applications, diverse traffic types should be supported. Lightweight mobile computing devices, such as PDAs and Bluetooth, will be attached to the Internet. Various wireless communication devices, such as Bluetooth and wireless LANs, will be hooked up to the Internet. All these issues bring new challenges. This special section is targeted at the related issues in wireless Internet. More than 50 submissions were received, and 10 papers were accepted in this special issue. The first five papers cover the service issues in wireless Internet. The paper by B. Emako, R. Glitho, and S. Pierre discusses the design, implementation, and evaluation issues of wireless Internet telephony. Y. Lee and I.F. Akyildiz present a new scheme to reduce the link and signaling costs in Mobile IP. The paper by P. McKinley, U.I. Padmanabhan, N. Ancha, and S.M. Sadjadi describes a composable proxy infrastructure that enables mobile Internet users to collaborate via heterogeneous devices and network connections. V.A. Chitre and J.N. Daigle present an analytical model to assess GPRS’s capability of supporting IP-based Internet services. Performance optimization of VoIP calls over wireless links using H.323 protocol is proposed by S.K. Das, E. Lee, K. Basu, and S.K. Sen. Thenextsetof threepaperscovers issuesrelatedtowireless LANs and sensor networks. The important coverage issue concerning the deployment of sensors in a wireless ad hoc sensor network is addressed in the first paper by X.-Y. Li, P.-J. Wan, and O. Frieder. A polling mechanism to support QoS in IEEE 802.11 wireless LANs is proposed by S.-C. Lo, G. Lee, and W.-T. Chen. Formation of scatternets for Bluetooth-based wireless networks is discussed in the paper by C. Petrioli, S. Basagni, and I. Chlamtac. The last set of two papers covers management issues in mobile networks. An analysis for movement-based mobility management in mobile networks is discussed in the first paper by Y. Fang, who makes a thorough numerical analysis for finding the optimal mobility management under various network operation scenarios possible. Admission control for schedulingbursty traffic inCDMAsystems isdiscussed in the paper by Y.-K. Kwok and V.K.N. Lau, where six efficient rate allocation schemes are proposed. Finally, wewould like to take the opportunity to thank the contributingauthors, reviewers, theAreaEditor,Dr. S.L.Min, and the Editor-in-Chief, Professor J.-L. Gaudiot. Without their support, this special section would not be possible.
26216894
Equal resource sharing scheduling for PCS data services
For high speed mobile communication applications, the data rate can be increased by using multiple channels (or time slots) instead of one channel. To reduce the high blocking rate of multiple channels assignment, flexible resource allocation strategies have been proposed. This paper proposes the Equal Resource Sharing Allocation scheme (ERSA scheme) for flexible resource allocation. The ERSA scheme dynamically averages the allocated resource to the call requests based on the number of calls in a base station. The scheme accommodates the maximum number of requests while providing acceptable quality to the admitted requests. We developed an analytic model to investigate the performance of ERSA, and conducted simulation experiments to validate the analytic model. We define satisfaction indication SI as the performance measurement of the resource allocation algorithm. The experiment results indicate that the ERSA scheme outperforms other resource allocation algorithms proposed in our previous study.
27686957
Determining the Global Progress of Parallel Simulation
10171431
Parallel Trace-Driven Simulation of Packet-Switched Multiplexer Under Priority Scheduling Policy
Abstract We proposed an approximate parallel simulation for packet loss of packet-switched multiplexer with priority scheduling policy. The speedup of the algorithm over the sequential simulation is O(N), where N is the number of processors. For packets with priority level m, the number Lm of lost packets computed in the algorithm is bounded by the exact number LmE within 2(N−1) packets. That is, |Lm−LmE| ⩽2(N−1).
3227227
Dynamic Resource Assignment Strategies for PCS Data Services
For high speed mobile communication applications, the data rate can be increased by using multiple channels (or time slots) instead of a single channel (or time slot). To reduce the high blocking rate of multiple channels assignment, flexible resource allocation strategies are exercised. This paper proposes a generic Mobile Switching Center (MSC) resource allocation algorithm called MRA algorithm for Personal Communications Services (PCS) data services. The algorithm may combine with any base station resource allocation algorithms proposed in our previous study. A simulation model is proposed to investigate the performance of these algorithms. We define satisfaction indication SI to measure the performance of the resource allocation. SI indicates the customer's satisfaction about the call connection, it can also be used by the service provider as a charge indication.