Without IP cores, constraints are in one set. The Vivado IDE reads XDC files or Tcl scripts in list order, top to bottom.
Follow these steps to change the file order in the Vivado IDE:
- Select the file in the constraints set.
- Move the file to the desired location in the list.
For example, in the following figure, wave_gen_pin.xdc was moved before wave_gen_timing.xdc using drag and drop.
Figure 1. Changing XDC File Order in the Vivado IDE Example
The equivalent Tcl command is:
reorder_files -fileset constrs_1 -before [get_files wave_gen_timing.xdc] \
[get_files wave_gen_pins.xdc]| File | Order (Before) | Order (After) |
|---|---|---|
| wave_gen_timing.xdc | 1 | 2 |
| wave_gen_pins.xdc | 2 | 1 |
In non-project mode, the order of read_xdc
calls determines the evaluation order of the constraint files.