The Cortex-A53 processor has a single external cross trigger channel interface. This external interface is connected to the CoreSight Cross Trigger Interface (CTI) interface corresponding to each core through a Cross Trigger Matrix (CTM). A number of Embedded Cross Trigger (ECT) trigger inputs and trigger outputs are connected between debug components in the Cortex-A53 processor and CoreSight CTI blocks.
The CTI enables the debug logic, ETM trace unit, and PMU, to interact with each other and with other CoreSight components. This is called cross triggering. For example, you configure the CTI to generate an interrupt when the ETM trace unit trigger event occurs.
Figure 14.1 shows the debug system components and the available trigger inputs and trigger outputs.