Any logic that must be packed together must be placed in the same group, whether it is static or reconfigurable. For example, if a LUT and a flip-flop are expected to be placed within the same slice, they must be within the same partition. Partition boundaries are barriers to optimization.
For RPs that include I/O, Clocking, and GT resources, it might be necessary to
instantiate any I/O buffers that are automatically inferred by the tools inside that RP
level. For example, if
GT_COMMON is in an RP, the
IBUFDS_GTE needs to be instantiated. If the
associated I/O buffer is in the top-level/static portion, it cannot be packed.