User's Manual
Table Of Contents
- 1 Device Overview
- Table of Contents
- 2 Revision History
- 3 Device Characteristics
- 4 Terminal Configuration and Functions
- 5 Specifications
- 6 Detailed Description
- 6.1 Overview
- 6.2 System Block Diagram
- 6.3 Power Supplies
- 6.4 Receiver – Analog Section
- 6.5 Receiver – Digital Section
- 6.6 Oscillator Section
- 6.7 Transmitter – Analog Section
- 6.8 Transmitter – Digital Section
- 6.9 Transmitter – External Power Amplifier and Subcarrier Detector
- 6.10 TRF7970A IC Communication Interface
- 6.11 Special Direct Mode for Improved MIFARE Compatibility
- 6.12 NFC Modes
- 6.13 Direct Commands from MCU to Reader
- 6.13.1 Command Codes
- 6.13.1.1 Idle (0x00)
- 6.13.1.2 Software Initialization (0x03)
- 6.13.1.3 Initial RF Collision Avoidance (0x04)
- 6.13.1.4 Response RF Collision Avoidance (0x05)
- 6.13.1.5 Response RF Collision Avoidance (0x06, n = 0)
- 6.13.1.6 Reset (0x0F)
- 6.13.1.7 Transmission With CRC (0x11)
- 6.13.1.8 Transmission Without CRC (0x10)
- 6.13.1.9 Delayed Transmission With CRC (0x13)
- 6.13.1.10 Delayed Transmission Without CRC (0x12)
- 6.13.1.11 Transmit Next Time Slot (0x14)
- 6.13.1.12 Block Receiver (0x16)
- 6.13.1.13 Enable Receiver (0x17)
- 6.13.1.14 Test Internal RF (RSSI at RX Input With TX ON) (0x18)
- 6.13.1.15 Test External RF (RSSI at RX Input with TX OFF) (0x19)
- 6.13.1.16 Receiver Gain Adjust (0x1A)
- 6.13.1 Command Codes
- 6.14 Register Description
- 7 Application Schematic and Layout Considerations
- 8 Device and Documentation Support
- 9 Mechanical Packaging and Orderable Information
TRF7970A
SLOS743K –AUGUST 2011–REVISED APRIL 2014
www.ti.com
The main register controlling the digital part of the receiver is the ISO Control register (address 0x01). By
writing to this register, the user selects the protocol to be used. At the same time (with each new write in
this register) the default preset in all related registers is done, so no further adjustments in other registers
are needed for proper operation. Table 6-6 shows the coding of the ISO Control register (0x01).
Table 6-6. Coding of the ISO Control Register
Bit Signal Name Function Comments
1 = No RX CRC
B7 rx_crc_n Receiving without CRC
0 = RX CRC
0 = output is subcarrier data
B6 dir_mode Direct mode type
1 = output is bit stream and clock from decoder selected by ISO bits
0 = RFID reader mode
B5 rfid RFID mode
1 = NFC or Card Emulator mode
RFID: Mode selection
NFC:
B4 iso_4 RFID protocol, NFC target
0 = NFC target
1 = NFC initiator
RFID: Mode selection (see Table 6-7)
NFC:
B3 iso_3 RFID protocol, NFC mode
0 = passive mode
1 = active mode
RFID: Mode selection
NFC:
B2 iso_2 RFID protocol, Card Emulation
0 = NFC normal modes
1 = Card Emulation mode
RFID: Mode selection
B1 iso_1 RFID protocol, NFC bit rate
NFC: Bit rate selection or Card Emulation selection (see Table 6-8)
RFID: Mode selection
B0 iso_0 RFID protocol, NFC bit rate
NFC: Bit rate selection or Card Emulation selection (see Table 6-8)
Table 6-7. Coding of the ISO Control Register For RFID Mode (B5 = 0)
Iso_4 Iso_3 Iso_2 Iso_1 Iso_0 Protocol Remarks
0 0 0 0 0 ISO15693 low bit rate, one subcarrier, 1 out of 4
0 0 0 0 1 ISO15693 low bit rate, one subcarrier, 1 out of 256
0 0 0 1 0 ISO15693 high bit rate, one subcarrier, 1 out of 4 Default for RFID IC
0 0 0 1 1 ISO15693 high bit rate, one subcarrier, 1 out of 256
0 0 1 0 0 ISO15693 low bit rate, double subcarrier, 1 out of 4
0 0 1 0 1 ISO15693 low bit rate, double subcarrier, 1 out of 256
0 0 1 1 0 ISO15693 high bit rate, double subcarrier, 1 out of 4
0 0 1 1 1 ISO15693 high bit rate, double subcarrier, 1 out of 256
0 1 0 0 0 ISO14443A, bit rate 106 kbps
RX bit rate when TX rate
0 1 0 0 1 ISO14443 A high bit rate 212 kbps different from RX rate (see
register 0x03)
24 Detailed Description Copyright © 2011–2014, Texas Instruments Incorporated
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