Answers Database

SYN2XNF: Use of -s option causes creation of EXT records, XNFPREP Error 3527


Record #453

Product Family:  Software

Product Line:  Synopsys

Problem Title:
SYN2XNF: Use of -s option causes creation of EXT records, XNFPREP Error
3527



Problem Description:
Syn2xnf -s creates external "EXT" records causing XNFPREP to fail. Syn2xnf -s (s
ub)
is supposed to create a hierarchical block (without any IOs) but it still create
s EXT records
for .sxnf file written by Synopsys FPGA Compiler. The XNF format .xnf and .xff f
iles have
EXT records. This will cause XNFPREP to give errors related to pads connected to
 internal
nodes.



Solution 1:


The cause of the problem is that SYN2XNF -s only works on EDIF format file (whic
h implies Design Compiler). If the design is written out as a .sxnf file, there
will still be EXT records written into it.
The only solution is to  manually remove the EXT records at the end of the .sxnf

files generated by Synopsys; or write out an edif format file instead.





End of Record #453