include  <msp430g2231.h>
unsigned int flag = 0;void main(){    WDTCTL = WDTPW +WDTHOLD;   //STOP WDT   // FLL_CTL0 |= XCAP14PF;   //匹配14PF的负载电容    P1SEL &= ~BIT5;          P1DIR |= BIT5;     TACTL = TASSEL1 + TACLR ;     TACCTL0 = CCIE;    TACCR0 = 1748;    TACTL |= MC0;    _EINT();    while (1) {    LPM0;    }}
# pragma vector = TIMERA0_VECTOR__interrupt void TimerA0_ISR(void){    P1OUT ^= BIT5;    flag++;}
我用flag作为标志，发现并没有进入中断，为什么啊？哪里错了？ 此帖出自小平头技术问答