原标题：TI TRF7970A NFC有源和无源P2P通信参考设计

　　TI公司的trf7970A是多协议全集成的13.56-MHz RFID/NFC 收发器IC,支持NFC标准NFCIP-1 (ISO/IEC 18092)和NFCIP-2(ISO/IEC 21481),和ISO15693, ISO18000-3, ISO14443A/B以及 FeliCa兼容,并集成编码器,译码器和数据成帧,工作电压2.7V-5.5V,可编程输出功率+20 dBm (100 mW), +23 dBm (200 mW),主要用在移动设备(平板电脑,手机),短程无线通信,蓝牙和Wi-Fi等无线网络,公共交通,医疗设备,产品识别,POS和护照读系统,接入系统以及电子商务卡共享等.本文介绍了TRF7970A主要特性,框图,典型应用电路以及NFC有源和无源P2P通信参考设计主要特性,电路图和材料清单.

　　The TRF7970A device is an integrated analog front end and data-framing device for a 13.56-MHz RFID and Near Field Communication (NFC) system. Built-in programming options make the device suitable for a wide range of applications for proximity and vicinity identification systems.

　　The device can perform in one of three modes: RFID and NFC reader, NFC peer, or in card emulation mode. Built-in user-configurable programming options make the device suitable for a wide range of applications. The TRF7970A device is configured by selecting the desired protocol in the control registers. Direct access to all control registers allows fine tuning of various reader parameters as needed.

　　Documentation, reference designs, EVM, and source code TI MSP430 MCUs or ARM MCUs are available.

　　TRF7970A主要特性:

　　Supports Near Field Communication (NFC) Standards NFCIP-1 (ISO/IEC 18092) and NFCIP-2 (ISO/IEC 21481)

　　Completely Integrated Protocol Handling for ISO15693, ISO18000-3,ISO14443A/B, and FeliCa

　　Integrated Encoders, Decoders, and Data Framing for NFC Initiator, Active and Passive Target Operation for All Three Bit Rates (106 kbps, 212 kbps, 424 kbps) and Card Emulation

　　RF Field Detector With Programmable Wake-Up Levels for NFC Passive Transponder Emulation Operation

　　RF Field Detector for NFC Physical Collision Avoidance

　　Integrated State Machine for ISO14443A Anticollision (Broken Bytes) Operation (Transponder Emulation or NFC Passive Target)

　　Input Voltage Range: 2.7 VDC to 5.5 VDC

　　Programmable Output Power: +20 dBm (100 mW), +23 dBm (200 mW)

　　Programmable I/O Voltage Levels From 1.8 VDC to 5.5 VDC

　　Programmable System Clock Frequency Output (RF, RF/2, RF/4) from 13.56-MHz or 27.12-MHz Crystal or Oscillator

　　Integrated Voltage Regulator Output for Other System Components (MCU,Peripherals, Indicators),20 mA (Max)

　　Programmable Modulation Depth

　　Dual Receiver Architecture With RSSI for Elimination of "Read Holes" and Adjacent Reader System or Ambient In-Band Noise Detection

　　Programmable Power Modes for Ultra Low-Power System Design (Power Down <1 µA)

　　Parallel or SPI Interface (With 127-Byte FIFO)

　　Temperature Range: –40℃ to 110℃

　　32-Pin QFN Package (5 mm x 5 mm)

　　TRF7970A 应用:

　　• Mobile Devices (Tablets, Handsets)

　　• Short-Range Wireless Communication Tasks

　　• Secure Pairing ( Bluetooth®, Wi-Fi®, Other Paired (Firmware Updates)

　　Wireless Networks)

　　• Product Identification or Authentication

　　• Public Transport or Event Ticketing

　　• Medical Equipment or Consumables

　　• Passport or Payment (POS) Reader Systems

　　• Access Control, Digital Door Locks

　　• Sharing of Electronic Business Cards

　　图1. TRF7970A框图

　　图2. TRF7970A应用电路图:并行MCU接口

　　图3. TRF7970A应用电路图:SPI和SS模式MCU接口

　　NFC有源和无源P2P通信参考设计

　　This Near Field Communication (NFC) reference design provides a firmware example for implementing an NFC Peer to Peer (P2P) application. It is used for showing the application developer the correct way to implement a robust peer-to-peer project using the TRF7970A in both active and passive modes. The complexity of the Peer to Peer protocols and amount of NFC documentation that needs to be reviewed has traditionally been a barrier to developers creating NFC applications. This reference design solves this problem by providing a small number (five total) of easy to use Application Programming Interfaces (APIs). The documentation, hardware, and example code provided allows the designer to quickly implement NFC P2P functionality with an MSP430 or other MCU of choice.

　　NFC有源和无源P2P通信参考设计主要特性:

　　Proven interoperabilty with most commonly available NFC enabled mobile devices

　　Supports Simple NDEF Exchange Protocol (SNEP) and Logical Link Control Protocol (LLCP)

　　Passive and Active Modes as Initiator and Target at 106kbps, 212kbps and 424kbps

　　Includes easily configurable GUI Software which allows selection of individual mode(s)

　　GUI Software has throughput measurement capability and payload storage, used for validation

　　Offers a standalone mode along with the GUI, which both allow sending and receiving NDEF messages

　　图4.MSP430F5529实验板和TRF7970ATB硬件

　　NFC有源和无源P2P通信参考设计材料清单: