The FX Model

The FX Model

The FX model is a fast transistor level representation of each of the cells in your design library. It is derived directly from foundry BSIM SPICE models and extracted SPICE netlists.

The FX model has substantial advantages over traditional arc models such as NLDM, ECSM and CCS. Arc based models simply miss many of the critical delay and variance effects. FX, by using a transistor model in a netlist to model each cell, has all the same advantages of a true SPICE representation.

• Full waveform propagation through all stages of path for correct slew, delay & variance
• Single model for delay, variance, noise and power
• Ability to handle multiple-input switching, noise on delay, glitch
• Ability to handle local voltage & temperature
• Proper modeling of Miller capacitances, resistive networks, nonlinear effects
• Proper modeling of long statistical tails and the full active device range
• Proper propagation of complex waveforms

The FX Model allows for:

• Nominal only processing for SPICE accurate nominal delay
• Statistical timing with global and local variables
• Statistical timing with local only variables around a fixed process corner

FX Model Generation

FX model generation is fast and can usually be accomplished in a matter of hours using a few SPICE licenses.

Selected FX models are available from TSMC. In addition, custom FX model generation is available upon request.