SLOA192B April 2014 – March 2019 TRF7970A , TRF7970A
-
NFC active and passive peer-to-peer communication using the TRF7970A
- Trademarks
- 1 Introduction
- 2 Initial RF Collision
- 3 TRF7970A Register Settings
- 4 Peer-to-Peer at 106 kbps
- 5 Peer-to-Peer at 212 kbps and 424 kbps
- 6 Hardware Description
- 7 Passive and Active Peer-to-Peer Firmware Example
- 8 Quick Start Guide
- 9 Operational Overview
- 10 Peer-to-Peer Interoperability Results
- 11 Conclusion
- 12 References
- Revision History
4.1.2 Target
After receiving commands from the initiator, the transceiver must follow the next steps each time before responding to the initiator:
- Delay time specified in the technology specification (56 µs to 188 µs).
- Perform Response RF Collision avoidance, and ensure no RF field is detected.
- ISO Control register (0x01) → 0x08 (ISO14443A at 106 kbps, receive with CRC).
- Delay 1 ms
- Send packet:
- Reset FIFO (0x0F) direct command.
- Transmission with (0x11) or without (0x10) CRC direct command.
- TX Length Byte 1 and 2 (0x1D and 0x1E) registers.
- Write the response to the FIFO.
Figure 8. Peer-to-Peer 106-kbps Initiator Anticollision for Active Communication