Patent ID: 8515725
Filing Date: 2013-08-20
Classification: G06F

Abstract:
1. A method of modeling a digital circuit having at least one nonlinear charge source at an input port or output port of the circuit, said method comprising: performing a simulation of the circuit by iteratively applying input ramp voltage waveforms on a circuit input port ‘A’ at a different capacitive output load (Cload) at an output port ‘B’ at each iteration, wherein at each iteration, said input ramp voltage waveform is swept at different voltage slew rates; determining, at successive time steps of each iteration, a voltage value Vi on said input port ‘A’, a voltage value Vo on the output port ‘B’, and current values (ia) and (ib) on the input port ‘A’ and output port ‘B’ respectively, at each capacitive output load; computing, from the current values (ia) and (ib), for each successive time step of each said iteration, at least one charge value for an input charge source (Qa(Vi,Vo)) at input port ‘A’ and at least one charge value for an output charge source (Qb(Vi,Vo)) at output port ‘B’ as a function of Vi and Vo voltage values, said at least one charge value for an input charge source or output charge source being computed based on a combination of Vi and Vo voltage values; and generating an input or output nonlinear charge source from the at least one charge value, said input or output nonlinear charge sources used in modeling a dynamic behavior of said digital circuit.