As part of the design constraints, the waivers are automatically saved inside the checkpoint and restored from the checkpoint. Waivers are saved inside both the plain XDC and binary constraints.
Use write_xdc
and write_waivers
commands to export the waivers as a standalone XDC file. The
XDC can be reloaded inside Vivado tools with the read_xdc
or source
commands.
The write_xdc
command exports all the waivers
inside the XDC file along with all the design constraints. This includes the waivers
defined by the user and also the AMD IP waivers. The constraints
inside the XDC are in the same order as they have been applied to the design. To only
export the waivers, use the command line option -type
waiver
. For example:
write_xdc -type waiver -file waivers.xdc
create_waiver -internal
. User waivers
must never use the option create_waiver -internal
. This
option is exclusively reserved for AMD IP waivers.The write_waivers
command differs from write_xdc
because it only exports the user waivers and
provides more control and granularity. The AMD IP waivers are not
exported through write_waivers
. By default, all the
user CDC, DRC, and Methodology waivers are exported. Use the option -type
to only export CDC, DRC, or Methodology waivers.
For example, the command below exports all CDC waivers to the file waivers_cdc.xdc:
write_waivers -type CDC -file waivers_cdc.xdc
All the waivers for a particular check id can be exported with the option -id
. The example below export all the waivers for the Methodology check TIMING-15:
write_waivers -id TIMING-15 -file waivers_timing_15.xdc
The following table summarizes the differences between write_xdc
and write_waivers
commands with
regards to the user waivers and AMD IP waivers.
Vivado Command | Export User Waivers | Export AMD IP Waivers |
---|---|---|
write_xdc
|
Yes | Yes |
write_waivers
|
Yes | No |