Writes constraints to a Xilinx Design Constraints (XDC) file. The default file extension for a XDC file is .xdc.
Syntax
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] [‑quiet] [‑verbose] [<file>]
Usage
Name | Description |
---|---|
[-no_fixed_only]
|
Export fixed and non-fixed placement (by default only fixed placement is exported) |
[-constraints]
|
Include constraints that are flagged invalid Values: valid, invalid, all Default: valid |
[-cell]
|
Hierarchical cell for which constraints are exported. |
[-sdc]
|
Export all timing constriants in SDC compatible format. |
[-no_tool_comments]
|
Don't write verbose tool generated comments to the xdc when translating from ucf. |
[-force]
|
Overwrite existing file. |
[-exclude_timing]
|
Don't export timing constraints. |
[-exclude_physical]
|
Don't export physical constraints. |
[-add_netlist_placement]
|
Export netlist placement constraints. |
[-logic_function_stripped]
|
Write disable_timing constraints which are associated with having previously run write_edif with its -logic_function_stripped option. |
[-type]
|
Types of constraint to export. Values: timing, io, misc, waiver and physical. If not specified, all constraints will be exported. |
[-write_id]
|
Write position number for timing constraints |
[-quiet]
|
Ignore command errors |
[-verbose]
|
Suspend message limits during command execution |
[<file>]
|
Output constraints to the specified XDC file. |
Description
write_xdc
command writes the constraints to the specified file in the same order they are added to or executed in the design.The 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_xdc
command 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.Arguments
-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.
-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 exists.
-exclude_timing
- (Optional) Don't export timing constraints. This results in an XDC file that contains only physical constraints.
-exclude_physical
- (Optional) Don't 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 exported.
-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.
set_msg_config
command.Examples
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