AMD Answer 73167
All DPLL clock network deskew functions including the CLKIN_DESKEW/CLKFB_DESKEW inputs, deskew phase detector, deskew delay, deskew attributes, and the ZHOLD attribute are not supported. However, the deskew functionality is supported for CPM clocking.
This issue will not be fixed for the devices listed in the Errata Summary table.