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AR# 6662

9.1i NGDBuild/Constraints - An instantiated TDO pad conflicts with a UCF (User Constraints File) constraint, causing "ERROR:baste:263"


When I place a location constraint on the TDO pin, either as a schematic attribute or in a .ucf file, the following errors occur:

"ERROR:OldMap:69 - LOC constraint "P76" on TDO symbol "$I1" (pad signal=TDOOUT) not supported."

"ERROR:baste:16 - LOC constraint "P76" on TDO symbol "$I1" (pad signal=TDOOUT) not supported."

When I instantiate a TDO BUF in VHDL (FPGA Express Flow) and the TDO pin is also locked in the .ucf file, the following fatal error occurs:

"ERROR:baste:263 - The LOC constraint "P76" (a TESTDATA location) is not valid for symbol "M2A<4>.PAD" (pad signal=M2A<4>), which is being mapped to the following site types: CLKIOB IOB"


To avoid the error, do not put a LOC constraint on the TDO pin. This pin is already locked down to a specific location on the device.

For more information, see (Xilinx Answer 2449), (Xilinx Answer 3416), and (Xilinx Answer 3753).

AR# 6662
Date Created 08/21/2007
Last Updated 01/18/2010
Status Archive
Type General Article