When I generate my ICON Core through CORE Generator, I see the following errors in NGDBuild:
"ERROR:NgdBuild:756 - "../cs/icon.ncf" Line 1: Could not find net(s)
'U0/U_ICON/iDRCK' in the design. To suppress this error specify the correct
net name or remove the constraint."
This error occurs when the a BUFG is not included on the JTAG clock line in the ICON Core. To work around this, enable inserting the BUFG on the ICON by unchecking the "Disable JTAG Clock BUFG Insertion" checkbox.
This issue will be resolved in ChipScope Pro 10.1 Service Pack 2.