Calibre PEX can find my port but Calibre LVS could not recognise one of them

[mamadmn]

Calibre PEX can find all ports but Calibre LVS can not recognise one of them

Hi,
I can run Calibre PEX and see the result that shows 4 pins. But when I run Calibre LVS I see only 3 pins!!!! :sad:
The input pin could not be detected by LVS.

Is there any configuration I should do??
Thank you

 

[slizak]

Re: Calibre PEX can find all ports but Calibre LVS can not recognise one of them

Is the fourth pin connected to anything? I believe that by default LVS discards "trivial" pins. (Trivial pins are pins that are not part of an electrical path.) PEX doesn't, as all metal pieces (even fill) are significant for calculating capacitance.

 

[mamadmn]

Hi,
I found that in 90nm technology, I could not use Poly pin..... Although, I think it should not be true!!,,,, I used a Metal pin and everything is fine..maybe something like trivial pin you suggested...
Could you please let me know if it's true?
Thank you

 

[slizak]

How pins are defined would depend on your device definitions; Calibre LVS uses the DEVICE statement in the SVRF rule file to determine what a shape on the poly or M1 layer is doing, electrically.

If the rules you have for 90nm technology restrict pins (or ports) to M1 instead of Poly layers, there is probably a reason for it. Without knowing anything about the PDK, your layout, or the rules you are running it is impossible to say whether LVS regards the pin as "trivial". Is there a colleague you can show the problem to and get feedback? The answer really is design dependent.