Displaying net name in a DEF

nanor000

Hi,
I am able to read a DEF+LEF successfully in klayout. To display the net name, I can select the net, press Q, then press the button "User Property". I don't want to see all the net names displayed. Just the name of the one that is selected, eventually with a press of a key
I've tried to assign the letter W to the function "cell_user_properties" using the setup dialog (in Customize menu) , but nothing happens.
What is the best/quickest way to display the net name in a window after a keypress (or in the bottom of the main window) for a selected net ?

Thank you

Ronan

Matthias

Hi Ronan,

there is no such feature yet as user properties are rarely used in the GDS2 world that KLayout stems from. After all, KLayout is not a LEF/DEF viewer, but a mask layout tool.

It is possible to install a callback through a script that tracks the selection and displays a specific user property as the net name in the status bar (this will hide the selection information). Here is some sketch:

# NOTE: this method needs to be run once to install the 
# callbacks. This is done automatically if you configure
# the script as "autorun".

# TODO: change to the property key you used when importing LEF/DEF
net_property_key = 1

def selection_changed():
  cv = pya.LayoutView.current()
  net = None
  if cv is not None:
    for o in cv.each_object_selected():
      if not o.is_cell_inst():
        net = o.shape.property(net_property_key)
        if net is not None:
          break
    if net is not None:
      pya.MainWindow.instance().message("Net: " + str(net), -1)

def current_view_changed():
  cv = pya.LayoutView.current()
  if cv is not None:
    cv.on_selection_changed += selection_changed

mw = pya.MainWindow.instance()
mw.on_current_view_changed += current_view_changed
current_view_changed()

Please note the TODO comment.

Matthias

nanor000

Thank you. I'll try that asap

StefanThiede

Could you elaborate on the use-case ?
On top of layout viewing, openroad -gui also has netlist and timing browsers ...

Matthias

Plus they are in touch with me to optimize their viewer

nanor000

Use case: quickly debug DRC errors related to Non Default Rule (NDR) routing - Using a DEF can be much more effcient to identify the net(s) causing the issues