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AR# 9651

3.x FPGA Express, 3.1i NGDBuild - "ERROR:NgdBuild:455 - logical net 'xxxx' has multiple drivers"


Keywords: FPGA, Express, BUFG, IOREG, IPAD, XC, XC4000, 4000, 4k

Urgency: Standard

General Description:
In FPGA Express 3.4 (XC4000 and Spartan architectures only), the option "Use I/O Reg" under the "Ports" tab is TRUE by default. When I change from TRUE to FALSE, FPGA Express makes improper IPAD/Port connections to the inferred BUFG. This causes in the following error in NGDBuild:

"ERROR:NgdBuild:455 - logical net 'xxxx' has multiple drivers."


To avoid this error, instantiate all the BUFGs that you will require.

Please also see (Xilinx Answer 9649) for more information.
AR# 9651
Date Created 07/06/2000
Last Updated 08/11/2003
Status Archive
Type General Article