摘要
介绍了一种利用TI公司推出的半双工RF芯片TRF6900作射频收发,MSP430作控制单元以时分的形式实现无线双工通信的方案。本设计采用模拟数字锁相环来实现位同步,控制器MSP430定时器的2个捕捉/比较寄存器模拟数字鉴相器和数字滤波器,用软件实现相位控制的方法来进行相位调整,MSP430的主定时器设为连续计数方式,定时器的一个寄存器设为比较方式,另一个寄存器设为捕捉方式。控制器在RF芯片接收的基带信号的中央去采样,以保证信号读取的正确,代价只是需要在每一帧的数据包之前要有一个不长的位同步序列,这个位同步序列是个方波序列。
We present a method of using half-duplex IC TRF6900 accomplish full-duplex data transmission. The TRF6900, a single chip transceiver for the new 868 MHz to 870 MHz European band and the North American 915 MHz ISM band, is controlled by MSP430 which is an ultra-low-power micro-controllers. MSP430 drive the transceiver via its serial interface by dividing time equally to accomplish the RF transmission. This paper described the approach of using MSP430's Timer to stimulate Phase-Locked Loops in order to realize bit-synchronization. For the purpose of sampling the data received from TRF6900 at center point of the data pulse, in this way data is reliable, the phase differ between MSP430's sampling and the edge of base-band pulse received from TRF6900 should be 180°. This method significantly reduce complexity of the hardware and fully utilize resource of the controller.
基金
2003年度高等学校博士学科点专项科研基金(20030290019)
