[SOLVED] GDCAP cell in TSMC library

[stevenv07]

Hello everyone,

Could you explain me what is the GDCAP cell in TSMC libbrary?

As I know it is a gate array decap cell which is a kind of ECO cell.

Thank you so much
Steve.

 

[ThisIsNotSam]

dcap usually stands for decoupling cap cell, which should help with power distribution concerns

 

[stevenv07]

I know dcap cell, but gdcap means gate array decap. Why do we need to use gdcap?

 

[oratie]

You need to have some spare cells in design. In case of ECO after (or just before Tape-out) you will be able to use these spare to fix your logic/timing/... problems. It is clear. So, why not to use these spare cells as DCAP cells? if you don't use them, they will serve as dcap. If you need them, you can replace these GDCAP with GNAND/GXOR/GMUX/GSDF/... So, if no ECO - they will work as DCAP, if any ECO - they will work as spare cells.

If you replace GDCAP with GXOR (as example), the only layers modified are M1(maybe VIA1), OD/PO will not be modified.

 

[stevenv07]

I understand it. Thank you so much.