收藏本站
TRF7970A
SLOS743K – AUGUST 2011 – REVISED APRIL 2014
www.ti.com
6.10.4 Data Transmission to MCU
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 6.13 ). 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.
6.10.5 Serial Interface Communication (SPI)
When an SPI interface is used, I/O pins I/O_2, I/O_1, and I/O_0 must be hard wired according to Table 6-
10 . On power up, the TRF7970A looks for the status of these pins and then enters into the corresponding
mode.
The choice of one of these modes over another should be predicated by the available GPIOs and the
desired control of the system.
The serial communications work in the same manner as the parallel communications with respect to the
FIFO, except for the following condition. On receiving an IRQ from the reader, the MCU reads the
TRF7970A IRQ Status register to determine how to service the reader. After this, the MCU must to do a
dummy read to clear the reader's IRQ status register. The dummy read is required in SPI mode because
the reader's IRQ status register needs an additional clock cycle to clear the register. This is not required in
parallel mode because the additional clock cycle is included in the Stop condition. When first establishing
communications with the TRF7970A, the SOFT_INIT (0x03) and IDLE (0x00) commands should be sent
first from the MCU (see Table 6-19 ).
36
Detailed Description
Submit Documentation Feedback
Product Folder Links: TRF7970A
Copyright ? 2011–2014, Texas Instruments Incorporated
发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

*型号 *数量 厂商 批号 封装
添加更多采购

我的联系方式

*
*
*
相关PDF资料
TRM-418-LT TRANSCEIVER RF 418MHZ LT SERIES
TRM-900-NT RF TXRX 915MHZ NT SERIES
TRX08GVP2540 TXRX OPT SCFF 8.5GB/S 850NM
TS-320240BRNO TCH PANEL 140X104 RESISTIVE MONO
TS-TFT3.5Z TOUCH PANEL 140X1.4.0 TFT
TS3-75B3 SENSOR THERMAL MOXIE NTC 75C
TSL26711FN IC PROXIMITY DETECTOR 6-DFN
TSOP57238TT1 IC IR RCVR MODULE 38KHZ
相关代理商/技术参数
TRF7970ARHBR 功能描述:IC RFID/NFC AFE 13.56MHZ 32QFN RoHS:是 类别:RF/IF 和 RFID >> RFID IC 系列:- 其它有关文件:CR14 View All Specifications 标准包装:1 系列:- RF 型:收发器 频率:13.56MHz 特点:ISO14443-B 封装/外壳:16-SOIC（0.154"，3.90mm 宽） 供应商设备封装:16-SO 包装:Digi-Reel® 其它名称:497-5719-6
TRF7970ARHBT 功能描述:IC RFID/NFC AFE 13.56MHZ 32QFN RoHS:是 类别:RF/IF 和 RFID >> RFID IC 系列:- 其它有关文件:CR14 View All Specifications 标准包装:1 系列:- RF 型:收发器 频率:13.56MHz 特点:ISO14443-B 封装/外壳:16-SOIC（0.154"，3.90mm 宽） 供应商设备封装:16-SO 包装:Digi-Reel® 其它名称:497-5719-6
TRF7970ATB 功能描述:RFID应答器 TRF7970A Target Brd RoHS:否 制造商:Murata 存储容量:512 bit 工作温度范围:- 40 C to + 85 C 安装风格:SMD/SMT 封装 / 箱体: 封装:Reel
TRF79A6AA17LB000 制造商:Opnext 功能描述:XFP FORM FACTOR - Boxed Product (Development Kits)
TRF79A6AA18LB000 制造商:Opnext 功能描述:XFP FORM FACTOR - Boxed Product (Development Kits)
TRF79A6AA19LB000 制造商:Opnext 功能描述:XFP FORM FACTOR - Boxed Product (Development Kits)
TRF79A6AA20LB000 制造商:Opnext 功能描述:XFP FORM FACTOR - Boxed Product (Development Kits)
TRF79A6AA21LB000 制造商:Opnext 功能描述:XFP FORM FACTOR - Boxed Product (Development Kits)