Hi all, I am trying to run HDL simulations for the Caravel with user project. I am following the io_ports_tb testbench. However, I am facing a few issues when compile these files in Modelsim: • How is the lib.ref in ``include "libs.ref/sky130_fd_io/verilog/sky130_fd_io.v"` resolved? Should I manually modify the path? • I am trying the find these files such as

libs.ref/sky130_fd_sc_hd/verilog/primitives.v

but it does not exist even in the latest skywater PDK. Is there anyway to get these files? • It seems that the file is a custom wrapper for Caravel ``include "libs.ref/sky130_fd_io/verilog/sky130_ef_io__gpiov2_pad_wrapped.v"` . But I have no clue where I can find it. These are blocking my simulations. If you know any solution, please feel free to tell me. Thank you all in advance. I believe Caravel is a nice project.

• The underlying assumption is that you have the skywater-pdk installed using open-pdks. And, during the iverilog compilation step, the PDK root is included. So, this path is resolved to

$PDK_ROOT/libs.ref/sky130_fd_io/verilog/sky130_fd_io.v

• After installing the skywater-pdk using open_pdk, you should have the

primitives.v

and the

sky130_ef_io__gpiov2_pad_wrapped.v

You can check this section for instructions on setting up the pdk : https://github.com/efabless/caravel/tree/develop#getting-started