15.8.5 Supporting multiple trace capture devices

A DTSL configuration can contain several trace capture devices. The following are some possible reasons for this:
In some cases, there can only be one active trace capture device. In this case, you can choose whether to use the DSTREAM or the ETB. In other cases, there can be several trace capture devices active at the same time. This is common when the platform contains multiple clusters of cores, each of which outputs trace to its own CoreSight ETB.
Figure 15-17 Example of Multiple Trace Capture Devices
Example of Multiple Trace Capture Devices

To allow trace clients to receive trace data from a trace source, the DTSL configuration can be told about the association between a trace source and one or more trace capture devices. In the figure, for example, the trace source named PTM_2 is associated with the trace capture device named ETB_1. If a client wants to display the trace data for PTM_2, it can ask DTSL which trace capture devices are associated with that trace source, and direct its trace read requests to the correct trace capture device.

Note

It is possible for a trace source to be associated with multiple trace capture devices, such as an internal ETB and an external DSTREAM. In such cases, you might need to provide more information to the client about which trace capture device to use when reading trace data.
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