TimerA0 1秒定时 TIMER B 1 秒定时溢出中断
:MCLK = 2MHz DCOCLK
LFXT1 = 32768Hz   ACLK
***********************/

#include
unsigned int i;
unsigned int times,times_b;
unsigned int sec;

/***** 定时器A 初使化 *******/
void TimerA_Init(void)
{
TACTL = TASSEL_1 + ID0 + TACLR ; //ACLK=32768Hz ,清除tar ,2分频
CCTL0 = CCIE; //
CCR0 = 819;   // (1/32768)*819 =20 ms ??
TACTL |= MC0; //增计数   
}
/**** 定时器B 初使化 *****/
void TimerB_Init (void)
{
TBCTL = TBSSEL_1 + ID0 + TBCLR ; //ID_2 + ID1 +
TBCCTL0 = CCIE; // INTERRUPT ENABLE
TBCCR0 = 819; //
TBCTL |= MC0; 
}
/***** 秒测试 1秒响一下 ********/
void Sec_Beep(void)//beep every second 
{

    if(sec==1)
{
    sec = 0;
    P5OUT ^= 0x10;
} 

}
void main( void )
{
times = 20;
times_b = 20;
WDTCTL = WDTPW + WDTHOLD;
// SYstem clock
DCOCTL = 0x60;
BCSCTL1 = 0x86;//XT20FF ,XTS=0 LOW FREQ , RESEL=6 DCOCLK=2MHz
// XT2on, XTS DIVA.1 DIVA.0 XT5V RSEL.2 RSEL.1 RSEL.0
// 1     0   0       0         0     1      1       0
BCSCTL2 = 0x00; //MCLK = DCOCLK, DIVM=0, SMCLK=CCOCLK ,DIVS =0 
P1DIR |= 0x02; //p1.2 OUT
P5DIR |= 0x10; //P5.4 OUT

TimerA_Init(); //定时器初使化
TimerB_Init();

_EINT(); // interrupt enable
for(;;)
{
     _BIS_SR(LPM3_bits);
     _NOP();
}

}

/****** 定时器 A 中断 处理 ***********/
#pragma vector = TIMERA0_VECTOR
__interrupt void Timer_A (void)
{

times--;
if(times == 0)
{
    times = 20;
    sec=1;
    Sec_Beep();
}
}
/****** 定时器B 中断处理 ***********/
#pragma vector = TIMERB0_VECTOR
__interrupt void Timer_B0 (void)
{
        times_b--;
        if(times_b == 0)
        {
          times_b = 20; 
          P1OUT ^= 0x02;
        }
}