MSP430的外部中断能否用查询方式实现

只看该作者 · 2011-11-5 22:59

请问MSP430的IO口设置为外部中断引脚时，必须用中断子程序实现，而用主程序中查询PxIFGx的方法处理外部中断事件是无法实现的吗，每次调试都不对，程序如下：

#include  <msp430x24x.h>
char data;
#define LED_ON  P2OUT &=~0x04;
#define LED_OFF  P2OUT |= 0x04;
void delay(unsigned long int dl)
{
while(dl--);
}
void clock_init()
{
  WDTCTL = WDTPW+WDTHOLD;                // Stop WDT

  //set CPU clock
  if (CALBC1_16MHZ ==0xFF || CALDCO_16MHZ == 0xFF)
  {
while(1);
  }
  BCSCTL1 = CALBC1_16MHZ;                   // Set DCO to 16MHz
  DCOCTL = CALDCO_16MHZ;

  //set UART clock
  BCSCTL1 &= ~XT2OFF;                      // Activate XT2 high freq xtal
  BCSCTL3 |= XT2S_2;                      // 16MHz crystal or resonator
  BCSCTL2 |= SELS;                      // SMCLK = XT2 HF XTAL (safe)
}
void IO_init()
{
  P2DIR |= 0x20;                         // Set P2.5(RESET) to output direction
  P2DIR |= 0x40;                         // Set P2.6(START) to output direction
  P3DIR |= 0x01;                         // Set P3.0(CS) to output direction
  P2OUT &=~0x20;
  delay(1000);
  P2OUT |= 0x20;                         //RESET=1
  P2OUT |= 0x40;                         //START=1
  P3OUT &=~0x01;                         //CS=0

  P2DIR |= 0x04;                         //Set P2.2 to output direction,this is LED
}
void UARTA1_init()
{
  P3SEL |= 0x0C0;                         // Use P3.6/P3.7 for USCI_A1
  UCA1CTL1 |= UCSSEL_2;          // 01000001,ACLK,32.768k
  UCA1BR0 = 139;                            // 16000000/115200=139;
  UCA1BR1 = 0;
  //UCA1CTL0=0x00;                //00000000,8bits,no parity,1 stop bit,UART
  UCA1CTL1 &= ~UCSWRST;                   // Resume operation
}
void UARTA1_send(unsigned char TxByte)
{
while (!(UC1IFG & UCA1TXIFG));          // USCI_A1 TX buffer ready?
UCA1TXBUF = TxByte;                   // TX and Rx character
}
void SPIB0_init()
{
  P3SEL |= 0x0E;                         // P3.3,2 USCI_B0 option select
  UCB0CTL0 |= UCMSB + UCMST + UCSYNC;    // 3-pin, 8-bit SPI mstr, MSB 1st
  UCB0CTL1 |= UCSSEL_2;                   // SMCLK
  UCB0BR0 = 0x08;
  UCB0BR1 = 0;
  UCB0CTL1 &= ~UCSWRST;                   // **Initialize USCI state machine**
}
void ADS1246_init()
{
  delay(1000000);
  UCB0TXBUF=0x43;       //写SYS0寄存器
  delay(1000000);
  UCB0TXBUF=0x00;       //待设置的寄存器数量为1
  delay(1000000);
  UCB0TXBUF=0x08;       //内部增益为1，采样率为1k
  delay(1000000);
}
void P27interrupt_init()
{
  P2IE |= 0x80;                            // P2.7 interrupt enabled
  P2IES |= 0x80;                         // P2.7 Hi/lo edge
  P2IFG &= ~0x80;                         // P2.7 IFG cleared
  __bis_SR_register(GIE);    //interrupt enable
}
void main(void)
{
  clock_init();
  IO_init();
  UARTA1_init();
  SPIB0_init();
  ADS1246_init();
  P27interrupt_init();
  while(1)
  {
while(P2IFG&0x80)
{
   UCB0TXBUF = 0xFF;
   while (!(IFG2 & UCB0RXIFG));          // RXBUF ready?, data received??
   data = UCB0RXBUF;
   UARTA1_send(data);                   //MSB

   UCB0TXBUF = 0xFF;
   while (!(IFG2 & UCB0RXIFG));          // RXBUF ready?, data received??
   data = UCB0RXBUF;
   UARTA1_send(data);                   //Mid-Byte

   UCB0TXBUF = 0xFF;
   while (!(IFG2 & UCB0RXIFG));          // RXBUF ready?, data received??
   data = UCB0RXBUF;
   UARTA1_send(data);                   //LSB

   P2IFG &= ~0x80;                      // P2.7 IFG cleared
}
  }
}