MSP430 G2553 Timer_A主定时器外部时钟输入

#include <msp430.h>

int main(void)
{
  WDTCTL = WDTPW | WDTHOLD;                 // Stop WDT

  // Configure GPIO
  P1DIR |= BIT6;
  P1OUT = 0;

  P1SEL |= BIT0;                           // P1.0 selected as TA0CLK

  // Configure Timer_A
  TA0CTL = TASSEL_0 | MC_2 | TACLR | TAIE;  // ACLK, count mode, clear TAR, enable interrupt
  TA0R = 0xFFFF - 10;                       // Offset until TAR overflow
  __bis_SR_register(LPM3_bits | GIE);       // Enter LPM3, enable interrupts

  while (1)
  {

  }
}

// Timer0_A3 Interrupt Vector (TAIV) handler
#if defined(__TI_COMPILER_VERSION__) || defined(__IAR_SYSTEMS_ICC__)
#pragma vector=TIMER0_A1_VECTOR
__interrupt void TIMER0_A1_ISR(void)
#elif defined(__GNUC__)
void __attribute__ ((interrupt(TIMER0_A1_VECTOR))) TIMER0_A1_ISR (void)
#else
#error Compiler not supported!
#endif
{
  switch(__even_in_range(TA0IV,TA0IV_TAIFG))
  {
      case TA0IV_NONE:
          break;                             // No interrupt
      case TA0IV_TACCR1:
          break;                             // CCR1 not used
      case TA0IV_TACCR2:
          break;                             // CCR2 not used
      case TA0IV_TAIFG:                      // overflow
    	  TA0R = 0xFFFF - 10;
    	  P1OUT ^= BIT6;
          break;
      default:
          break;
  }
}