Answers Database

SYNOPSYS FPGA COMPILER: Problems reading an XNF file back into Synopsys.


Record #515

Product Family:  Software

Product Line:  Synopsys

Problem Title:
SYNOPSYS FPGA COMPILER: Problems reading an XNF file back into Synopsys.


Problem Description:
Synopsys issues errors when reading in a post place-and-route XNF file. It issue
s one or
more messages such as:

Error: File 'count8/count8.xnf', Line 54 at or near 'N171': Cannot match this DF
F to a
set of pins.  Is it specified correctly?. (XNFI-1)


Solution 1:

This occurs when you try to read in an XNF file that has been translated from th
e placed
and routed lca file by LCA2XNF. An XNF file generated by LCA2XNF cannot be read
in by Synopsys.

In order to read in a back-annotated XNF in Synopsys, the following
steps must be followed after place and route:

1) LCA2XNF design

2) XNF2VSS design
   (This will generate an .vxnf file and attach SCHNM attributes,
    which are needed for the Synopsys XNF reader, in the XNF file.)

3) rename the .vxnf to .xnf

4) Read the .xnf output by XNF2VSS into Synopsys.







End of Record #515