msp430中I/O口的设置

只看该作者 · 2008-7-22 14:45

如果I/O口设为第二功能,还要设为输入输出吗?例如P1SEL=0XFF;P1还要设为输出吗

只看该作者 · 2008-7-22 16:19

哦

只看该作者 · 2008-7-22 19:06

#include  <msp430x14x.h>

void main(void)
{
  volatile unsigned int i;

  WDTCTL = WDTPW + WDTHOLD;                 // Stop WDT
  P3SEL |= 0x30;                            // P3.4,5 = USART0 TXD/RXD
  BCSCTL1 |= XTS;                           // ACLK= LFXT1= HF XTAL

  do
  {
  IFG1 &= ~OFIFG;                           // Clear OSCFault flag
  for (i = 0xFF; i > 0; i--);               // Time for flag to set
  }
  while ((IFG1 & OFIFG));                   // OSCFault flag still set?

  BCSCTL2 |= SELM_3;                        // MCLK = LFXT1 (safe)
  ME1 |= UTXE0 + URXE0;                     // Enable USART0 TXD/RXD
  UCTL0 |= CHAR;                            // 8-bit character
  UTCTL0 |= SSEL0;                          // UCLK= ACLK
  UBR00 = 0x45;                             // 8MHz 115200
  UBR10 = 0x00;                             // 8MHz 115200
  UMCTL0 = 0x00;                            // 8MHz 115200 modulation
  UCTL0 &= ~SWRST;                          // Initialize USART state machine
  IE1 |= URXIE0;                            // Enable USART0 RX interrupt

  _BIS_SR(LPM0_bits + GIE);                 // Enter LPM0 w/ interrupt
}

#pragma vector=UART0RX_VECTOR
__interrupt void usart0_rx (void)
{
  while (!(IFG1 & UTXIFG0));                // USART0 TX buffer ready?
  TXBUF0 = RXBUF0;                          // RXBUF0 to TXBUF0
}
这是TI官方网站上的程序,它的p3.4就没设为输出,难道TI提供的程序错了?