ECO for setup violations

[supersonic_528]

If I have setup violations in my netlist and fixing them in PrimeTime, what kind of ECO is recommended and why?

(1) Upsizing the cells
(2) changing cell type from HVT to SVT/LVT (or from SVT to LVT)

I was going with #1 but then someone told me #2 is better since it has less side effect on crosstalk.

Thanks.

 

[maxscipio]

Hi supersonic_528,

the advantage of 2 is that you can do an analysis in PT (swapping the cell) that is very close to the post ECO situation since you aren't going to touch the routing anymore.

cheers

 

[supersonic_528]

Thanks for your reply. Why will option #2 be more close to post ECO situation than option #1 ?

 

[maxscipio]

Because you don't change the routing at all since the 2 cells (HVT and other VT) have the same physical size / pins location.

 

[jeevan.life]

But considering changing the VT of the cells give a thought on the leakage aspect as well...LVT has more leakage..may affect your design..If you have routing space I would recommend #1 for you.



Helpful?

 

[michealwolf]

The physical changes of #2 is only change the cells. No wires will be changed. So, no extra iteration between STA and PR will be required.
BTW, make sure use LVT will not introduce extra layers to your chip.