SPRUI30H November 2015 – May 2024 DRA745 , DRA746 , DRA750 , DRA756
The debug subsystem implements three exclusive trace sinks:
Two MPU trace streams are supported, one per MPU core. The two MPU cores program traces are exported to the PD_EMU domain (through asynchronous bridges) and then interleaved by the CS_TF_MPU.
A concurrent software instrumentation flow from the local CS_STM component (STP 2.0) can also be interleaved with the MPU program traces.
Two ATB_FIFO modules (ATB_FIFO_MPU_C0 and ATB_FIFO_MPU_C1) are implemented in the trace path between the Cortex-A15 CPUs and the CS_TF_MPU module. The ATB_FIFO allows concurrent trace capture and export. It provides buffering in the trace export path and therefore allows absorbing peaks of trace data. The depth of the ATB_FIFOs is 16 entries.
The CS_TF_MPU sends the MPU trace (or CS_STM software instrumentation) to a trace funnel in the debug subsystem (CS_TF_DEBUGSS) through a single ATB interface. The CS_TF_DEBUGSS redirects the MPU trace to the three exclusive trace sinks.
It is strongly recommended to disable trace sinks not in use when generating trace to an in-use trace sink to eliminate undesirable throughput throttling effects.
Besides the ATB_FIFOs, the MPU subsystem also instantiates an ATB_FIFO statistics gathering unit (ATB_FIFO_SGU) which provides silicon and presilicon characterization information of ATB_FIFO. The FIFO_LEVEL_OUT output of ATB_FIFO, which gives visibility of the number of used entries, is used for the statistics gathering. ATB_FIFO may be full under the following conditions:
The following statistics are gathered per ATB_FIFO: