Abutted floorplan
Beginner
Blocks packed edge to edge, with no gaps between them.
Novice
A floorplan in which blocks touch edge to edge with no channels between them. It saves area, but every connection between blocks must be planned through the blocks’ own pins.
Expert
No top-level logic or channels: signals that cross the chip, including the clock, route through the blocks, so they must be planned into each block up front.
Explained in Floorplanning (Design Flow).
See also: Hierarchical design (partitioning), Channel (macro channel).