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µVISION DEBUGGER: CMSIS-DAP debug adapter has no Serial No.

Information in this knowledgebase article applies to:

  • MDK-ARM v5.15 and older versions
  • µVision Debugger


I use several debug adapters with a CMSIS-DAP interface in µVision. But one of them has no Serial No. shown in the Debug Settings, as illustrated in this screenshot:

I can perform debugging without any issue by using any other debug adapter listed in the CMSIS-DAP - JTAG/SW Adapter drop-down list except for the one without the Serial No. If I try to start the debug session using that debug adapter, it returns the error shown below:


In MDK-ARM v5.15 and all older versions, if there are multiple CMSIS-DAP debug adapters available, µVision uses the Serial No. of the debug adapters to distinguish between them.

If, for some reason, µVision does not recognize the Serial No. of a CMSIS-DAP debug adapter, it will not select or use it.


The selection mechanism of multiple CMSIS-DAP debug adapters has been improved in MDK-ARM v5.16 and newer versions. MDK-ARM v5.16, uses both the Serial No. and the name of adapters to distinguish different CMSIS-DAP debug adapters.

You can install MDK-ARM v5.16 or newer versions to solve this issue, or by downloading and replacing two DLL files from the attachment into your MDK-ARM installation folder.



Request the files attached to this knowledgebase article.

Last Reviewed: Thursday, September 22, 2016

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