1.5.2.3 Embedded Trace Macrocell

The ETM block is a high speed, low power-consumption debugging tool that provides instruction trace only, and which feeds output to the TPIU. The ETM has a FIFO queue of 24 bytes, and ETM outputs 8 bits of data at a time at the core clock speed. This output is compatible with the AMBA trace bus (ATB). The ETM trace is supported by tools like Keil Trace, IAR Trace, Greenhills software trace, and others. The ETM provides the following features:

  • Tracing of 16-bit and 32-bit thumb instructions
  • Four EmbeddedICE watchpoint inputs
  • A Trace Start/Stop block with EmbeddedICE inputs
  • Two external inputs
  • Global time-stamping
Important: Timing model for Fabric to Embedded Trace Macrocell has been updated with additional time delay. This changes the timing arcs of nets between Fabric to Embedded Trace Macrocell. To meet timing accuracy, open all Libero v11.7 SP3 designs and re-run Timing Analysis. If you get new timing violations, do the following:
  1. Re-run place-and-route.
  2. Re-run place-and-route with high effort.
  3. Run place-and-route with multi-pass.
  4. Adjust timing constraints or use chip planner to floorplan the affected interfaces.

    For more information about the updated timing arcs, see PCN 17005A.