ULINK: Trace port selection using ULINKpro
Information in this knowledgebase article applies to:
- Keil MDK
- ULINKpro, ULINKpro-D Debug Adapter
I am using ULINKpro and enabled the Trace in Options for Target
- Debug - Settings - Trace.
Serial Wire Output - UART/NRZ is selected as Trace port, as
shown in the screenshot.
However, when I try starting a Debug Session, the error
Selected Trace Port is not supported is shown.
Which Trace Port is supported by ULINKpro?
- ETM Instruction Trace
After enabling ETM trace, in the Trace Port droplist, Sync
Trace Port with 4-bit Data needs to be selected. Sync
Trace Port with 1-bit Data or Sync Trace Port with 2-bit
Data mode cannot provide enough data bandwidth for ETM trace
data, since fewer trace port pins are used in these cases.
Note, ETM trace is supported by ULINKpro, but is not supported
by ULINK2 or ULINKplus.
- ITM/DWT Trace
When using ULINKpro, Serial Wire Output - Manchester is
typically selected, which provides better tolerance of difference
between trace clock setting and system core clock, which results
in better-synchronized trace data.
Sync Trace Port with x-bit Data modes can also be
selected when using ULINKpro, if 4/2/1 pins trace port is
available and properly configured.
Note, Serial Wire Output - UART/NRZ mode is not
supported by ULINKpro. That's the reason why the error above
When using ULINK2, the only supported option Serial Wire
Output - UART/NRZ is selected by default. This mode requires
setting the trace clock identical to the system core clock, in
order to get synchronized trace data.
Note that Sync Trace Port with x-bit Data and Serial
Wire Output - Manchester modes are not supported by
Last Reviewed: Tuesday, November 3, 2020