When I run NGDBuild, I receive the following warning:
"WARNING:basnu:159 - Attribute "TNM_NET" on "CLK" is on the wrong type of object.
Please see the "Attributes, Constraints, and Carry Logic" section of the Libraries Guide for more information on this attribute."
I attached TNM_NET on the net between clock port and clock buffer in a mentor schematic. Then I run mentor edif writer (pld_men2edif). The resulting edif contains TNM_NET attached to both PORT and NET.
This is a result of the way Mentor attaches properties, and ends up attaching the property to two places: the PORT and the NET.
There is currently no way to prevent Mentor's EDIF writer (ENWRITE) from annotating this attribute to the two places.
You can safely ignore this warning from NGDBuild, as the attribute is attached to the proper place and will get processed properly.