Does the NFC Type 4 library globally disable interrupts at any point?

[CurtisHx]

Does the NFC library globally disable interrupts at any point? We're trying to track down an issue where our code occasionally misses an I2C event during NFC read/write.

[Michal]

Yes, the NFC library can globally disable interrupts through nrf_drv_clock module, look for CRITICAL_REGION_ENTER() and CRITICAL_REGION_EXIT() macros (using critical sections for RMW operations on driver's state variables). The nrf_drv_clock is used for controlling oscillators. NFC can only be enabled when a high precession crystal oscillator is running.

But even if IRQs are disabled, the I2C events should be set as pending and should fire when the interrupts are enabled again.

[CurtisHx]

Thanks for the update. Turns out our problem was not related to the NFC Library disabling / enabling interrupts. It was caused by a timing problem in our code. Good to know about the NFC interrupts, though.

[CurtisHx]

To answer my own question: No, the NFC Type 4 library does not globally disable interrupts.