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AR# 22210

ChipScope Pro - When I try to connect to the JTAG cable, the Analyzer GUI will 'hang'


Keywords: analyzer, Parallel IV, USB, Scan, TCP/IP, 50001

I am unable to connect to my cable in ChipScope. However, iMPACT is able to connect to the cable. I see the following messages in my cs_analyzer.log file:

INFO:Opened socket connection: localhost 50001 localhost/
ERROR:Client communication thread failed: java.nio.BufferUnderflowException
at java.nio.Buffer.nextGetIndex(Unknown Source)
at java.nio.HeapByteBuffer.getInt(Unknown Source)
at com.xilinx.chipscope.analyzer.csert.CseClient.socketReadPacket(CseClient.java:842)
at com.xilinx.chipscope.analyzer.csert.CseClient.readUntilRequestedResponse(CseClient.java:781)
at com.xilinx.chipscope.analyzer.csert.CseClient.sendOneCommand(CseClient.java:541)
at com.xilinx.chipscope.analyzer.csert.CseClient.sendCommand(CseClient.java:486)
at com.xilinx.chipscope.analyzer.csert.Cse.jtagSessionCreate(Cse.java:1390)
at com.xilinx.chipscope.analyzer.devcomm.OpenCableAction.runCseThread(OpenCableAction.java:201)
at com.xilinx.chipscope.analyzer.csert.CseClient.handleQueues(CseClient.java:1248)
at com.xilinx.chipscope.analyzer.csert.CseClient.access$000(CseClient.java:73)
at com.xilinx.chipscope.analyzer.csert.CseClient$1.run(CseClient.java:1191)
ERROR:Internal Error - runCseThread method() failedjava.lang.NullPointerException

What is the problem? How can I work around this issue?


ChipScope communicates with the cable via a client/server TCP/IP interface. By default, this communication is on TCP port 50001. Many antivirus and firewall programs prevent this type of communication. You must uninstall or disable the antivirus or security software and allow TCP/IP communication in order to use ChipScope.

The following software has been known to cause this problem (uninstalling or disabling the software resolved the issue):

- Norton Internet Security
- Panda Software Titanium 2005 antivirus
- ZoneAlarm software version 5.1
- Spysweeper from Webroot Software Inc, CommAgent.exe

Another solution to this problem is to attempt communication on another TCP/IP port. You can do this by launching the server manually (follow the "Analyzer Server Interface" section of the ChipScope Pro User's Guide).
AR# 22210
Date Created 09/04/2007
Last Updated 07/30/2009
Status Active
Type General Article