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Trace Status

The µVision Status Bar displays trace status messages whenever tracing has been enabled. Additional information is available in the general description of the Status Bar for CPUs that have enabled TrustZone for Armv8-M.

Trace Status Bar

The trace status:

  • Displays progress and error messages when the target processor is running.
  • Refreshes the Running... message every 3 seconds during error-free operations.
  • Is blank, when tracing is stopped without an error.
  • Displays the error message in red when the target stopped with an error.
  • Keeps the error message displayed until tracing is restarted.

Trace Status Messages

Message Description
Communication Error An invalid communication has been detected. Incorrect clock settings or hardware problems cause this message. Applications that change the Core Clock in the main() program may throw this message when data are captured incorrectly. This error message disappears once the Core Clock has been adjusted to the system settings.
HW Buffer Overrun The USB port cannot accept data at the speed the adapter is sending them. Turn off trace events you do not need, or skip PC Sampling.
SW Buffer Overrun Internal SW buffer overrun on the PC (this should never happen).
No Synchronization There are no synchronization packets received from the target. This indicates that the trace hardware is either not connected or improperly configured.
Data Stream Error Errors are detected in the Trace Data Stream.
Data Overflow This indicates that Trace packets couldn't be transmitted because the Trace Port was too busy. The Trace Records dialog shows when the overflow occurred. This happens when too much Trace data is being captured.
Running ... The target system itself and tracing operations are running without errors.
<no message> The target stopped without throwing an error.


To use Trace in your application before changing the clock setting, configure Trace with the startup (default) clock value then reconfigure Trace clock later (via dialog or by using the CORE_CLK VTreg directly from the command window or some custom load script).

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