msp430f2471

觉得程序的问题可能性比较大,注意spi通讯的时序.

但也有可能是电路的问题,不容易猜到

     SPI 通讯方面似乎只有初始化要注意，我的初始化程序如下：

void  SPI_Init(void)
{ 
  P5SEL |= 0x0E;                            // P5.3,2,1 option select
  UCB1CTL1 |= UCSWRST;
  UCB1CTL0 |= UCMST + UCMSB + UCSYNC    //3-pin, 8-bit SPI master  
  UCB1CTL1 |= UCSSEL_2;                                    // SMCLK
  UCB1BR0 = 2;                          
  UCB1BR1 = 0;                              
  UCB1CTL1 &= ~UCSWRST;                     // **Initialize USCI state machine**
}

与1298通讯片段如下：

BYTE  ADS_Init(void)
{
      BYTE i;
      while(UCB1STAT & UCBUSY);
      UCB1TXBUF = SDATAC;                       //Stop Read Data Continuously mode
      for(i = 0; i < 0x40; i ++)
        _NOP();
      while(UCB1STAT & UCBUSY);
      UCB1TXBUF = 0x20;                           // Read From Register   001r rrrr, where r rrrr is the starting register address.  
      while(UCB1STAT & UCBUSY);
      UCB1TXBUF = 0x00;                         // 000n nnnn, where n nnnn is the number of registers to read – 1.

      while(UCB1STAT & UCBUSY);
      UC1IFG &= ~UCB1RXIFG;
      UCB1TXBUF = 0x00;                   
      while (!(UC1IFG & UCB1RXIFG));
      i = UCB1RXBUF;

     return  i;

}

由于大多数情况下运行正常，程序中我也找不出错误，请指点下还有要注意的地方吗？ 谢谢！