FXM Libraries

FX (fast transistor) models are a key component of Amber Path FX's SPICE accurate timing and SBOCV Table Generation. 

TSMC customers can get pre-built FXM libraries through their TSMC account manager.  

Custom library characterization is available upon request.  Characterization can usually be accomplished in a matter of hours not days like some other approaches.

The FX Model

Amber Path FX’s accuracy comes from the FX model. FX is a transistor level model whichcan be used to calculate timing and variance. The FX model is used to create transistor levelrepresentations of each of the cells in a library directly from the extracted SPICE netlists andTSMC BSIM SPICE model.

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

Amber Path FX allows path delay to be calculated using all, some or none of the TSMC BSIM variance variables. The TSMC SPICE model has Global and Local variance variables. Global variables refer to die to die variance. Local variables refer to on die variance. In addition, with additional characterization specific process points can be timed. Amber allows:

• 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

The FXM white paper has more information.