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AR# 33068

11 EDK - Why does SDK hang while it is communicating with the FPGA?


Why does SDK hang while it is communicating with the FPGA during a bitstream download, run, debug, or profile?


The Xilinx Microprocessor Debugger (XMD) is a key part of SDK's communication with the FPGA. XMD runs on top of the Xilinx distribution of bash called "xbash". Some of SDK's communication problems are linked to a problem found in xbash. A tactical patch has been created to address this problem which occurs only on Windows.

To install the patch:

1. Make a backup of "C:\Xilinx\11.1\EDK\bin\nt\unwrapped\xbash.exe".

2. Download the file at:


3. Extract the contents of the file to "C:\Xilinx\11.1\EDK".

The patch is intended for both 11.1 and 11.2. This fix will become mainstream in the 11.3 release of the software.

NOTE: Installing this patch will disable XMD's auto completion feature. To re-enable auto completion while using XMD outside of SDK, set the environment variable RUNNING_EDK_XBASH to 1. The environment variable must be turned off when using SDK.

This problem has been fixed in EDK 11.3, available at:


AR# 33068
Date Created 07/08/2009
Last Updated 12/15/2012
Status Active
Type General Article