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AR# 31626

10.1 XST - "WARNING:Xst - MapTools/FillSupport: no edge found"


When synthesizing a project in XST, the following error occurs:

"WARNING:Xst - MapTools/FillSupport: no edge found

INTERNAL_ERROR:Xst:cmain.c:3378: - To resolve this error, please consult the Answers Database and other online resources at http://support.xilinx.com"

How do I resolve this issue?


To work around this issue, consider trying to disable the "Equivalent Register Removal" option in XST. See the XST User Guide for more information on applying this option:


If this issue occurs for an EDK MPMC core, the source code can be modified to disable the option in Verilog:

1. Copy the mpmc pcore from the "$XILINX_EDK/hw/XilinxProcessorIPLib/pcores" directory to the project pcores directory.

2. In the "hdl/verilog" directory, make mpmc.v writeable, and add the following near the top of the file, directly above the line: "module mpmc"

(* equivalent_register_removal = "no" *)

3. Close and reopen XPS and rebuild the netlist.

AR# 31626
Date Created 09/08/2008
Last Updated 12/15/2012
Status Active
Type General Article