General Description: In the M1 release, RPMs are converted early on into physical, or "hard", macros. As a result, it is not possible to merge more than one RPM that occupies part of the same range of CLB locations, an operation known as RPM "zippering".
For example, suppose you had a macro that RLOC'd FMAPS and HMAPS, and had another macro that RLOC'd flip-flops all to the same location. This would cause an error in PAR because it would not be able to merge both of the locations together.
The following error may be issued:
ERROR - Resolved that macro <instance_name> is unable to be placed due to other locked logic or prohibited sites. Refsite CLB_RxxCx is unavailable.
The only work-around is to manually merge the RPMs you wish to constrain to the same range into a single macro in your schematic.