Why no filler cells in netlist when doing LVS ?

[owen_li]

Hi.

When we are doing LVS in my current chip, we just write out the normal standard cells and decap cells into the final netlist, but ignore the filler cells.

However, LVS passed. I wonder why the filler cells are not dump into netlist ?

But the fillers are actually included in the GDSII file.

Thanks all!

 

[oratie]

The filler cells do not contain any devices - just M1 power rails and NWELL. So, nothing to compare during LVS.

 

[Somashekhar]

owen_li
Fillers are added in the design to keep power rail and NWELL continuity. Also if design changes after BASE PG, then these FILLER can be replaced with ECO cells.

As oratie said, there is nothing to compare in FILLER. So NETLIST does not contain FILLER, but GDSII is the final deliverable and used for PG. Hence GDSII should contain FILLER info.

 

[owen_li]

got it, thanks all!