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I remeber seeing this variable in synthesis `SYNTH_CAP_LOAD` here:
<https://openlane.readthedocs.io/en/latest/configuration/README.html#:~:text=SYNTH_CAP_LOAD,Default%3A%2033.5%20ff>)
Is this what you mean? Setting this variable will also affect the STA I suppose.
Sorry if I am digressing from what you are asking.

Hi <@U01TJMPKS74> indeeed there is a macro which defines that

```SYNTH_CAP_LOAD 	The capacitive load on the output ports in femtofarads.
(Default: 33.5 ff)```

I was wondering if it is possible tell the OpenSTA, that the load capacitance is  the input capacitance of a subsequent gate, specifying the gate name/input

Ah right, understood. The OpenSTA datasheet tells me that `set_fanout_load` command is ignored. That is likely to be analogous to the `set_driving_cell`

So, there is one intermediate solution I think. If You set those macros

```set ::env(PL_RESIZER_BUFFER_INPUT_PORTS) "1"
set ::env(PL_RESIZER_BUFFER_OUTPUT_PORTS) "1"```

each input and each output will be buffered by a buffer gate so I think it would be ok to put the input capacitance of this buffer

the question is how to get it ? It can be found in the lib file of sky130 PDK however is difficult to deduce which one to choose because there are many variants

As a side-note: As per the documentation, `PL_RESIZER_BUFFER_OUTPUT_PORTS` is set to '1' by default.

You can set which library to use for resizer optimizations: <https://openlane.readthedocs.io/en/latest/configuration/README.html#:~:text=STD_CELL_LIBRARY_OPT,during%20resizer%20optimizations>.

But, I don't think you can force it to use a particular cell like
```SYNTH_DRIVING_CELL : The cell to drive the input ports.
(Default: sky130_fd_sc_hd__inv_1)```


what I want is to assign the outpud load based on a particular gate

I would like to substitute the 0.1 value with the value of the input buffer

ok, let me explain more: so my output is connected to an input buffer of a subsequent stage thats why I call it input

I would like to use rather a name of the buffer than the value to make it more flexible for example in case of corner analysis

I am sorry I don't find a way to do that. Someone else might be able to find one.

set_load - see <https://github.com/The-OpenROAD-Project/OpenSTA/blob/master/doc/OpenSTA.pdf>

If you need to have a custom SDC please read OpenSTA doc posted by Matt