XNFPrep issues the following on an Autologic design:
XNFPREP ERROR 3527: The pad `BURN/RUBBER' is connected to the following invalid symbol pins:
Symbol Type = DFF ; Pin Name = D; Symbol Name = BURN/RUBBER
A pad can be connected only to the input pin of input symbols/clock buffers (such as, the `I` pin of IBUF), and the output pin of output symbols/PULLUPs/PULLDOWNs (such as, the `Q' pin of OUTFF).
In Mentor, when creating a custom symbol, the schematic underneath must have PORTs to link the underlying nets to their associated symbol pins. Mentor's Autologic program takes a designer's HDL and translates it to a schematic. In its Set Technology Environment dialog, Autologic gives the user the following three choices:
PADs on top level, PORTs on all others PADs on all levels PORTs on all levels
Selecting the option "PADs on all levels" may cause XNFPREP Error 3527, as this will cause external pads to be created as connections between hierarchial levels.
In Autologic, under the SETUP menu, there is a Set Tech Environment selection. A popup will appear that will allow the user to set the parttype and set a few other options. At the bottom of this popup, there should be a section named Schematic configuration file that contains the three above options. Select either "PADs on top level, PORTs on all others" or "PORTs on all levels".
In some of the earlier verions of the xc2000, xc3000, and xc4000 synthesis libraries for Autologic, these options were not available. In this case, you can aquire the newest libraries from Mentor. See Solution 608, "How to obtain the latest version of the Autologic libraries for Xilinx," for more information.
The version of the library may be determined by going to the IDEA tree where the Autologic libraries are located and reading the README file under the appropriate library directory. The place where the Autologic libraries are located should be referenced by the MGC_SYNLIB environment variable: