SWCU191 February 2022 CC1311P3 , CC1311R3 , CC2651P3 , CC2651R3 , CC2651R3SIPA
The COMPB event can trigger System CPU wakeup in two ways:
Direct wakeup infers minimum wake-up latency. It is however not possible to clear the COMPB event in AON_EVENT as is comes directly from the comparator.
Indirect wakeup infers latency that scales with the SCE clock rate, which depends on the AUX operational mode, as described in Section 20.2.1. The latency is given by a two-stage synchronizer and event flag capture and bounded upwards by three SCE clock periods. The System CPU can clear the event flag on wake up, and hence return to sleep while the COMPB event level that triggered wake up is active. For AUX event interface to the AON domain, see Section 20.5.6.
For indirect wakeup, the System CPU application must use the sequence that follows:
Wakeup MCU
If not using TI-RTOS: configure AUX_COMB event to alert the System CPU
Select edge for AUX_EVCTL:EVTOMCUPOL.AUX_COMPB
Set AUX_EVCTL.EVTOMCUMASK.AUX_COMPB
Upon wakeup, System CPU clears the AON wakeup and the AUX_COMPB event
Write 1 to AUX_EVCTL:EVTOAONFLAGSCLR.AUX_COMPB
Write 1 to AUX_EVCTL:EVTOMCUFLAGSCLR.AUX_COMPB
If using TI-RTOS: set AON_EVENT:EVTOMCUSEL.AON_PROG_EV0=AUX_COMPB, and enable IRQ (29) for this event
Upon wakeup, write 1 to AUX_EVCTL:EVTOAONFLAGSCLR.AUX_COMPB