What is the file XXXXXXw.vhd that came with my core?
Our base cores are designed such that there are no bi-directional pins on the interface. A *w.vhd file is provided as a “tri-state wrapper” to “wrap” the base core and provide bi-directional pins. Additionally, historically some place and route tools may break apart buses (std_logic_vector) into separate bits. In these cases a *pw.vhd file may be provided as a “post-route wrapper” to collapse the bits so that the original CAST provided testbench can be used. This is generally a legacy item since most tools do currently output buses.
