SPI收发问题[非中断]

什么型号的MCU？

这里给一段MSP430G2XX3的例程

#include "msp430g2553.h"

void main(void)
{
  WDTCTL = WDTPW + WDTHOLD;                 // Stop watchdog timer
  while (!(P1IN & BIT4));                   // If clock sig from mstr stays low,
                                            // it is not yet in SPI mode
 
  P1SEL = BIT1 + BIT2 + BIT4;
  P1SEL2 = BIT1 + BIT2 + BIT4;
  UCA0CTL1 = UCSWRST;                       // **Put state machine in reset**
  UCA0CTL0 |= UCCKPL + UCMSB + UCSYNC;      // 3-pin, 8-bit SPI master
  UCA0CTL1 &= ~UCSWRST;                     // **Initialize USCI state machine**

  while (!(IFG2 & UCA0TXIFG));              // USCI_A0 TX buffer ready?
 {

      UCA0TXBUF = UCA0RXBUF;

      IFG2 &=~UCA0TXIFG;

  }

}