Automated Extraction of Accurate Delay/Timing Macromodels of Digital Gates and Latches using Trajectory Piecewise Methods

We present a fundamentally new approach, ADME, for extracting highly accurate delay models of a wide variety of digital gates. The technique is based on trajectory-piecewise automated nonlinear macromodelling methods adapted from the mixed-signal/RF domain. Advantages over prior current-source models include rapid automated extraction from SPICE-level netlists, transparent retargetability to different design styles and technologies, and the ability to correctly and holistically account for complex input waveform shapes, nonlinear and linear loading, multiple input switching, effects of internal state, multiple I/Os, supply droop and substrate interference. We validate ADME on a variety of digital gates, including multi-input NAND, NOR, XOR gates, a full adder, a multilevel cascade of gates and a sequential latch. Our results confirm excellent model accuracy at the detailed waveform level and testify to the promise of ADME for sustainable gate delay modelling at nanoscale technologies.