NFC active and passive P2P comm with TRF7970A

The TRF7970A supports three modes: Reader/Writer, Card Emulation, and Peer-to-Peer. This document focuses on how to use the TRF7970A in peer-to-peer (P2P) active or passive. P2P requires two NFC enabled devices to communicate using technologies NFC-A or NFC-F at baud rates of 106 kbps (NFC-A), 212 kbps (NFC-F), or 424 kbps (NFC-F). The transceiver that is initially polling and initiates the communication is the initiator. The transceiver that is initially listening is the target.

The initiator always generates the RF field for both active and passive communication modes. However, the target generates its own RF field only for active mode (while the initiator's RF field is disabled), and load modulates the initiator's RF field in passive mode. Once the technology selection for either mode has been completed, the higher layers are the same. The NDEF Push Protocol (NPP) was commonly used on Gingerbread Android NFC devices as the protocol to push NDEF messages from one NFC device to another; however, the Simple NDEF Exchange Protocol (SNEP) has become the standard on Ice Cream Sandwich Android NFC devices and onward.

View the PDF document for more information.

Originally published by Texas Instruments Inc. at www.ti.com as "NFC Active and Passive Peer-to-Peer Communication Using the TRF7970A".