Krzysztof Herman

11/17/2021, 2:11 AM
Hi, I have a question about the timing. How do OpenLane estimates net delay while it does resizing/repairing a design ? I suppose there exists something like "wire net model" however I would like to know if is there any degree of freedom to manipulate it ? The clue is that before routing I have a clean STA report, however afrer routing and SPEF I have got some hold violations. I found a parameter named WIRE_RC_LAYER set to met1 by default. Does the parameter set the default metal layer for pre-routing RC delay modeling (wire net model) ? What about changing it to the higher metal layers in order to diminish the delay thus inform the resizer to pay more attention to the hold violations? Does it make sense ?