SPRUI30H November 2015 – May 2024 DRA745 , DRA746 , DRA750 , DRA756
The device takes advantage of the system trace infrastructure to provide visibility to the user about the major power-management events. This is supported through a PMI module (PM profiler) instantiated in the PRM module. The PRM state changes are handled as generic events and encapsulated in STP hardware messages and exported through the CT_STM module. The nature of the PM events does not require accurate timestamping and thus, timestamping is handled at CT_STM or trace receiver level.
The PM events are organized by class. Any PM state change from a specific class refreshes the entire instrumentation frame associated with that class. The STP message structure includes a PM event-ID indicating the class of the PM events.
The PM event classes supported are:
The PMI has a unique hardware master-ID assigned to it (see Section 33.10.10, Master-ID Encoding).
The PMI supports the possibility to report on activity in different event classes in the same sampling window. The user can size the capture sampling window.
Software events from the PM routines instrumentation can be interleaved with the PM hardware events. The user can take advantage of that feature to understand latencies for a specific power-management scenario or strategy.
The PM module implements an instrumentation port that directly interfaces with the debug subsystem (used to export PM events to CT_STM).