Hi,
I'm working on characterizing io cells. I thought of measuring Vih,Vil,Voh,Vol. I'm confused with which method to follow. In some papers its said, negative unity slope method gives pessimistic results. The better method would be Maximum square method of measuring SNM. For io cells, had anyone done any analysis of this kind. I'm intersted in sample spice decks for measuring SNM using MSM.
Also, in -ve unity slope method, does anyone know any in-built hspice commands for measuring -ve slopes/directly Vih/Vil. As I need to run for around 375 corners, I need some automated way of measuring these parameters.
Also, I could measure Hysterisis in Schmit trigger inputs, but any automated way/measure commands for measuring Vih,Vil,Voh,Vol is there?.
P.S:  The io cells are not single inverters, they are composed of more transistors.
Any help is appreciated.
Regards
Prakash