open-source-silicon.dev

Hi , how to supply dont_touch instances in opelane - so that yosys doesnt remove some hierarchies ? Thanks

not black box. For eg , some hierarchies will be deleted by Yosys if no relevance to output ports found....But i would need them since initial RTL stage

that i need to edit inside RTL.  Is there any seperate YOSYS command ? commercial tools have set_dont_touch kinda thing...

But it does not make sense. If your module does not output anything, then why do you even have it?

as i mentioned initial RTL -- in exploration phase  now --

• The `keep` attribute on cells and wires is used to mark objects that should never be removed by the optimizer. This is used for example for cells that have hidden connections that are not part of the netlist, such as IO pads. Setting the `keep` attribute on a module has the same effect as setting it on all instances of the module.
• The `keep_hierarchy` attribute on cells and modules keeps the `flatten` command from flattening the indicated cells and modules.
