XDC macros enable assignment of relative placement to cells after synthesis. Macros have many characteristics similar to RPMs, but are design objects that can be modified interactively using XDC and Tcl. Macros are created from leaf cells that are grouped together with relative placement constraints.
While RPMs are managed in HDL code, macros are managed using XDC constraints. RPMs cannot be automatically converted to macros. Similarly, macros cannot be automatically annotated to HDL code. Unlike macros, RPMs are not objects, and the XDC macro commands cannot be used on RPMs.
| RPMs | Macros | |
|---|---|---|
| Definition | HDL Attributes | XDC constraints |
| Post-Synthesis Access | Read-only | Read-write |
| Hierarchical | Yes (H_SET/HU_SET) | No |
| RLOC Targets | Non-leaf and leaf cells | Leaf cells only |
| Site Type Mixing Allowed | Yes, using RPM_GRID attribute |
Yes, using |
| Accessible as objects | No | Yes |
| Where stored | In netlist | In XDC or Tcl scripts |