Hey Park
Adding few MATLAB documentations which will be a good starting point for using S-Function in C/C++
- https://www.mathworks.com/help/simulink/create-cc-s-functions.html
- https://www.mathworks.com/help/simulink/slref/sfunctionbuilder.html
- https://www.mathworks.com/help/simulink/s-function-builder_mw_04a1b631-c9e0-4236-9eb5-e091b68ead09.html
I hope you find it helpful