You can import an HLS function into your Vitis Model Composer design using the xmcImportFunction
command. Importing C/C++ Code as Custom Blocks describes this. You can
simulate the block along with other blocks available in the Model Composer HLS library
and generate HLS code from a system comprised of one or more imported HLS function
blocks and other HLS blocks from the HLS library,except for HLS Kernel block. Vitis Model Composer can also import HLS kernels. This
section describes HLS Kernels and how it is different from an HLS function.