General Description: I have instantiated a specific Xilinx component (i.e., BUFG, BUFGDLL), but after the Optimize command in synthesis is run, my instantiated component disappeares. Did I instantiate incorrectly? Is there an attribute I should use when instantiating Xilinx-specific components?
Anytime a Xilinx-specific component is instantiated, that component should never be removed by synthesis. If an instantiated component is being removed or optimized to a different component, this happens because of a bug in the Synthesis tool.
The following attribute can be used to force Optimize not to touch a particular instance:
After performing a "Read", but before using the "Optimize" command, either use the following in the TCL script, or type it in the GUI command window: