Context
Today the layer RC values used by EST are generated using a series of scripts that compile RCX information for a certain technology into a rough estimation. What happens today:
- Run many designs from one PDK and record for each net:
- cap & res;
- wire length per layer;
- Formulate a linear regression model.
General Problem
The data we use for the linear regression model, gives us an average over different contexts, but also “hides” differences in topology and layer assignment which may lead to inconsistencies in the parasitics estimated at global routing.
Suggested Solution
Improve the regression's results by using a more granular input: instead of relying on the total RC values of each individual net, formulate the linear regression model from the segments of each net for a more precise approximation. For that, use the .spef file data that can be kept inside ODB.
Context
Today the layer RC values used by EST are generated using a series of scripts that compile RCX information for a certain technology into a rough estimation. What happens today:
General Problem
The data we use for the linear regression model, gives us an average over different contexts, but also “hides” differences in topology and layer assignment which may lead to inconsistencies in the parasitics estimated at global routing.
Suggested Solution
Improve the regression's results by using a more granular input: instead of relying on the total RC values of each individual net, formulate the linear regression model from the segments of each net for a more precise approximation. For that, use the .spef file data that can be kept inside ODB.