In this paper, we propose a post-layout waveform prediction method by System Identification (SI) based on the fact that the waveforms of pre-layout and post-layout are always correlated. Mathematical models are built to describe the relationships between the pre-layout and post-layout simulation results via SI techniques. The model parameters are calibrated by using the simulation results of the first few data points of pre-layout and post-layout stages. By taking the corresponding pre-layout simulation results as inputs of the calibrated models, the rest post-layout waveforms can thus be predicted as the output of the models. Several examples demonstrate the efficiency of the prediction, which helps the designers have a quick view of the post-layout waveforms in the design process.

Simulation of power girds has become increasingly computationally expensive. In this paper, we propose a Model Order Reduction (MOR) method for power grid circuits by extending the existing Aggregation-based MOR (AMOR) method. In the proposed method, besides resistors and capacitors, current sources are also aggregated to improve MOR efficiency. Moreover, pre-partition and parallelization techniques are employed to decrease the reduction time. Numerical results demonstrate that the reduced-order models can achieve up to 18× simulation speed-up over the original circuits without much loss of accuracy.

In this paper, we propose an efficient oscillation-diminishing cubic Hermite spline interpolation method for the table-based transistor model approximation. We use the cubic Hermite spline interpolation to ensure the continuity of the derivatives. Oscillation-diminishing techniques are proposed to reduce the oscillations (bumps) of interpolations such that both convergence and accuracy are significantly improved. Further, the oscillation-diminishing schemes do not rely on any real derivatives. Therefore, the proposed method can be used to build table models from measured data of the physical devices, where the real derivatives are not always available. In the proposed method, an adaptive approach is employed to generate the nonuniform interpolation grids such that the interpolation accuracy is guaranteed and the memory requirement is minimized. We also propose a novel combined exponential extrapolation method for off-state (leakage) current, which exactly follows the exponential-decay characteristic of that current. Test simulations on several classic industrial analog and mixed-signal circuits show that the proposed method can achieve high accuracy with lower computational cost compared with existing table-based model approximation methods.