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AR# 33431

ISE Simulator (ISim) - Output of bi-directional signals always appear as an unknown force ('X')


When I simulate a design that has bi-directional ports coming out of an OBUFTDS bi-directional primitive, the output is always an unknown force ('X'). Inputs to the OBUFTDS appear valid.

How can I resolve this issue?


This is a known issue. It has been fixed in ISE Design Suite 11 Update 3 (11.3). Please download and install the latest ISE Design Suite update from the Download Center at:


Linked Answer Records

Associated Answer Records

Answer Number Answer Title Version Found Version Resolved
33381 ISE Design Suite 11 - ISE Simulator (ISim) Known Issues N/A N/A
AR# 33431
Date Created 09/08/2009
Last Updated 12/15/2012
Status Active
Type General Article