解決工程改變中所產生之輸入扭轉違規與輸出負載違規

Abstract

為了要縮短進入市場之時間，以及減少先進製程中光罩之費用，只更改繞線之工程改變已經變成一個實際而且吸引人的技術，用來處理漸進式的設計改變。由於可供利用之緩衝器數目有限，新更改之電路常常會違反輸入扭轉限制與輸出負載限制，導致整體設計之時間收斂失敗，或是被延後。在這個計畫中，我們提出了名叫MOESS的方法，將備份的單元加入至連線中做為緩衝器，進而解決輸入扭轉違規與輸出負載違規。MOESS使用兩種插入緩衝器之機制，先將所需要使用之緩衝器降至最低，接著修正任何隨之而來的時間違規。我們所提之方法是建構在一現有之工業界後段工具之上，並可以轉移到其他之後段工具，只要此工具有提供對於其設計資料庫公開存取之介面。

To shorten the time-to-market and reduce the expensive cost of photomasks in advance process technologies, metal-only ECO has become a practical and attractive solution to handle incremental design changes. Due to limited spare cells in metal-only ECO, the new added netlist may often violate the input-slew and output-loading constraints and, in turn, delay or even fail the timing closure. In this project, we propose a framework, named MOESS, to solve the input-slew and output-loading violations by connecting spare cells onto the violated nets as buffers. MOESS provides two buffer insertion schemes performed sequentially to minimize the number of inserted buffers and then to solve timing violations if there is any. The whole framework is built based on a commercial APR tool and can be ported to any other APR tool offering open access to its design database.