enforce equidistant placement

[salmen20]

Hello everyone,
I'm working on a design in OpenROAD and I would like to place certain cells at equal distances from a reference cell. Can anyone guide me on how to enforce equidistant placement for cells relative to another reference cell within the OpenROAD flow? Are there specific constraints or placement strategies I can use to achieve this?
Thanks.

[maliberty]

There is no such constraint. Can you pre-place these instances?

[salmen20]

How can i do that ? you mean placing them manually ?
Thanks

[maliberty]

Either through a floorplan DEF where they are placed and marked FIXED or through tcl, eg

proc place_inst { inst x y } {
  set db_inst [[ord::get_db_block] findInst $inst]
  $db_inst setLocation $x $y
  $db_inst setOrient R0
  $db_inst setPlacementStatus LOCKED
}

[salmen20]

I found an example with the chameleon design i guess it can solve my probem but will take a lot of time as i have a lot of instance , i will try to find a way to automate that , the question here in order to get those name will be by running the synth getting those names , then running floorplan with the MACRO_PLACEMENT variable ?

[maliberty]

You would need the post-synth names. If these are macros then you could use MACRO_PLACEMENT

[salmen20]

I will try that and see , Thank you