Hi how to supply dont touch instances in opelane so that yos

Question

Hi how to supply dont touch instances in opelane so that yosys doesnt remove some hierarchies Thanks

Vijayan Krishnan · Answer

Are you asking about black box

Ryan R · Answer

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

Arman Avetisyan · Answer

keep

Arman Avetisyan · Answer

verilog attribute

Ryan R · Answer

that i need to edit inside RTL Is there any seperate YOSYS command commercial tools have set dont touch kinda thing

Arman Avetisyan · Answer

Probably setattr

Arman Avetisyan · Answer

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

Ryan R · Answer

as i mentioned initial RTL in exploration phase now

Ryan R · Answer

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

Ryan R · Answer

now need to check how to apply