AR# 1521: syn2xnf : ERROR 220: Can't open file '__ffgen__.xnf'
AR# 1521
syn2xnf : ERROR 220: Can't open file '__ffgen__.xnf'
説明
While running syn2xnf or xmake on a Synopsys generated design the following error may occur :
syn2xnf : ERROR 220: Can't open file '__ffgen__.xnf'
Upon further investigation into the .sxnf file you may find lines similar to :
SYM,MY_reg<0>,__FFGEN__,LIBVER=2.0.0
ソリューション
1
One possible cause of this is an incorrect .synopsys_dc.setup file.
1. Verify you have the proper search paths in the the proper order in the file. The search path order should be the project directory, followed by the Xilinx library directory followed by the Synopsys library directory.
2. Verify you have the correct libraries by comparing with the output of synlibs.
synlibs (-dc or -fc) <part> where -dc is for Design Compiler and -fc is for FPGA Compiler
Example : synlibs -fc 4005e-3
3. Verify you have all the necessary environment parameters by comparing with one of the example setup files located in : $DS410/examples/synopsys directory.
2
A second possible cause of this error is descibing a register in the HDL code which the targeting architecture can not support.
For example, if you describe a flip-flop that has both an asynchronous set and an asynchronous reset in an XC4000 design, Synopsys will create an __ffgen__ because there is no corresponding primative to infer. The XC4000 family registers have an asynchronous set or reset but not both at the same time on the same register.
If this is the case, the HDL code needs to be modified to accomodate the targeting architecture.