MSP430F4152 SPI 问题

只看该作者 · 2011-3-28 21:25

用UCB0端口做了4线的SPI，DCO倍频至2M，赋给SMCLK，SMCLK用作SPI的时钟源，但是实际量到的SPICLK只有50HZ，还请大家帮忙看一下程序的问题出在哪？谢谢！

#include "msp430f4152.h"
#define uchar unsigned char
#define uint unsigned int
void main( void )
{
  uint i;
  // Stop watchdog timer to prevent time out reset
  WDTCTL = WDTPW + WDTHOLD;
  FLL_CTL0 &=~XTS_FLL;
  FLL_CTL0 |=XCAP11PF;
  /*时钟配置*/
  SCFQCTL =SCFQ_2M;          //MCLK=64ACLK
  FLL_CTL1 &=~SMCLKOFF;    //SMCLK使能
do
  {
IFG1 &=~OFIFG;          //清除中断标志
for(i=0;i<0x47ff;i++);
  }while((IFG1&OFIFG));

  P6DIR |=BIT3;
  P6OUT |=BIT3;             //P6.3置高

  /****模块初始化****/
  _BIC_SR(GIE);             //关闭总中断

  /*初始化RS232*/
  UCA0CTL1 |=UCSWRST;       //置位SWRST
  UCA0CTL0 &=~UCPEN;       //无奇偶校验
  UCA0CTL0 &=~UC7BIT;       //8位数据
  UCA0CTL0 &=~UCSPB;       //1位停止位
  UCA0CTL0 &=~(UCMODE1+UCMODE0+UCSYNC);//UART模式
  UCA0CTL1 |=UCSSEL0;       //ACLK作为时钟源

  UCA0BR0  =0x03;
  UCA0BR1  =0x00;
  UCA0MCTL =0x06;          //波特率为9600

  P6SEL |=BIT5+BIT6;       //P6.5,P6.6设置为UART模式
  UCA0CTL1 &=~UCSWRST;          //清零SWRST

  /*初始化SPI*/
  P6SEL |=BIT1+BIT2+BIT4; //P6.1,P6.2,P6.4设置为SPI模式
  UCB0CTL1 |=UCSWRST;
  UCB0CTL0 |=UCMST+UCSYNC+UCCKPH+UCCKPL+UCMSB; //采用同步方式

// UCB0CTL0 |=UCMODE1;          //4线SPI,片选低有效

  UCB0CTL1 |=UCSSEL_2;          //SMCLK做时钟源
  UCB0BR0 =0x02;
  UCB0BR1 =0x00;                //SPI时钟频率为4M(SMCLK)

  UCB0CTL1 &=~UCSWRST;          //清零SWRST

  IE2 |=UCA0RXIE;                //使能RS232接收中断
// IE2 |=UCB0RXIE;             //使能SPI接收中断
  _BIS_SR(GIE);                   //使能总中断
  UCA0TXBUF =0x55;
  while((IFG2&UCA0TXIFG)==0);
  IFG2 &=~UCA0TXIFG;
                                 //置低P6.3,SPI片选端
  P6OUT &=~BIT3;
  for(i=50;i>0;i--);
  UCB0TXBUF =0x80;             //读ADXL345ID
  while((IFG2&UCB0TXIFG)==0);
  IFG2 &=~UCB0TXIFG;
  i=0;
  while((IFG2&UCB0RXIFG)==0);
  IFG2 &=~UCB0RXIFG;
  i=UCB0RXBUF;
  UCA0TXBUF=i;
  while((IFG2&UCA0TXIFG)==0);
  IFG2 &=~UCA0TXIFG;
  for(i=50;i>0;i--);
  P6OUT |=BIT3;
  while(1);
}
#pragma vector =USCIAB0RX_VECTOR
__interrupt void UART0_RX(void)
{
  uchar i;
  if(IFG2&UCA0RXIFG)
  {
IE2 &=~UCA0RXIE;
IFG2 &=~UCA0RXIFG;

i =UCA0RXBUF;
UCA0TXBUF =i+1;
while((IFG2&UCA0TXIFG)==0);
IFG2 &=~UCA0TXIFG;
IE2 |=UCA0RXIE;
  }
  else
  {
IE2 &=~UCB0RXIE;
IFG2 &=~UCB0RXIFG;
UCA0TXBUF =0x77;
while((IFG2&UCA0TXIFG)==0);
IFG2 &=~UCA0TXIFG;
UCA0TXBUF =UCB0RXBUF;
while((IFG2&UCA0TXIFG)==0);
IFG2 &=~UCA0TXIFG;
IE2 |=UCB0RXIE;
  }
}