SLOS743M August   2011  – March 2020

PRODUCTION DATA.  

  1. 1Device Overview
    1. 1.1 Features
    2. 1.2 Applications
    3. 1.3 Description
    4. 1.4 Functional Block Diagram
  2. 2Revision History
  3. 3Device Characteristics
    1. 3.1 Related Products
  4. 4Terminal Configuration and Functions
    1. 4.1 Pin Diagram
    2. 4.2 Signal Descriptions
      1. Table 4-1 Terminal Functions
  5. 5Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Electrical Characteristics
    5. 5.5 Thermal Resistance Characteristics
    6. 5.6 Switching Characteristics
  6. 6Detailed Description
    1. 6.1  Overview
      1. 6.1.1 RFID and NFC Operation – Reader and Writer
      2. 6.1.2 NFC Device Operation – Initiator
      3. 6.1.3 NFC Device Operation – Target
        1. 6.1.3.1 Active Target
        2. 6.1.3.2 Passive Target
        3. 6.1.3.3 Card Emulation
    2. 6.2  System Block Diagram
    3. 6.3  Power Supplies
      1. 6.3.1 Supply Arrangements
      2. 6.3.2 Supply Regulator Settings
      3. 6.3.3 Power Modes
    4. 6.4  Receiver – Analog Section
      1. 6.4.1 Main and Auxiliary Receivers
      2. 6.4.2 Receiver Gain and Filter Stages
    5. 6.5  Receiver – Digital Section
      1. 6.5.1 Received Signal Strength Indicator (RSSI)
        1. 6.5.1.1 Internal RSSI – Main and Auxiliary Receivers
        2. 6.5.1.2 External RSSI
    6. 6.6  Oscillator Section
    7. 6.7  Transmitter – Analog Section
    8. 6.8  Transmitter – Digital Section
    9. 6.9  Transmitter – External Power Amplifier and Subcarrier Detector
    10. 6.10 TRF7970A IC Communication Interface
      1. 6.10.1 General Introduction
        1. 6.10.1.1 Continuous Address Mode
        2. 6.10.1.2 Noncontinuous Address Mode (Single Address Mode)
        3. 6.10.1.3 Direct Command Mode
        4. 6.10.1.4 FIFO Operation
      2. 6.10.2 Parallel Interface Mode
      3. 6.10.3 Reception of Air Interface Data
      4. 6.10.4 Data Transmission From MCU to TRF7970A
      5. 6.10.5 Serial Interface Communication (SPI)
        1. 6.10.5.1 Serial Interface Mode With Slave Select (SS)
      6. 6.10.6 Direct Mode
    11. 6.11 TRF7970A Initialization
    12. 6.12 Special Direct Mode for Improved MIFARE Compatibility
    13. 6.13 NFC Modes
      1. 6.13.1 Target
      2. 6.13.2 Initiator
    14. 6.14 Direct Commands from MCU to Reader
      1. 6.14.1 Command Codes
        1. 6.14.1.1  Idle (0x00)
        2. 6.14.1.2  Software Initialization (0x03)
        3. 6.14.1.3  Initial RF Collision Avoidance (0x04)
        4. 6.14.1.4  Response RF Collision Avoidance (0x05)
        5. 6.14.1.5  Response RF Collision Avoidance (0x06, n = 0)
        6. 6.14.1.6  Reset FIFO (0x0F)
        7. 6.14.1.7  Transmission With CRC (0x11)
        8. 6.14.1.8  Transmission Without CRC (0x10)
        9. 6.14.1.9  Delayed Transmission With CRC (0x13)
        10. 6.14.1.10 Delayed Transmission Without CRC (0x12)
        11. 6.14.1.11 Transmit Next Time Slot (0x14)
        12. 6.14.1.12 Block Receiver (0x16)
        13. 6.14.1.13 Enable Receiver (0x17)
        14. 6.14.1.14 Test Internal RF (RSSI at RX Input With TX ON) (0x18)
        15. 6.14.1.15 Test External RF (RSSI at RX Input with TX OFF) (0x19)
    15. 6.15 Register Description
      1. 6.15.1 Register Preset
      2. 6.15.2 Register Overview
      3. 6.15.3 Detailed Register Description
        1. 6.15.3.1 Main Configuration Registers
          1. 6.15.3.1.1 Chip Status Control Register (0x00)
          2. 6.15.3.1.2 ISO Control Register (0x01)
