33.5.3 Interrupts

The EVSYS has the following interrupt sources for each channel:

  • Overrun Channel n interrupt (OVR)
  • Event Detected Channel n interrupt (EVD)

These interrupts events are asynchronous wake-up sources.

Each interrupt source has an interrupt flag associated with it. The interrupt flag in the corresponding Channel n Interrupt Flag Status and Clear (CHINTFLAG) register is set when the interrupt condition occurs.

Note: Interrupts must be globally enabled to allow the generation of interrupt requests.

Each interrupt can be individually enabled by writing a '1' to the corresponding bit in the Channel n Interrupt Enable Set (CHINTENSET) register, and disabled by writing a '1' to the corresponding bit in the Channel n Interrupt Enable Clear (CHINTENCLR) register. An interrupt request is generated when the interrupt flag is set and the corresponding interrupt is enabled. The interrupt request remains active until the interrupt flag is cleared, the interrupt is disabled or the Event System is reset. All interrupt requests are ORed together on system level to generate one combined interrupt request to the NVIC.

The user must read the Channel Interrupt Status (INTSTATUS) register to identify the channels with pending interrupts, and must read the Channel n Interrupt Flag Status and Clear (CHINTFLAG) register to determine which interrupt condition is present for the corresponding channel. It is also possible to read the Interrupt Pending register (INTPEND), which provides the highest priority channel with pending interrupt and the respective interrupt flags.