Different Innovus versions auto-(un)flatten ILMs differently

[harrisonliew]

E.g. it appears that 181_ISR2 does not auto flatten much more than 181_ISR3.

ISR2 errors on:

• set_dont_use
• everything in cts
• sourcing the pin & clock sdc's
• create_basic_path_groups
• write_ilm

but IS3 errors on only the first two.

Should we just always add flatten_ilm and unflatten_ilm to most of the steps, knowing that they won't do anything on flat designs?

[edwardcwang]

Would it be possible for you to elaborate a bit on what is meant by "auto flatten much more"?

[harrisonliew]

In the Innovus documentation, in the section Using the Flattened and Unflattened ILM States, it mentions at the end:

The Innovus super commands place_opt_design, routeDesign, and optDesign automatically manage the flattened and unflattened ILM states. For other commands, you should flatten or unflatten the design as required with the flattenIlm and the unflattenIlm commands.

So it appears that it does auto flatten but only at certain points in the flow.