Reply To: export cells into an existing gds

[paul]

Hello Ronald,

Yes I think that it does cover it, because in a normal use case I would instantiate the new cells as top cells and then instantiate them in the hierarchy manually in Klayout (usually by replacing old cells).

import nazca as nd

# Level 1 Cells
with nd.Cell(name='B') as cellB:
    nd.strt().put()
with nd.Cell(name='C') as cellC: 
    nd.bend(angle=90).put()
with nd.Cell(name='D') as cellD: 
    nd.taper(layer=2).put()
    
# Level 0 Cell (top cell)
with nd.Cell(name='A') as cellA: 
    cellB.put()
    cellC.put(10)
    
nd.export_gds(filename='example.gds', topcells=cellA)

# Load example.gds, and add cellD as a top cell
cell_dict = nd.load_gds(filename='example.gds', 
                        asdict=True, 
                        topcellsonly=True)

cell_list=list(cell_dict.values())
cell_list.append(cellD)
nd.export_gds(filename='example.gds', topcells=cell_list)

In the example above, I could either manually instantiate cell D as a new cell in cell A, or replace of the existing cells by cell D after the second export.

To push things further how could I automatically replace the cells in Nazca? In the example below I tried to replace cell C with a new version in the cell dictionary. It does not replace the old cell but instantiate it as a new top cell.

import nazca as nd

# A new version of cellC 
with nd.Cell(name='C$1') as newC:
    nd.bend(angle=30, layer=3).put()

# topcellsonlly flag set to False to import old cell C 
cell_dict = nd.load_gds(filename='example.gds', 
                        asdict=True, 
                        topcellsonly=False)
    
# replace cell C in cell_dict   
cell_dict['C'] = newC
# get new list of cells 
cell_list=list(cell_dict.values())

nd.export_gds(filename='example_v2.gds', topcells=cell_list)

The obvious answer would be to recreate the whole hierarchy, i.e in this case:

newCellA
    newCellC
    oldCellB
oldCellD

But this can get tedious if you need to replace a cell in the lowest level of the hierarchy, or even worse if the cell is instantiated in different ‘tree branches’.

Thanks,

Paul

nazca version: 0.5.7