Writes constraints to a Xilinx Design Constraints (XDC) file. The default file extension for a XDC file is .xdc.
write_xdc [‑no_fixed_only] [‑constraints <arg>] [‑cell <arg>] [‑sdc] [‑no_tool_comments] [‑force] [‑exclude_timing] [‑exclude_physical] [‑add_netlist_placement] [‑logic_function_stripped] [‑type <args>] [‑write_id] [‑exclude_cells <args>] [‑quiet] [‑verbose] [<file>]
||Export fixed and non-fixed placement (by default only fixed placement is exported)|
||Include constraints that are flagged invalid Values: valid, invalid, all Default: valid|
||Hierarchical cell for which constraints are exported.|
||Export all timing constriants in SDC compatible format.|
||Don't write verbose tool generated comments to the xdc when translating from ucf.|
||Overwrite existing file.|
||Don't export timing constraints.|
||Don't export physical constraints.|
||Export netlist placement constraints.|
||Write disable_timing constraints which are associated with having previously run write_edif with its -logic_function_stripped option.|
||Types of constraint to export. Values: timing, io, misc, waiver and physical. If not specified, all constraints will be exported.|
||Write position number for timing constraints|
||Don't export constraints scoped to or below the specified hierarchical cell(s).|
||Ignore command errors|
||Suspend message limits during command execution|
||Output constraints to the specified XDC file.|
write_xdccommand writes the constraints to the specified file in the same order they are added to or executed in the design.
write_xdc command lets you write invalid XDC constraints so that you can quickly report constraints that have been ignored by the Vivado® Design Suite due to a problem with the way the constraint is written or applied. This is useful for debugging constraint files applied in specific designs.
write_xdccommand will not convert all UCF constraints into XDC format, and is not intended to automatically convert UCF based designs to XDC. Refer to the Vivado Design Suite Migration Methodology Guide (UG911) for more information on migrating UCF constraints to XDC.
-no_fixed_only - (Optional) Export both fixed and unfixed placement
LOCs to the constraint file being written. By default only the fixed LOCs will be
written to the XDC file. Fixed LOCs are associated with user-assigned placements,
while unfixed LOCs are associated with tool assigned placements.
-constraints <arg> - (Optional) Export constraints that are
flagged valid, invalid, or all constraints (both valid and invalid). The default
behavior is to export only valid constraints to the XDC file. Valid values are
VALID, INVALID, or ALL.
-cell <arg>- (Optional) The name of a hierarchical cell in the current design to export the constraints from. The constraints will be written to the specified XDC file relative to the specified cell.
-exclude_cells <arg> - (Optional) Do not export constraints
scoped to or below the hierarchical cells listed in <arg>. All other constraints
are exported including constraints which refer hierarchically to the cells or cell
contents but are scoped above the specified cells.
-sdc - (Optional) Export only the timing constraints in a file
format that is 100% SDC compatible from the current design. Does not export any
other defined constraints.
-no_tool_comments - (Optional) Do not add tool generated comments
into the XDC file.
-force - (Optional) Overwrite a file of the same name if one already
-exclude_timing - (Optional) Do not export timing constraints. This
results in an XDC file that contains only physical constraints.
-exclude_physical - (Optional) Do not export physical constraints.
This results in an XDC file that contains only timing constraints.
-add_netlist_placement - (Optional) Include placement constraints
that are defined in the netlist file as part of the written XDC file.
-type <arg> - (Optional) Specifies the types of constraint to
export. Valid values are: timing, io, misc, waiver and physical. Multiple types can
be specified at one time. If the type is not specified, all constraints will be
-logic_function_stripped - (Optional) Includes the
set_disable_timing constraints which are needed to preserve the
constants propagation and timing signoff after stripping the logic function of the
LUTs. It should be used in association with
-write_id - (Optional) Includes the constraint position number
before each timing constraint. The position number if also reported inside the
Timing Constraints Editor (TCE) and some of the Methodology violations.
-quiet- (Optional) Execute the command quietly, returning no messages from the command. The command also returns TCL_OK regardless of any errors encountered during execution.
-verbose- (Optional) Temporarily override any message limits and return all messages from this command.
<file>- (Required) The file name of the XDC file to write.
write_xdc -no_fixed_only -constraints all C:/Data/design.xdc
write_xdc -constraints invalid C:/Data/bad_constraints.xdc
write_xdc -exclude_timing -add_netlist_placement C:/Data/physical.xdc