Simple metrics for slew rate of RC circuits based on two circuit moments

In this paper, we introduce simple metrics for the slew rate of an RC circuit based on the first two circuit moments. We develop two new slew metrics, S2M (slew with 2 moments) and scaled S2M, that provide high accuracy with the advantage of simple closed form expressions. S2M is very accurate for middle and far end nodes but it does not perform as well for near end nodes. Scaled S2M is developed to improve upon S2M for near end nodes and is shown to be highly accurate for near as well as far end nodes. For a large set of nets from an industrial 0.18 μm microprocessor, S2M matches SPICE within 2% on average with 78% of the sinks having less than 1% error. For the same test cases, the average error for scaled S2M is less than 3% with 99.4% of the nodes showing less than 5% error.