In the Cortex-A72 processor, the CTI operates in the PCLKDBG domain and it synchronizes the trigger inputs and outputs to PCLKDBG.
Handshaking is required for all trigger outputs. Because the simplified CTM is implemented in the same clock domain, synchronization and handshaking is not required for channel interface. In addition, APB synchronization is not required. Trigger inputs are not masked by internal NIDEN. Trigger outputs are not masked by internal DBGEN.