Algorithms for simultaneous consideration of multiple physical synthesis transforms for timing closure

We propose a post-placement physical synthesis algorithm that can apply multiple circuit synthesis and placement transforms on a placed circuit to improve the critical path delay under area constraints by simultaneously considering the benefits and costs of all transforms (as opposed to considering them sequentially after applying each transform). The circuit transforms we employ include, but are not limited to, incremental placement, two types of buffer insertion, cell resizing and cell replication. The problem is modeled as a min-cost network flow problem, in which nodes represent circuit transform options. By carefully determining the structure of the network graph and the cost of each arc, a set of near-optimal transform options can be obtained as those whose corresponding nodes in the network graph have the min-cost flow passing through them. We also tie the transform selection network graph to a detailed placement network graph with TD arc costs for cell movements. This enabl...

• Type: Conference
• Year: 2008
• Where: ICCAD
• Authors: Huan Ren, Shantanu Dutt
• Keywords: Circuit Transform Options, Hardware, ICCAD 2008, Near-optimal Transform Options, Transform Selection Network