Preserving XDC Macros through opt_design - 2021.2 English

Vivado Design Suite User Guide: Using Constraints (UG903)

Document ID
UG903
Release Date
2021-11-17
Version
2021.2 English

opt_design is free to optimize and remove LUTs that belong to an XDC macro despite the RLOC constraint. To prevent opt_design from optimizing the logic inside an XDC macro, it is necessary to set the property DONT_TOUCH to TRUE on all the cells that belong to the XDC macro. The DONT_TOUCH property can be set either through RTL or XDC.