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AR# 17856

6.1i NGDBuild LogiCORE PCI - "ERROR:NGDBUILD:752 - Line ### in UCF. Could not find instance(s) 'PCI_CORE/PCI_LC/... in the design..."


General Description:

The following type of error occurs in NGDBuild when I run the command line script to implement a Xilinx PCI Core:

"ERROR:NgdBuild:752 - Line 521 in '../../src/ucf/v300bg432_64_66.ucf': Could not find instance(s) PCI_CORE/PCI_LC/PCI-PAR/APERR_1' in the design. To suppress this error, specify the correct instance name or remove the constraint. The 'Ignore I\O constraints on Invalid Object Names' property can also be set ( -aul switch for command line users )"

The instance path in the error may vary.


These errors are generated when NGDBuild cannot find the netlist for the PCI core. The netlist for the PCI core is called "pci_lc_i.ngo".

This file is located in the following directory:


The XPCI directory must be sourced by the NGDBuild command line.

Command Line Example:

ngdbuild -sd ../../src/xpci

-sd ../synthesis

-uc ../../src/ucf/v300pq240_32_33.ucf


The best implementation method is described in the implementation guide, which is available in the <LOGICORE_PCI_INSTALL_DIR>/docs directory.

AR# 17856
Date Created 09/03/2007
Last Updated 12/15/2012
Status Active
Type General Article