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
Figure 6-25. Continuous Read of FIFO After Inventory Command
At this point, it is good form to reset the FIFO and then read out the RSSI value of the tag. In this case the
transponder is very close to the antenna, so value of 0x7F is recovered.
Figure 6-26. Reset FIFO and Read RSSI
42 Detailed Description Copyright © 2011–2014, Texas Instruments Incorporated
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