SPRUJF2A March 2026 – March 2026 AM13E23019
The event-trigger submodule monitors various event conditions (shown as inputs on the left side of Figure 18-35) and can be configured to prescale these events before issuing an Interrupt request or an ADC start of conversion. The event-trigger prescaling logic can issue interrupt requests and ADC start-of-conversion at:
A more detailed look at how the various register bits interact with the interrupt and ADC start-of-conversion logic are shown in Figure 18-36 and Figure 18-37.
Figure 18-36 shows the event-trigger interrupt generation logic. The interrupt-period (ETPERIOD[ETx_PERIOD]) bits specify the number of events required to cause an interrupt pulse to be generated. The choices available are:
The event that can cause an interrupt is configured by the interrupt enable(INTEN) register and event trigger selection (ETSEL) register. The event can be one of the following:
The number of events that have occurred can be read from the interrupt event counter ETCNT[ETx_CNT] register bits based off of the selection made using ETSEL. The specified event increments the ETCNT[ETx_CNT] bits until the bits reach the value specified by ETPERIOD[ETx_PERIOD]. When ETPS[INTCNT] = ETPS[INTPRD], the counter stops counting and the counter output is set. The counter is cleared when an INTFLAG[ETx] event is generated.
When ETCNT[ETx_CNT] reaches ETPERIOD[ETx_PERIOD], the following behavior occurs:
If interrupts are enabled, INTEN[ETx] = 1 and the interrupt flag is clear,INTFLAG[ETx] = 0, then an interrupt pulse is generated and the interrupt flag is set, INTFLAG[ETx] = 1. The counter is reset and begins counting events againWriting a 0 or a value that is less than the current ETCNT value to the ETPERIOD bits results in the counter going to an undefined state.
The previous definition means that an interrupt on every event up to 7 events if using the ETCNT and ETPERIOD can be generated.
Figure 18-36 Event-Trigger Interrupt Generator
Figure 18-37 shows the operation of the event-trigger's start-of-conversion (SOCx) pulse generator. The SOCCNT[SOCx_CNT] counters and SOCPERIOD[SOCx_PERIOD] period values behave similarly to the interrupt generator except that the pulses are continuously generated. That is, the pulse flag SOCFLAG[SOCx] is latched when a pulse is generated, but the interrupt generator does not stop further pulse generation. The enable and disable bit SOCEN[SOCx_ENABLE] stops pulse generation, but input events can still be counted until the period value is reached as with the interrupt generation logic. The event that triggers an SOCx pulse can be configured separately in the SOCSEL[SOCx_SEL] bits. The possible events are the same events that can be specified for the interrupt generation logic.
Figure 18-37 Event-Trigger Start-of-Conversion (SOC) Pulse Generator