SLOA227B October   2015  – March 2019 TRF7964A , TRF7964A , TRF7970A , TRF7970A

 

  1.   NFC/HF RFID reader/writer using the TRF7970A
    1.     Trademarks
    2. 1  Terms, Definitions, and Symbols
    3. 2  Introduction
    4. 3  Initial RF Collision
    5. 4  TRF7970A Register Settings
    6. 5  Reader/Writer Mode
      1. 5.1 Technology Activation Using the TRF7970A
        1. 5.1.1 ISO14443-3 Type A (Type 2 and Type 4A Tags)
          1. 5.1.1.1 Additional Tag Activation Commands for Type 4A Tags
        2. 5.1.2 ISO14443B-3 (Type 4B Tags)
          1. 5.1.2.1 Selection for Type 4B Tags
        3. 5.1.3 ISO18092 (Type 3 Tags)
        4. 5.1.4 ISO15693 (Type 5 Tags)
      2. 5.2 Tag Memory Format With NDEF Examples
        1. 5.2.1 Type 2 Tags
          1. 5.2.1.1 Layout
          2. 5.2.1.2 NDEF Format
            1. 5.2.1.2.1 Static Memory Structure
            2. 5.2.1.2.2 Dynamic Memory Structure
          3. 5.2.1.3 Capability Container
        2. 5.2.2 Type 3 Tags
          1. 5.2.2.1 Layout
          2. 5.2.2.2 NDEF Format
          3. 5.2.2.3 Attribute Information Block
        3. 5.2.3 Type 4 Tags
          1. 5.2.3.1 Layout
          2. 5.2.3.2 NDEF Format
          3. 5.2.3.3 Capability Container
        4. 5.2.4 Type 5 Tags
          1. 5.2.4.1 Layout
          2. 5.2.4.2 NDEF Format
          3. 5.2.4.3 Capability Container
    7. 6  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. 7  Reader/Writer Firmware Example
      1. 7.1 Reader/Writer APIs
      2. 7.2 Implementing a Reader/Writer Sample Application
        1. 7.2.1 Low-Level Initialization
          1.        Example 1. MCU and TRF7970A Initialization Code Snippet
        2. 7.2.2 Reader/Writer NFC Stack Configuration
          1.        Example 2. Reader/Writer Stack Configuration Code Snippet
        3. 7.2.3 Activation
        4. 7.2.4 Reading and Writing Tags
    9. 8  Quick Start Guide
    10. 9  Operational Overview
    11. 10 Reader/Writer Interoperability Results
    12. 11 Conclusion
    13. 12 References
  2.   Revision History

5.1.1 ISO14443-3 Type A (Type 2 and Type 4A Tags)

The frame format for ISO14443A packets at 106 kbps during anticollision(shown in Figure 8) is based on NFC-A technology specifications in NFCForum-TS-DigitalProtocol-1.0 and the ISO 14443-3 Specifications. The Type A frame format does not include CRC bytes when sending anticollision commands, but does include the CRC bytes when sending tag selection and data exchange command.

fig08_ISO14443A_Frame_Format.gifFigure 8. ISO14443A Frame Format

When the initial RF collision is completed and no RF field has been detected (as shown in Figure 7) the following registers must be modified before and after the anticollision is completed (see Figure 9). For more information, see Section 3.

  • ISO Control register (0x01) = 0x88 (ISO14443A at 106 kbps, receive without CRC during anticollision, before Select command)
    or
    ISO Control register (0x01) = 0x08 (ISO14443A at 106 kbps, receive with CRC after anticollision is completed).
  • Send packet:
    • Reset FIFO (0x0F) direct command.
    • Transmission without (0x10, anticollision before Select command) or with (0x11, after anticollision is completed) CRC direct command.
    • TX Length Byte 1 (0x1D) and TX Length Byte 2 (0x1E) registers.
    • Write the command to the FIFO.

In the context of Type A, anticollision refers to the mandatory process for the retrieval of the UID, and does not imply support for detecting multiple Type A tags presented at the same time.

The ISO control register must be modified for the anticollision state to receive without CRC for the required commands (see the ISO14443-3 specification for more information). When the anticollision is completed, the ISO Control register must be modified to receive with CRC. Step 2 must be used to send commands to the passive target.

fig09_RW_Anticoll_ISO14443A.gifFigure 9. Reader/Writer Anticollision for ISO14443A