12.2.2. APB interface

The ITM has an AMBA 3 APB interface that restricts accesses to pure 32-bit transfers. This interface is used both to stimulate trace and to control the ITM. To reduce the data overhead when only writing low values to stimulus registers, the ITM uses leading zero compression on data values.

Stalled transfers are not permitted to registers between 0x000 and 0xDFC. This ensures that any writes to present or future stimulus registers do not decrease system performance.

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