Answers Database

LCA2XNF 5.2.1: Outputs an Inaccurate .xnf file


Record #2074

Product Family:  Software

Product Line:  FPGA Core

Problem Title:
LCA2XNF 5.2.1: Outputs an Inaccurate .xnf file


Problem Description:
Keywords: LCA2XNF, missing, D pin, 5-input gate, invert

Urgency: Standard

General Description:
--For xc4000/xc4000E under some particular routing conditions
LCA2XNF 5.2.1 might:

*Loose the D pin on a RAM
*Loose the D pin or SR pin on a CLB flipflop

--For the 5200 family:

*The .xnf file might have a 5-input gates, where it should
 generate a gates with inputs of up to 4.
*Also it might invert the I-pin to an IBUF, where it really
 should have inverted the o-pin of the IBUF instead.
 After translating a .lca file to a .xnf file no errors occur.
 But with closer inspection of the .xnf file, one can see that
 some flipflop's are missing a D inputs.




Solution 1:

Get a patched version of LCA2XNF from the xilinx ftp site.
(Xilinx File ftp://ftp.xilinx.com/pub/swhelp/xact-pc/lca2xnf.zip)
(Xilinx File ftp://ftp.xilinx.com/pub/swhelp/xact-workstation/lca2xnf.sun4.tar.Z
)
(Xilinx File ftp://ftp.xilinx.com/pub/swhelp/xact-workstation/lca2xnf.hppa.tar.Z
)

Choose the patch according to your
Operating system.



End of Record #2074