we use encounter to implement most of our ECO's.
However, we have an ECO which requires too many gates.
We have heard that some people rip out a module,
and have the tool replace the module with the new netlist.
The question is what is the procedure to do that?
It is easy enough to locate the module in the netlist -
but beyound that - how do we ensure that all the gates are declared as "free" or spares.
then how do we place the new netlist in its place? (ps, i am not a backend guy - but this is my requirement)
In your ECO verilog netlist, just remove the module you want to get rid of from the netlist. When you import the ECO netlist and the old DEF into Encounter it will recognize that the gates in that module are no longer needed and mark them as spares. They can then be used for any newly added logic.
For more detail on how to perform ECOs, see Chapter 42 - ECO Flows in the Encounter Digital Implementation System User Guide.