How do I instantiate an ADSU8 in ISE7.1i?

Hi,

I am trying to use the ADSU8 library element in ISE7.1i. The libraries guide says its inferred by HDL (Verilog in my case) but does not give an example.

I can create it with the schematic editor but not with Verilog.

I have tried to express the unit in a number of different ways. Rather than embarrass myself by posting bad code, I'll just ask the question - is there a trick to it?

Thanks, Paul.