ㄧ個用艾蒙延遲模組的時序驅動工程變更繞線器

Abstract

由於時序延遲違反(timing delay violation)問題在現代複雜的設計中時常發生，而且工程變更(ECO)可以改變一個已經存在的設計而不用重複執行許多較早的階段，近年來用工程變更解決跟時序(timing)有關的問題已經變得非常重要。這篇論文提出一個藉由修改一個已被細部繞線(detail-routed)的網路(net)來降低關鍵點(critical sink)的連線延遲(interconnection delay)的新穎且有效的時序驅動(timing-driven)工程變更繞線演算法-TDER。在繞線階段後，TDER演算法藉由 (1) 在第一階段合併適合的子樹和 (2) 在第二階段用一個有效的路徑刪除策略來微調適當的史坦那點(Steiner point)去修改一個已被細部繞線的網路。此外，這篇論文也提出一些可信賴的標準去估計當一個繞線樹(routing tree)被修改時，關鍵點的時序變化。實驗結果顯示TDER演算法可以有效地降低關鍵點的連線延遲。

Timing-related problems in ECO have become significant in recent years since timing delay violations occur frequently in current complex designs and ECO can incrementally change an existing design without repeating many early stages. This paper presents a novel and effective Timing-Driven ECO Routing algorithm (TDER) to reduce interconnection delay of the critical sink by modifying a detail-routed net. In the post-routing stage, TDER modifies a detail-routed net by (i) merging suitable subtrees in the first stage, and (ii) refining proper Steiner points with an efficient path-pruning heuristic in the second stage. Furthermore, this paper also develops several reliable criteria to estimate timing variation of the critical sink when a routing tree is modified. Experimental results show that TDER can reduce interconnection delay of the critical sink effectively.