隨著多核心系統成為當今設計的主流，設計者須要相對應的多核心指令集模擬器來幫助系統開發。多核心模擬器可由數個獨立的單核心模擬組成。理想上，我們可以將多核心模擬平行化運作以加快模擬速度。但傳統集中式的時間同步方法會大幅限制其平行度，讓速度難以提升。為解決此一問題，本研究提出一種新的分散式同步方法，藉此增加多核心模擬的平行程度，進而提升整體的模擬速度。利用分散式的排班法，讓每一個模擬器各自獨立運作，使得同一時間內可以有更多的模擬器一起執行。此外，我們的方法更預測未來同步點可能的發生時間，並根據預測的結果來有效地縮減每次同步所花費的等待時間。因此可達到更高的平行度，進而提升整體多核心模擬的效能。根據我們的實驗結果，在同樣共享記憶體的同步方式下，我們所提出的分散式技術隨著模擬核心的增加，相較於傳統集中式排班法可以提升至九到二十倍的模擬效能。

As multi-core architecture has become the mainstream, the corresponding multi-core instruction-set simulation (MCISS) is also needed to aid system development. Ideally, we may run a MCISS in parallel to enhance the simulation speed. However, the conventional centralized timing synchronization mechanism would greatly constrain the parallelism of a MCISS so that the simulation speed is bounded. To resolve this issue, we propose a new distributed timing synchroni-zation technique which allows higher parallelism for a high-speed MCISS. By allowing each ISS to schedule with others independently, more ISSs can run in parallel. Furthermore, the proposed distributed technique predicts the possible time of each ISS’s future sync point (i.e., the time point for synchronization). Based on this prediction, the time spent on synchronization is effectively reduced, thereby leading to higher parallelism for better simulation performance of a MCISS. The experimental results show that for the same shared memory based synchronization, our distributed technique improve the simulation performance by 9 to 20 times over the conventional centralized approach as the number of cores increases.

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