When I attempt to run a design with VHDL top level, and a submodule in the form of NGC which has constraints mentioned in ncf, I receive an error similar to the following:
"ERROR:NgdBuild:755 - "../../../.ncf" Line 27: Could not find net(s) 'fpga_0_RS232_Uart_RX_pin' in the design. To suppress this error specify the correct net name or remove the constraint. The 'Allow Unmatched LOC Constraints' ISE property can also be set ( -aul switch for command line users)."
However, when I check the UCF the constraint does exist.
How can I prevent this error?
The error occurs because of the case sensitivity of the NCF along with NGC; ncf/ngc support is case sensitive, while ncf/edf and ucf support is case insensitive
To work around this problem, perform one of the following:
- Edit the NCF with the same case as that in VHDL.
- Copy the constraints from NCF to UCF.