        2. 6.15.3.2 Control Registers – Sublevel Configuration Registers
          1. 6.15.3.2.1  ISO/IEC 14443 TX Options Register (0x02)
          2. 6.15.3.2.2  ISO/IEC 14443 High-Bit-Rate and Parity Options Register (0x03)
          3. 6.15.3.2.3  TX Timer High Byte Control Register (0x04)
          4. 6.15.3.2.4  TX Timer Low Byte Control Register (0x05)
          5. 6.15.3.2.5  TX Pulse Length Control Register (0x06)
          6. 6.15.3.2.6  RX No Response Wait Time Register (0x07)
          7. 6.15.3.2.7  RX Wait Time Register (0x08)
          8. 6.15.3.2.8  Modulator and SYS_CLK Control Register (0x09)
          9. 6.15.3.2.9  RX Special Setting Register (0x0A)
          10. 6.15.3.2.10 Regulator and I/O Control Register (0x0B)
        3. 6.15.3.3 Status Registers
          1. 6.15.3.3.1  IRQ Status Register (0x0C)
          2. 6.15.3.3.2  Interrupt Mask Register (0x0D) and Collision Position Register (0x0E)
          3. 6.15.3.3.3  RSSI Levels and Oscillator Status Register (0x0F)
          4. 6.15.3.3.4  Special Functions Register (0x10)
          5. 6.15.3.3.5  Special Functions Register (0x11)
          6. 6.15.3.3.6  Adjustable FIFO IRQ Levels Register (0x14)
          7. 6.15.3.3.7  NFC Low Field Level Register (0x16)
          8. 6.15.3.3.8  NFCID1 Number Register (0x17)
          9. 6.15.3.3.9  NFC Target Detection Level Register (0x18)
          10. 6.15.3.3.10 NFC Target Protocol Register (0x19)
        4. 6.15.3.4 Test Registers
          1. 6.15.3.4.1 Test Register (0x1A)
          2. 6.15.3.4.2 Test Register (0x1B)
        5. 6.15.3.5 FIFO Control Registers
          1. 6.15.3.5.1 FIFO Status Register (0x1C)
          2. 6.15.3.5.2 TX Length Byte1 Register (0x1D), TX Length Byte2 Register (0x1E)
  7. 7Applications, Implementation, and Layout
    1. 7.1 TRF7970A Reader System Using SPI With SS Mode
      1. 7.1.1 General Application Considerations
      2. 7.1.2 Schematic
    2. 7.2 Layout Considerations
    3. 7.3 Impedance Matching TX_Out (Pin 5) to 50 Ω
    4. 7.4 Reader Antenna Design Guidelines
  8. 8Device and Documentation Support
    1. 8.1 Getting Started and Next Steps
    2. 8.2 Device Nomenclature
    3. 8.3 Tools and Software
    4. 8.4 Documentation Support
    5. 8.5 Support Resources
    6. 8.6 Trademarks
    7. 8.7 Electrostatic Discharge Caution
    8. 8.8 Glossary
  9. 9Mechanical, Packaging, and Orderable Information

6.10.4 Data Transmission From MCU to TRF7970A

Before beginning data transmission, the FIFO should always be cleared with a reset command (0x0F). Data transmission is initiated with a selected command (see Section 6.14). The MCU then commands the reader to do a continuous write command (0x3D) starting from register 0x1D. Data written into register 0x1D is the TX Length Byte 1 (upper and middle nibbles), while the following byte in register 0x1E is the TX Length Byte 2 (lower nibble and broken byte length) (see Table 6-57 and Table 6-58) . Note that the TX byte length determines when the reader sends the end of frame (EOF) byte. After the TX length bytes are written, FIFO data is loaded in register 0x1F with byte storage locations 0 to 127. Data transmission begins automatically after the first byte is written into the FIFO. The loading of TX length bytes and the FIFO can be done with a continuous-write command, as the addresses are sequential.

At the start of transmission, the flag B7 (IRQ_TX) is set in the IRQ Status register, and at the end of the transmit operation, an interrupt is sent to inform the MCU that the task is complete.