ITOP: integrating timing optimization within placement

Timing-driven placement is a critical step in nanometerscale physical synthesis. To improve design timing on a global scale, net-weight based global timing-driven placement is a commonly used technique. This paper shows that such an approach can improve timing, but often degrades wire length and routability. Another problem with existing timing-driven placers is inconsistencies in the definition of timing closure. Approaches using linear programming are forced to make assumptions about the timing models that simplify the problem. To truly do timing-driven placement, the placer must be able to make queries to a real timing analyzer with incremental capabilities. This paper describes an incremental timing-driven placer called ITOP. Using accurate timing from an industrial static timer, ITOP integrates incremental timing closure optimizations like buffering and repowering within placement to improve design timing without degrading wire length and routability. Experimental results on a ...

• Type: Conference
• Year: 2010
• Where: ISPD
• Authors: Natarajan Viswanathan, Gi-Joon Nam, Jarrod A. Roy, Zhuo Li, Charles J. Alpert, Shyam Ramji, Chris Chu
• Keywords: Design Timing, Hardware, ISPD 2010, Timing Closure, Timing-driven Placement