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µVISION DEBUGGER: µVISION does not detect Mbed DAPLink

Information in this knowledgebase article applies to:

  • MDK version 5.28 and earlier
  • DAPLink versions which are based on CMSIS-DAP V2


µVision version 5.28 or before does not detect an Mbed DAPLink debug adapter which is based on CMSIS-DAP V2.


An Mbed DAPLink device is a USB composite device which consists of several USB classes (MSC, CDC, HID, WinUSB). Since CMSIS-DAP V2, a WinUSB bulk transfer is used instead of USB-HID. The µVision CMSIS-DAP debug driver always used the first interface (0) of a USB composite device to communicate. However, new DAPLink releases have the MSC on interface 0 and WinUSB on a higher interface number.


Download the attached ZIP file and extract the CMSIS-DAP debug driver file (CMSIS_DAP.dll V0.2.14.1) into the MDK installation folder \ARM\BIN. If the default installation path was used, this is the folder C:\Keil_v5\ARM\BIN

This patch fixes the issues described as 'current limitation #1' for this GitHub commit.


This will be fixed in MDK version 5.29 and later.



Request the files attached to this knowledgebase article.

Last Reviewed: Wednesday, September 25, 2019

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