7.9.1. EmbeddedICE watchpoint comparator input behavior

Providing control of the behavior of the EmbeddedICE inputs, and specifying different default behavior of these inputs in different contexts, makes these signals more useful for controlling tracing.

For example, when used for the TraceEnable event, the normal requirement is that the controlling input is held between comparisons, to ensure that the TraceEnable state is held through a range of addresses:

In contrast, when an EmbeddedICE input is used as an input to the trace start/stop block, it is preferable for the input to be pulsed for a single cycle. This avoids the possibility, for example, that a stop signal might be missed because a start signal from an EmbeddedICE input is being maintained.

To take account of these different requirements, the ETMEIBCR enables a debugger to program the behavior of each EmbeddedICE watchpoint input, as pulsed or latched, depending on the current use of each input. For more information see EmbeddedICE Behavior Control Register, ETMEIBCR, ETMv3.4 and later.

If the ETMEIBCR is not implemented then the behavior of the EmbeddedICE watchpoint inputs must differ for different resources, as defined in Default behavior of EmbeddedICE watchpoint inputs.

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