open-source-silicon.dev

<@U016EM8L91B> Any idea how to link sky130 PDK to a new xschem schematics ?

<@U01F36ZPD3Q> In case you haven't seen this, I found it helpful: <https://github.com/bluecmd/learn-sky130/blob/main/schematic/xschem/getting-started.md>

<@U017FMP2MJN> ok, thanks.  <https://github.com/bluecmd/learn-sky130/blob/main/schematic/xschem/getting-started.md#creating-the-schematic>

<@U017FMP2MJN> Do I need
```append XSCHEM_LIBRARY_PATH :${XSCHEM_SHAREDIR}/xschem_library```
 ?  What is  `XSCHEM_SHAREDIR` ?

Sorry TBH I don't know, but I followed the instructions and it pretty much worked I think.

<@U01F36ZPD3Q>, XSCHEM_SHAREDIR is xschem's install location, where it looks for all its files, in particular $XSCHEM_SHAREDIR/xschem_library contains the devices/ library with all the technology-independent primitives, like spice resistors, voltage sources, ideal capacitors etc.

so if you set XSCHEM_LIBRARY_PATH as a ':' separated list of directories to look for components you certainly want to include the devices/ library.

```[phung@dell ~]$ ls /usr/local/share/xschem/
break.awk                   gschemtoxschem.awk        order_labels.awk  symgen.awk   vhdl.awk
change_index.tcl            hspice_backannotate.tcl   rawtovcd          systemlib    <http://xschem.help|xschem.help>
convert_to_verilog2001.awk  <http://keys.help|keys.help>                 resources.tcl     tedax.awk    xschem_library
flatten.awk                 make_sym.awk              sort_labels.awk   utile        xschemrc
flatten_tedax.awk           ngspice_backannotate.tcl  spice.awk         verilog.awk  xschem.tcl
[phung@dell ~]$ ```

<@U01819B63HP> in my case, is `XSCHEM_SHAREDIR` equivalent to `/usr/local/share/xschem` ?

<@U01F36ZPD3Q>, yes this is the default, in your xschemrc you can either use $XSCHEM_SHAREDIR/xschem_library or /usr/local/share/xschem/xschem_library

when you place a voltage source, it will saved in the schematic as 'devices/vsource.sym' , this allows xschem to find the object in the filesystem, by looking in the list of XSCHEM_LIBRARY_PATH paths

<@U01F36ZPD3Q> this <https://github.com/StefanSchippers/xschem_sky130|repository> contains the xschem components for the sky130 process, and the xschemrc in the xschem_sky130 directory is configured to run xschem with the correct paths. There are some example designs.