Xilinx Answer #4240 : A1.4/F1.4 MAP - Connection to TDO pad lost when signal is merged (WARNING::x4kdr:23 - Blockcheck: The comp (mapped physical logic cell) "DIA_RSCI" does not have any pins that are being used)

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A1.4/F1.4 MAP - Connection to TDO pad lost when signal is merged (WARNING::x4kdr:23 - Blockcheck: The comp (mapped physical logic cell) "DIA_RSCI" does not have any pins that are being used)

Record #4240
Product Family: Software

Product Line: FPGA Implementation

Product Part: map

Product Version: 1.4.

Problem Title:

A1.4/F1.4 MAP - Connection to TDO pad lost when signal is merged (WARNING::x4kdr:23 - Blockcheck: The comp (mapped physical logic cell) "DIA_RSCI" does not have any pins that are being
used)

Problem Description:
Urgency : HOT

General Description:
Map loses the connection to a TDO pad when the net driving the TDO pad is
merged into another net. The circuit has the following configuration:

DFF->INV->INV->OBUF->TDO

The resulting circuit included a configured TDO component
with no net attached, which leads to the following DRC warning.
DRC gives the following warning:

WARNING:x4kdr:23 - Blockcheck: The comp (mapped physical logic cell) "DIA_RSCI"
does not have any pins that are being used.

Solution 1:

This problem can be avoided by putting a KEEP (no merge) property
on the net driving the OBUF:

NET netname KEEP;

End of Record #4240 - Last Modified: 08/24/98 12:15

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