Power Grid Correction Using Sensitivity Analysis Under An RC Model

Verifying the power grid requires checking if the voltage drops on all the nodes do not exceed the threshold. We aim to correct an RC model of the grid when some voltage drops violate the threshold condition, by making minor changes to the original design. We first propose an accurate approach to correct the grid which turns out to be too slow. We therefore propose another approach, more suitable for large grids and which can be summarized as follows. The voltage drop is estimated as a function of the metal widths on the grid. A non-linear optimization problem is then formulated and the required metal line width changes that reduce the voltage drops by a sufficient amount are determined. There is a tradeoff between accuracy and speed of the algorithm. However the results show that the gain in speed achieved by the second method, outweighs greatly the loss in accuracy.MAS