SLOA208B November   2014  – March 2019 TRF7970A , TRF7970A

 

  1.   NFC card emulation using the TRF7970A
    1.     Trademarks
    2.     Terms, Definitions, and Symbols
    3. 1  Introduction
    4. 2  Card Emulation
      1. 2.1 Anticollision
        1. 2.1.1 Card Emulation Type A
        2. 2.1.2 Card Emulation Type B
      2. 2.2 Data Exchange
    5. 3  Configuration and Commands for Type 4 Tag Platforms
      1. 3.1 Overview of Type 4 Tag Configuration
        1. 3.1.1 Tag
        2. 3.1.2 Applications
        3. 3.1.3 Files
      2. 3.2 Firmware Structure
        1.       Example 1. Type 4 Tag Structures Within Example Firmware
        2. 3.2.1 tType4AppDS
        3. 3.2.2 tType4App
        4. 3.2.3 tType4File
        5. 3.2.4 Example Setup
          1.        Example 2. Example Setup of a Type 4 Tag Structure
      3. 3.3 File Structure
        1. 3.3.1 Capability Container
          1.        Example 3. Format of the Capability Container for a Tag With Two Files
        2. 3.3.2 Text RTD
          1.        Example 4. Example of a Text RTD Within an NDEF File
        3. 3.3.3 URI RTD
          1.        Example 5. Example of a URI RTD Within a Proprietary File
        4. 3.3.4 Smart Poster
        5. 3.3.5 V-Card
        6. 3.3.6 MIME
      4. 3.4 Available Type 4 Tag Commands
        1. 3.4.1 Frame Format
        2. 3.4.2 Select
        3. 3.4.3 Read Binary
        4. 3.4.4 Update Binary
      5. 3.5 Modifying Stored Tag Information
    6. 4  Hardware Description
      1. 4.1 LaunchPad™ Development Kit and BoosterPack™ Plug-in Module Setup
        1. 4.1.1 BoosterPack Plug-in Module: DLP-7970ABP
        2. 4.1.2 LaunchPad Development Kit: MSP-EXP430F5529LP
        3. 4.1.3 LaunchPad Development Kit: MSP-EXP432P401R
      2. 4.2 Bundle Available for Purchase
    7. 5  Card Emulation Firmware Example
      1. 5.1 Card Emulation APIs
      2. 5.2 Implementing a Card Emulation Sample Application
        1. 5.2.1 Low-Level Initialization
          1.        Example 6. MCU and TRF7970A Initialization Code Snippet
        2. 5.2.2 Card Emulation NFC Stack Setup
          1.        Example 7. Card Emulation Initialization Code
        3. 5.2.3 Emulation of Different RTDs
    8. 6  Quick Start Guide
    9. 7  Operational Overview
    10. 8  Card Emulation Interoperability Results
    11. 9  Conclusion
    12. 10 References
  2.   Revision History

2.2 Data Exchange

After the anticollision procedures for Type A or Type B are completed, the data exchange layer is entered. Within the data exchange layer, the commands for Type 4A and Type 4B tag platforms are identical. Both Platforms also use the same frame formats.

The frame format for DEP packets at 106 kbps during data exchange (see Figure 7) is different than the frame format during anticollision. Depending on the command that is issued by the device only certain optional bytes are included.

fig07_frame_iso_7816-4.gifFigure 7. Frame Format for ISO 7816-4 Data Exchange Commands

The commands used by both tag platforms use the ISO 7816-4 specifications and are further defined in the NFC Forum T4TOP specifications. When an NFC enabled reader/writer is presented, the firmware allows for the selection of either supported tag type (Type 4A/B) during the anticollision process and then enters the data exchange layer.

Because the data exchange layer supports DEP commands for both tag platforms, the firmware allows has been designed to minimize size by using the same layer for both tag types. This is accomplished by only having a distinction between Type 4A and Type 4B tag platforms in the technology detection and anticollision sequences. This modularity gives the TRF7970A a more robust experience than basic static tags that are constrained to only working with one reader/writer type.