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AR# 11523

ModelSim (MXE, SE, PE) - "Fatal: ERROR: SDF files require Xilinx primitive library" (VHDL, Verilog)


General Description:

When I run timing simulation, the following error occurs when I enter the VSIM command:

"Fatal: ERROR: SDF files require a Xilinx primitive library."


This error can occur for several reasons:

- Using ModelSim XE with a user-compiled SimPrim Library

- Using ModelSim XE/PE/SE and applying the SDF to an RTL (pre-synthesis) design

Using ModelSim XE with a User-compiled SimPrim Library

All of the Xilinx libraries are pre-compiled and installed with MXE. It is required that the pre-compiled libraries are used with MXE. If you have manually compiled the simulation libraries, you must re-install MXE or download the latest pre-compiled libraries from the Web and install them.

For information on obtaining the updated pre-compiled libraries, see (Xilinx Answer 10616).

Using ModelSim XE/PE/SE and Applying the SDF to an RTL (pre-synthesis) Design

The SDF file contains delay information for all the gates and wires in the netlist. However, for the simulator to account for those delays, the gate-level (structural/back-annotated) netlist that is written by the Xilinx netlister tools (NGD2VHDL/NGD2VER) must be used. If the SDF is used with an RTL design file, this error will occur.

Usually, this error is due to the Xilinx netlister tools renaming the top-level entity name when the "-te" option is used ("-tm" option for Verilog). (By default, the Xilinx netlister tools retain the top-level entity name as it appeared in the RTL design.)

There are two resolutions to this problem:

- Check the top-level entity/module name in the output VHDL/Verilog file generated by Xilinx, and change the instantiation in the test bench to match it.

- Ensure that the "-te" option ("-tm" for Verilog) is not used.

AR# 11523
Date Created 08/29/2007
Last Updated 12/15/2012
Status Active
Type General Article