I am new to EDI tool, right now I am seeing big clock skew on our designs with EDI flow (we are using foundation flow). After debugging this skew problem, I found that clock skew is due to miscorrelation between timing engines at different stages.
For example on a routed database
(a) IQRC extraction with "default" timing engine reports 230ps skew
(b) IQRC extraction with "signal storm" timing engine reports 305ps skew
But if I run "ckECO -postRoute -useSpecFileCellsOnly", tool starts skew optimization from 190ps skew. So looks like CTS uses a totally different timing engine and its hard to achieve good skew until ckECO sees correct skew. Please let me know if there are any tricks/workaround to run ckECO based on signoff timing engine or optimizing skew.
Thankyou in advance for any suggestions..