I have used the nmos2v_mis model and section 'tt' in cadence spectre for performing dc mismatch simulation of a simple current mirror , however i am getting  0 % variance for all parameters.how do i include the dc mismatch parameters to get the correct results.

Dear Marq and Rad,

dcmismatch simulation parameters have nothing to do with the mismatch data meant for MC statistical analysis. These are 2 things different altogether. There is a thread in the Cadence's sourcelink where the difference between DCmismatch and MC statistical mismatch is detailed. Can't remember the SR number off the to of my head. A little search would spot it out.

The dcmismatch data is often available within the TYP corners.
For BSIM3V3 MOSFETS, Spectre does support the following parameters for dcmismatch : (spectre -h bsim3v3)

;
DC-mismatch dependent parameters:
279     mvtwl=0.0 v*m     Threshold mismatch area dependence.
280     mvtwl2=0.0 v*m^1.5 Threshold mismatch area square dependence.
281     mvt0=0.0 V        Threshold mismatch intercept.
282     mbewl=0.0 m       Beta mismatch area dependence.
283     mbe0=0.0          Beta mismatch intercept.
284     mismatchmod=0     select Mismatch mode.
285     mismatchdist=0 m  Mismatch Distance.
;

One can then grep one of the above parameters in the model file to check whether the data is there or not.

There are ways of extracting these parameters otherwise, a bit tricky but still possible in some cases ...

Cheers  ;)
Riad.