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:
http://www.xilinx.com/support/download/index.htm
| Answer Number | Answer Title | Version Found | Version Resolved |
|---|---|---|---|
| 33381 | ISE Design Suite 11 - ISE Simulator (ISim) Known Issues | N/A | N/A |