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ARM: Can't connect to TLE986x with ULINK2

Information in this knowledgebase article applies to:

  • ULINK2
  • Infineon TLE986x


I try to connect with the debugger to an Infineon TLE986x device using an ULINK2. But this does not work. I always get a "SWD Communication Error". What is the problem?


The device has Serial Wire (SW) debug only. But this is not selected by default. So just trying to connect in SW mode fails.
Further, the device can only be connected, while the internal bootloader is still executing. Once the user program runs, it is too late to establish a debug connection.


To switch the debug interface to SW mode, make sure the SWJ switch is checked. With that the debugger executes a special sequence, that switches to the SW interface, so that later the debugger can connect via SW.
To get the debugger to connect while the internal bootloader runs, select "with Pre-Reset" as the connect option in the ULINK Debug Settings.
The following image shows the recommended settings: TLE986x ULINK Settings

As the TLE986x operates with 5V it is also recommended, to set the jumper "VCC" of the ULINK2 to the "ARM" position.


Last Reviewed: Thursday, July 20, 2017

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