現今多核心系統內的應用程式需要存取多顆核心與外部裝置，因此在系統內常配備有匯流排裝置及直接存取記憶體控制器去管理傳輸任務。然而，由於工作具有優先順序的限制以及傳輸衝突的情況，如何針對匯流排與直接存取記憶體控制器進行適當的優先權配置是極具挑戰的問題。本研究提出兩項優先權配置演算法分別可用於靜態仲裁器與動態仲裁器，並提出工作分配演算法去降低傳輸的工作量，還提出一個可排程性測試演算法用以測試具有先後順序限制的工作在系統中的可排程性。本研究的效能分析結果顯示提出的演算法能有效提高系統匯流排使用率與可排程性。

In current multi-core systems, an application is executed in several cores and requires peripheral devices. A system bus arbiter and a direct access memory controller are used for communication management. Because of the precedence constraint between functions and the communication contention between cores, how to find a proper priority assignment for cores and devices becomes challenging. In this work, we propose two priority assignment strategies for fixed-priority and dynamic priority arbiters, respectively. A partition algorithm and a schedulability test are also presented to deal with communication overhead minimization and precedence constraint scheduling. The experimental results
show encouraging results in priority assignment.

1 Introduction 1
2 System Model 3
3 Algorithm 6
3.1 Subtask Assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.2 Priority Assignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.2.1 Workload-based . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.2.2 Bandwidth-based . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.3 Schedulability test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
3.4 Simulated Annealing Algorithm . . . . . . . . . . . . . . . . . . . . . . 16
4 Experiment 18
4.1 Data Sets and Performance Metrics . . . . . . . . . . . . . . . . . . . . . 18
4.2 Experimental Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.2.1 Varied system setting . . . . . . . . . . . . . . . . . . . . . . . . 19
4.2.2 Varied workload . . . . . . . . . . . . . . . . . . . . . . . . . . 25
4.2.3 Optimality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
5 Conclusion 31
REFERENCES 32

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