DRACULA and Calibre have huge different at Extract?

Dear All:
After extract layout, the capacitance is too large to
believe. When I used DRACULA LPE to extract layout, there are only about 6~8
capacitors extraced(0.xxxE-14~E-15), but Calibre PEX got about 24~28
capacitors, and their capacitance value is too large to believe( from 0.xxxx
~ 800.xxx), is Calibre PEX reulst correct??

or there are some unit I have to add by myself?

I am using TSMC25RF 1P5M process model.

Thanks!

Boki.

 

Both Dracula and xCalibre flows have syntax for setting
capacitance user units; you'll have to read the rule files
and TFM to find out what yours is doing.

As to the capacitor count, most likely xCalibre is extracting
coupling caps that Dracula is not.

In any case, when you start using a new capacitance tool, you
should run it on some test layout with wires you can hand-calculate,
to confirm you understand how it is working.

-Jay-