SLOA192B April   2014  – March 2019 TRF7970A , TRF7970A

 

  1.   NFC active and passive peer-to-peer communication using the TRF7970A
    1.     Trademarks
    2. Introduction
    3. Initial RF Collision
    4. TRF7970A Register Settings
    5. Peer-to-Peer at 106 kbps
      1. 4.1 Active Communication
        1. 4.1.1 Initiator
        2. 4.1.2 Target
      2. 4.2 Passive Communication
        1. 4.2.1 Initiator
        2. 4.2.2 Target
    6. Peer-to-Peer at 212 kbps and 424 kbps
      1. 5.1 Active Communication
        1. 5.1.1 Initiator
        2. 5.1.2 Target
      2. 5.2 Passive Communication
        1. 5.2.1 Initiator
        2. 5.2.2 Target
    7. Hardware Description
      1. 6.1 LaunchPad™ Development Kit and BoosterPack™ Plug-in Module Setup
        1. 6.1.1 BoosterPack Plug-in Module: DLP-7970ABP
        2. 6.1.2 LaunchPad Development Kit: MSP-EXP430F5529LP
        3. 6.1.3 LaunchPad Development Kit: MSP-EXP432P401R
      2. 6.2 Bundle Available for Purchase
    8. Passive and Active Peer-to-Peer Firmware Example
      1. 7.1 Peer-to-Peer APIs
      2. 7.2 Implementing a Peer-to-Peer Sample Application
        1. 7.2.1 Low-Level Initialization
        2. 7.2.2 Peer-to-Peer NFC Stack Setup
        3. 7.2.3 Sending NDEF Packets
        4. 7.2.4 Receiving NDEF Packets
    9. Quick Start Guide
    10. Operational Overview
    11. 10 Peer-to-Peer Interoperability Results
    12. 11 Conclusion
    13. 12 References
  2.   Revision History

Target

Initially the TRF7970A must be receiving without CRC. After receiving commands from the initiator, the following registers must be modified before and after the anticollision is completed:

  1. ISO Control register (0x01) → 0xA4 (ISO14443A 106 kbps, receive without CRC during anticollision, before Select command)
    or
    ISO Control register (0x01) → 0x24 (ISO14443A 106 kbps, receive with CRC, after anticollision is completed).
  2. 2. Send packet:
    1. Reset FIFO (0x0F) direct command.
    2. Transmission without (0x10, anticollision before Select command) or with (0x11, after anticollision is completed) CRC direct command.
    3. c. TX Length Byte 1 and 2 (0x1D and 0x1E) registers.
    4. Write the command to the FIFO.

The ISO control register needs to be modified for the anticollision state to receive without CRC for the required commands. For more information, see the ISO14443-3 specification. Once the anticollision is completed the ISO Control register needs to be modified to receive with CRC. Step 2 must be used to send commands to the initiator.

peer_to_peer_106kbps_initiator_anti_collision_for_passive_comm_sloa192.gifFigure 9. Peer-to-Peer 106-kbps Initiator Anticollision for Passive Communication