The-OpenROAD-Project
[Feature request] Routing only specific nets
Can OpenRoad implement a TCL command for routing only specific nets? Looks like FastRoute will route the nets it has been asked to route. So this should be a fairly simple feature to implement.
The reason for this is that I wanted to extend OpenLane to route some PDN/Mixed signals. However, it seems that the only reasonable way to do this is by asking FastRoute to route these signals before Place. Any suggestions?
PDN signals are routed by pdngen not fastroute. Would you describe further what you are trying to do. Note that you would also have to enhance the detailed router as well.
I am trying to route mixed signals from PADs to custom GPIOs/DACs/ADCs located inside a Caravan template without any manual work. For this I made a custom NONDEFAULTRULE in LEF and I can observe that these rules are followed by both global and detailed router. The result GDS also follows the NONDEFAULTRULE after updating to latest version.
However, since the timings for these nets are disabled in SDC the observed routes are not the shortest paths, since there signals between PADs and GPIO module which are routed with shortest path, as they have timings enabled.
So I am currently trying to implement GPIO routing in the floorplanning stage, before placement (as the placement of GPIO is done manually) and then fixing them, preventing routers from modifying these nets. This would also allow user to see the nets and analyze the optimality before fully completing the flow.
I could just remove all nets from the DEF, do the routing, then add the routed nets back to DEF, but I thought if the router allowed to select the nets to route or prioritize this would solve this issue.
Maybe there is better solution for this, but I couldn't figure out a way to do it.
It's a niche use model so it has a low priority. I'll assign it but I can't guarantee any timeline.