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Status Bar

The Status Bar displays error and trace messages whenever the trace functionality is active. 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 area:

  • 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, 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 can cause this message. See Note below.
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. Adjust the prescaler values or the clock settings for the trace port or debug port.
No Synchronization Synchronization packets are not received from the target. The trace hardware is either not connected or configured improperly. Check the device data sheet. Additional help can be found in Configure Cortex-M Devices for Tracing.
Data Stream Error Errors are detected in the Trace Data Stream.
Data Overflow The Trace Port was too busy, and not all trace packets could be transmitted. This happens when too many trace data are captured. The Instruction Trace Window shows when the overflow occurred.
Running ... The target and tracing are both running without errors.
<no message> The target stopped without errors.


  • Applications that change the Core Clock in the main() program may throw the Communication Error message, since trace data are captured incorrectly. This error message disappears once the Core Clock has been adjusted to the system settings.
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