我們提出結合 net-based 和 path-based 時序驅動佈局為了更好的權衡精準度和複雜度。
我們雇用一個力導向遞迴改善方法並且設計一個基於 Slack 的 成本函式 那能更精準的捕抓時序違例和可操作性。
我們的成本函式能調整權重在 late, early, total 和 worst slack 為了可操作性。
我評估我們的方法使用 ICCAD2014 ITDP 競賽的框架。
它設置了一個移位限制在 cell 移動用來保留全域佈局的結果。
實驗結果顯示我們的方法有效地降低合法全域佈局的時序違例。
在平均上，total negative late slack, worst negative late slack, total negative early slack 和 worst negative early slack
有分別得到 99.98%, 96.28%, 32.23% 和 34.87% 的改善。

We propose combining net-based and path-based timing-driven placement for better trade off between accuracy and complexity.
We employ a force-directed iteration improvement approach and design a slack-based cost function that accurately captures timing violation and maneuverability.
Our cost function can adjust weights on late, early, total, and worst slack for maneuverability.
We evaluate our approach using the ICCAD2014 ITDP contest framework.
It sets a displacement constraint on cell movement to preserve global placement result.
Experiment results show that our approach significantly reduces timing violation from the initial legalize global placement.
On average, total negative late slack, worst negative late slack, total negative early slack and worst negative early slack
have been improved by 99.98%, 96.28%, 32.23% and 34.87%, respectively.

Abstract - i
Acknowledgements - ii
Contents - iii
List of Figures - iv
List of Tables - v
1 Introduction - 1
2 RelatedWork - 4
3 Timing Model - 6
3.1 Interconnect Delay - 6
3.2 Combinational Element Delay - 7
3.3 Sequential Element Delay - 8
3.4 Timing Propagation - 9
4 Proposed Methodology - 12
4.1 Path-based Iteration - 12
4.2 Net-based Process - 14
4.3 Cost Function - 15
4.3.1 Slack Change due to Cell Movement - 16
4.3.2 Wire Delay Correction - 18
4.3.3 Slack-based Cost Function - 19
5 Experiment Results - 22
6 Conclusion - 27
Bibliography - 28

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