AR# 56169


Vivado Constraints - CRITICAL WARNING: [Common 17-55] 'set_property' expects at least one object


How can Warnings and Critical Warnings like the following be resolved?

WARNING: [Vivado 12-180] No cells matched ' <object_name> '. [<XDC_file_path_and_name>.xdc:<line_number>]

WARNING: [Vivado 12-584] No ports matched ' <object_name> '. [<XDC_file_path_and_name>.xdc:<line_number>]

CRITICAL WARNING: [Common 17-55] 'set_property' expects at least one object. [<XDC_file_path_and_name>.xdc:<line_number>]


This warning and critical warning indicate that the object name specified in the constraint is not correct.

To correct it, go to the synthesized design and look for the actual name of the object in the netlist.

The following are some common causes of this issue.

  • XDC constraints are case sensitive. These warnings can occur if the case type of the object name in XDC is not the same as the signal in the RTL code.

For example, the following constraint causes the above Critical Warning.
set_property PACKAGE_PIN AF28 [get_ports CLK_66M_N]
in which the port name is actually "CLK_66M_n" in the RTL code.

  • Constraints in scoped XDC (IP XDC, OOC XDC, etc.) should use the object name and hierarchy within the specific scope.
    These warnings can occur when the hierarchy of the object name does not match the scope.

For example, for a register named a_reg in an IP instance "a_inst" under the top level, the following constraint in the IP XDC causes the above Critical Warning.
set_property INIT 1 [get_cells  a_inst/a_reg]
The correct constraint should be like this:
set_property INIT 1 [get_cells  a_reg]

AR# 56169
Date 08/08/2014
Status Active
Type General Article
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