NEED HELP WITH LAYER RE_MAPPING

Comments

• tnoradam

  May 2016 edited November -1

  I wrote script that loops through all flat-list cells and changes the layers of shapes
  over to a set of other layer. No problem, but I am struggling to change a layer
  parameter of PCELLs in the script. I can detect if a cell is a PCELL with myCell.is_pcell_variant?
  but the only thing I found to change the parameter is
  
  myCell.each_inst do |inst|
  myCell.change_pcell_parameter(inst,myPCParmName,newParm)
  puts "changing instance #{inst}"
  end
  
  (I have detected that the parameter is a layer by regex /[(][0-9]*\/[0-9]*[)]/)
  
  However, this does not update the PCELL at all.
  Am I doing something wrong here ?
  How would you do something like that ?
  
  Thanks.
  
  Thoams.
• Matthias

  May 2016 edited May 2016

  Hi Thomas,

  PCell updating is somewhat cumbersome. It would be easy if there was a method to translate a cell entirely, but there isn't. That is because although PCells are mapped to PCell variants, the PCell parameters are considered properties of instances.

  So you need to iterate the instances. Here is a recipe (untested):

  from_layer = ...    # A RBA::LayerInfo object with the layer to translate
  to_layer = ...      # A RBA::LayerInfo object giving the destination layer
  
  # we don't want to create a race between original and new cells so we first collect the normal cells
  normal_cells = []
  layout.each_cell do |cell|
    cell.is_pcell_variant? || normal_cells << cell
  end
  
  # then we walk through these and treat the PCell instances there
  normal_cells.each do |cell|
    cell.each_inst do |inst|
      if inst.is_pcell?
        param = inst.pcell_parameters_by_name
        update_needed = false
        param.each do |name, value|
          # This should work because
          #  1.) Every layer parameter is a RBA::LayerInfo object
          #  2.) The RBA::LayerInfo class implements a == operator
          if value.class == RBA::LayerInfo && value == from_layer
            param[name] = to_layer
            update_needed = true
          end
        end
        if update_needed
          inst.change_pcell_parameters(param)
        end 
      end
    end
  end
  

  As I said: this code is not tested but I am fairly sure this is the way it should work.

  Matthias
• tnoradam

  May 2016 edited November -1

  Hi Matthias,
  your code needed a little work here and there but I got it to work.
  a small hurdle is that we dont really care about the from_layer name, we
  only care that layer and layertype are correct. The individual designers that
  feed me the gds I am importing name the layers all differently, but they
  adhere to the agreed layer/type notation. I will figure it out though.
  
  i noticed in a test run, that for every modification of a PCELL, the original
  PCELL is shoved above the top cell. I cannot modify it anymore, delete
  by hand, or re-instance it.
  How would I purge these old original PCELLS programmatically ?
  
  THANK YOU SO MUCH FOR ALL YOUR HELP ! I was ready to pull my hair out
  on this one !
  
  Thomas.
• Matthias

  May 2016 edited May 2016

  Hi Thomas,

  I see I forgot a small detail above: the class of the parameter value needs to be checked too.

  If you have a layer and datatype you can simply create a RBA::LayerInfo object like this:

  from_layer = RBA::LayerInfo(layer, datatype)
  

  the name is ignored in that case because layer/datatype has higher priority.

  Regarding the top cells that pop up you can remove all PCell variants on top level afterwards. Because PCells may instantiate other PCells this step has to be repeated until there are no more cells to remove.

  The following is TESTED code:

  layout = RBA::CellView::active.layout
  
  from_layer = RBA::LayerInfo::new(2, 0)
  to_layer = RBA::LayerInfo::new(1, 0)
  
  # we don't want to create a race between original and new cells so we first collect the normal cells
  normal_cells = []
  layout.each_cell do |cell|
    cell.is_pcell_variant? || normal_cells << cell
  end
  
  # then we walk through these and treat the PCell instances there
  normal_cells.each do |cell|
    cell.each_inst do |inst|
      if inst.is_pcell?
        param = inst.pcell_parameters_by_name
        update_needed = false
        param.each do |name, value|
          # This should work because
          #  1.) Every layer parameter is a RBA::LayerInfo object
          #  2.) The RBA::LayerInfo class implements a == operator
          if value.class == RBA::LayerInfo && value == from_layer
            param[name] = to_layer
            update_needed = true
          end
        end
        if update_needed
          inst.change_pcell_parameters(param)
        end 
      end
    end
  end
  
  # remove top cells that popped up
  # This code emulates what KLayout does internally
  while !(cells_to_delete = layout.top_cells.select { |c| c.is_pcell_variant? }).empty?
    layout.delete_cells(cells_to_delete.collect { |c| c.cell_index })
  end
  

  Regards,

  Matthias