Gradient-Guided RC Weighting for Timing-Driven Global Routing

As a critical step in electronic design automation (EDA), global routing provides a guide to subsequent steps and provides valuable feedback to previous steps, including congestion, timing, and power estimation. However, given the complexity of timing and power calculation, it is difficult to estimate the impact on timing and power during the routing process. To address this issue, we propose a gradient-guided framework that computes the ''capacity sensitivity'' and ''resistance sensitivity'' of each segment to estimate their influence on the timing objectives. Integrating these two values as weights to constrain the changes in capacitance and resistance of the wire segments, we develop a timing-driven global router with superior performance. Power is also considered by optimizing the cells' switching power. Tested on ISPD25 Contest benchmarks, we can achieve 14.3% and 18.5% improvements in worst negative slack and total negative slack, respectively, with comparable congestion. With power optimization, we can further improve switching power by 10.6%.