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AR# 19077

6.2 ChipScope Pro - "ERROR:NgdBuild:756 - Line 2 in 'icon.ncf': Could not find net(s) 'iupdate_out' in the design"

Description

Keywords: ChipScope, 6.1, 6.2, ERROR, NGDBuild, 756, icon, ncf, find, net, iupdate_out, ishift_out, Enable, unused, boundary, scan, port, Boundary, Scan, Boundary Scan

Urgency: Standard

General Description:
When using the ChipScope Pro Core Generator flow to obtain an ICON core with "Enable unused boundary scan port" for instantiation in a design, NGDBuild errors out when trying to implement the design with the core.

"ERROR:NgdBuild:756 - Line 2 in 'icon.ncf': Could not find net(s) 'iupdate_out' in the design. To suppress this error specify the correct net name or remove the constraint."
"ERROR:NgdBuild:756 - Line 3 in 'icon.ncf': Could not find net(s) 'ishift_out' in the design. To suppress this error specify the correct net name or remove the constraint."

Solution

This appears to be due to two incorrect "ncf" timing constraints:

NET "iupdate_out" TNM_NET = U_CLK ; (should be update_out)
NET "ishift_out" TIG ; (should be shift_out).

To work around this, manually modify the ".ncf" file with the correct NET names:

1. Run ChipScope Generator, and generate the ICON core with "Enable unused boundary scan port".
2. Open the file "icon.ncf" present in the ouput folder.
3. Replace iupdate_out by update_out and ishift_out by shift_out :
NET "update_out" TNM_NET = U_CLK ;
NET "shift_out" TIG ;
4. Save the file.

This problem has been fixed in the latest 6.2i Service Pack available at:
http://support.xilinx.com/xlnx/xil_sw_updates_home.jsp
The first service pack containing the fix is 6.2i Service Pack 2.

AR# 19077
Date Created 09/03/2007
Last Updated 06/20/2008
Status Archive
Type General Article