Oh this has easy answer: read the (fucking) manual;) nRF52 chips which support "NFC tag" interface are simply able to act as ISO14443 Type A PICC up to layer 4. Nothing more and nothing less. So whatever application (and NFC Forum NDEF Tag Type 4 or MIFARE DESFire are some of these) can work on top of this it could be implemented. Because the nRF52 HW supports only basic routines to do anticollision and transport frames across the radio you need some "stack" or "library" on top of it. Nordic helps you with supplying two closed source (= just binary "blob") libraries which seems to work well in order to emulate NFC Forum NDEF Tags type 2 and 4 (NXP Mifare Ultralight and NXP Mifare DESFire). But you are free to implement your own if you don't like them.
Oh this has easy answer: read the (fucking) manual;) nRF52 chips which support "NFC tag" interface are simply able to act as ISO14443 Type A PICC up to layer 4. Nothing more and nothing less. So whatever application (and NFC Forum NDEF Tag Type 4 or MIFARE DESFire are some of these) can work on top of this it could be implemented. Because the nRF52 HW supports only basic routines to do anticollision and transport frames across the radio you need some "stack" or "library" on top of it. Nordic helps you with supplying two closed source (= just binary "blob") libraries which seems to work well in order to emulate NFC Forum NDEF Tags type 2 and 4 (NXP Mifare Ultralight and NXP Mifare DESFire). But you are free to implement your own if you don't like them.
