Netlist extractor SPICE

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Netlist extractor SPICE#

This notebook demonstrates how to extract the SPICE netlist of a Component or a GDS file using gdsfactory. It uses the :func:~get_netlist and :func:~get_l2n functions from the gplugins.klayout module to extract the netlist and connectivity mapping, respectively. It also uses the plot_nets function to visualize the connectivity.

import pathlib

from gdsfactory.samples.demo.lvs import pads_correct, pads_shorted

from gplugins.klayout.get_netlist import get_l2n, get_netlist
from gplugins.klayout.netlist_spice_reader import (
    GdsfactorySpiceReader,
)
from gplugins.klayout.plot_nets import plot_nets

Sample layouts#

We generate a sample layout using pads_correct and write a GDS file.

c = pads_correct()
gdspath = c.write_gds()
c.show()
c.plot()
../_images/e4030f60ec271ea2544ab93dad3d50144646ed210e049a46b10e6e8650945d40.png

We obtain the netlist using KLayout by simply calling the :func:~get_netlist function from the gplugins.klayout module. The function takes the path to the GDS file as an argument and returns the netlist as a kdb.Netlist object.

netlist = get_netlist(gdspath)
print(netlist)

Wrote '/home/runner/work/gplugins/gplugins/gplugins/klayout/layers.lyp'
/home/runner/work/gplugins/gplugins/gplugins/klayout/d25/generic.lyd25
Wrote '/home/runner/work/gplugins/gplugins/gplugins/klayout/tech.lyt'
circuit taper_L10_W100_W10_LNon_43bc52bd ($1=$1);
end;
circuit pad_S100_100_LMTOP_BLNo_163fd346 ($1=$1,$2=$2);
end;
circuit pads_correct_Ppad_CSmetal3 ();
  subcircuit pad_S100_100_LMTOP_BLNo_163fd346 $1 ($1='tl,tr',$2=tl);
  subcircuit taper_L10_W100_W10_LNon_43bc52bd $2 ($1='tl,tr');
  subcircuit pad_S100_100_LMTOP_BLNo_163fd346 $3 ($1='tl,tr',$2=tr);
  subcircuit taper_L10_W100_W10_LNon_43bc52bd $4 ($1='tl,tr');
  subcircuit pad_S100_100_LMTOP_BLNo_163fd346 $5 ($1='bl,br',$2=br);
  subcircuit pad_S100_100_LMTOP_BLNo_163fd346 $6 ($1='bl,br',$2=bl);
  subcircuit taper_L10_W100_W10_LNon_43bc52bd $7 ($1='bl,br');
  subcircuit taper_L10_W100_W10_LNon_43bc52bd $8 ($1='bl,br');
end;

The connectivity between the components in the GDS file can be visualized using the :func:~plot_nets function from the gplugins.klayout module. The function takes the path to the GDS file as an argument and plots the connectivity between the components in the GDS file.

l2n = get_l2n(gdspath)
cwd = pathlib.Path.cwd()
filepath = cwd / f"{c.name}.txt"
l2n.write_l2n(str(filepath))
plt = plot_nets(
    filepath, spice_reader=GdsfactorySpiceReader(components_as_subcircuits=[c.name])
)
plt.savefig(f"{c.name}.png")
plt.show()

Wrote '/home/runner/work/gplugins/gplugins/gplugins/klayout/layers.lyp'
/home/runner/work/gplugins/gplugins/gplugins/klayout/d25/generic.lyd25
Wrote '/home/runner/work/gplugins/gplugins/gplugins/klayout/tech.lyt'

