Use XDC macros to assign relative placement to cells after synthesis. Macros share many characteristics with RPMs, but they are design objects that you can modify interactively using XDC and Tcl. Create macros from leaf cells that you group together with relative placement constraints.
Manage RPMs in HDL code and manage macros with XDC constraints. You cannot automatically convert RPMs to macros, and you cannot automatically annotate macros back into HDL code. Unlike macros, RPMs are not objects, and you cannot use XDC macro commands on them.
| Definition | RPMs | Macros |
|---|---|---|
| HDL Attributes | XDC constraints | |
| Post-synthesis access | Read-only | Read-write |
| Hierarchical | Yes (H_SET or
HU_SET) |
No |
| RLOC targets | Non-leaf and leaf cells | Leaf cells only |
| Site type mixing | Yes, using the RPM_GRID
attribute |
Yes, using update_macro
-absolute_grid
|
| Accessible as objects | No | Yes |
| Where stored | In netlist | In XDC or Tcl scripts |