12.1. About the Instrumentation Trace Macrocell

The CoreSight ITM block is a software application driven trace source. Supporting code generates SoftWare Instrumentation Trace (SWIT). In addition, the block provides a coarse-grained timestamp functionality. The main uses for this block are to:

Figure 12.1 shows a block diagram of the ITM.

Figure 12.1. ITM block diagram

The ITM contains the following sub-blocks:


Generates timestamp packet.

Sync control

ITM synchronizer.


Arbitrates between synchronous, timestamp, and SWIT packet.


ATB First In First Out (FIFO).


ATB registered emitter.

Data is written to the stimulus registers using the APB interface. See Stimulus registers. This data is then transmitted on the ATB interface as SWIT packets as described in SWIT packet.

The operation of the ITM is described in more detail in:

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