Warning: Element type 'X' ignored in /tmp/tmp889d7c5o.sp, line 23
Warning: Element type 'X' ignored in /tmp/tmp889d7c5o.sp, line 29
Warning: Element type 'X' ignored in /tmp/tmp889d7c5o.sp, line 35
Warning: Element type 'X' ignored in /tmp/tmp889d7c5o.sp, line 41
Warning: Element type 'X' ignored in /tmp/tmp889d7c5o.sp, line 47
Warning: Element type 'X' ignored in /tmp/tmp889d7c5o.sp, line 53
Warning: Element type 'X' ignored in /tmp/tmp889d7c5o.sp, line 59
Warning: Element type 'X' ignored in /tmp/tmp889d7c5o.sp, line 65
../_images/1b7ddafb590e41317fc39622c49b31fb73389837cfd2f10a91e897edc19ec66a.png

The same steps as above are done for a shorted case.

c = pads_shorted()
gdspath = c.write_gds()
c.plot()
../_images/23da6c768d9b797ab5cb407e4f768407bcf3d55306c77c7313eed6a1b2c55af1.png 
netlist = get_netlist(gdspath)
print(netlist)

Wrote '/home/runner/work/gplugins/gplugins/gplugins/klayout/layers.lyp'
/home/runner/work/gplugins/gplugins/gplugins/klayout/d25/generic.lyd25
Wrote '/home/runner/work/gplugins/gplugins/gplugins/klayout/tech.lyt'
circuit taper_L10_W100_W10_LNon_43bc52bd ($1=$1);
end;
circuit pad_S100_100_LMTOP_BLNo_163fd346 ($1=$1,$2=$2);
end;
circuit pads_shorted_Ppad_CSmetal3 ();
  subcircuit pad_S100_100_LMTOP_BLNo_163fd346 $1 ($1='bl,br,tl,tr',$2=tl);
  subcircuit taper_L10_W100_W10_LNon_43bc52bd $2 ($1='bl,br,tl,tr');
  subcircuit pad_S100_100_LMTOP_BLNo_163fd346 $3 ($1='bl,br,tl,tr',$2=br);
  subcircuit taper_L10_W100_W10_LNon_43bc52bd $4 ($1='bl,br,tl,tr');
  subcircuit pad_S100_100_LMTOP_BLNo_163fd346 $5 ($1='bl,br,tl,tr',$2=tr);
  subcircuit taper_L10_W100_W10_LNon_43bc52bd $6 ($1='bl,br,tl,tr');
  subcircuit pad_S100_100_LMTOP_BLNo_163fd346 $7 ($1='bl,br,tl,tr',$2=bl);
  subcircuit taper_L10_W100_W10_LNon_43bc52bd $8 ($1='bl,br,tl,tr');
end;

l2n = get_l2n(gdspath)
filepath = cwd / f"{c.name}.txt"
l2n.write_l2n(str(filepath))
plt = plot_nets(
    filepath, spice_reader=GdsfactorySpiceReader(components_as_subcircuits=[c.name])
)
plt.savefig(f"{c.name}.png")
plt.show()

Wrote '/home/runner/work/gplugins/gplugins/gplugins/klayout/layers.lyp'
/home/runner/work/gplugins/gplugins/gplugins/klayout/d25/generic.lyd25
Wrote '/home/runner/work/gplugins/gplugins/gplugins/klayout/tech.lyt'
Warning: Element type 'X' ignored in /tmp/tmp18dk3bga.sp, line 23
Warning: Element type 'X' ignored in /tmp/tmp18dk3bga.sp, line 29
Warning: Element type 'X' ignored in /tmp/tmp18dk3bga.sp, line 35
Warning: Element type 'X' ignored in /tmp/tmp18dk3bga.sp, line 41
Warning: Element type 'X' ignored in /tmp/tmp18dk3bga.sp, line 47
Warning: Element type 'X' ignored in /tmp/tmp18dk3bga.sp, line 53
Warning: Element type 'X' ignored in /tmp/tmp18dk3bga.sp, line 59
Warning: Element type 'X' ignored in /tmp/tmp18dk3bga.sp, line 65
../_images/119bb42f04bd136bf4d79069df1a16fddb2e41239ce8d3e9f8330c8e00f65f71.png
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