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Streaming Trace

To analyze the program behavior on target systems, code debugging can be used, but with increasingly complicated systems it is not always possible to use a stop-and-go mechanism to detect program glitches. There is a need to gather data in real-time while the device is running at full speed.

Cortex-M processor-based devices use CoreSight Macrocells for real-time tracing like the Embedded Trace Macrocell, Instrumentation Trace Macrocell, and Data Watchpoint and Trace Unit. Real-time trace data are pushed to the host's hard disk via the debugger adapter, from where µVision picks up the data to show them in µVision Windows.

Streaming trace (real-time trace) when combined with ULINKpro, offers many advantages:

  • Trace data are delivered in real-time to the host computer.
  • The data amount is limited by the host computer only (hard disk).
  • Tracing is possible for minutes, hours, or longer.
  • Modern computers can handle traced data instantly.

The delivered trace data are:

  • Program counter values.
  • Data reads and writes.
  • Event counters.
  • Exception entry and returns.
  • Timestamps and CPU cycles used.
  • Executed instructions.

Streaming data are output on a 4-bit dedicated trace bus and are captured by special debugger adapters, such as ULINKpro.


  • Not all Cortex-M processor-based devices have an Embedded Trace Macrocell.
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