ISE Xst:2183 warning syntesizing

VHDL / Verilog Discussion
1

I am receiving the following warning while trying to synthesize my design:

WARNING:Xst:2183 - Unit XLXI_136/XLXI_12: the following tristate(s) are NOT replaced by logic (Please refer to Answer Record 20048 for more information): ok2, ok2, ok2, ok2, ok2, ok2, ok2, ok2, ok2, ok2, ok2, ok2, ok2, ok2, ok2, ok2, ok2.

Any information on why this warning is popping up and how I can clear it up??

Thanks.

2

This generally occurs because the logic in our modules describes tristate features which aren’t available in the Spartan-3. XST converts these, instead, to multiplexers which serve the same purpose.

Because of the variable size of the bus used to service endpoints, it just makes things easier to describe a tristate bus and allow XST to do the translation.

These warnings may safely be ignored.

3

I figured that it wasn’t causing any problems since everything seemed to work still but I was just curious. There isn’t any way to get rid of the warning though is there??

Thanks for the response.

4

In many C/C++ compilers, one can turn off compiler warnings with certain “#pragma” directives. I’m not aware of anything similar for XST and its ilk.