请教定时器

我现在用库含税写一个定时器函数。需求：当计数值达到CCR0时产生中断，计数清零并重新计数，我的代码如下，并不能产生中断，帮忙检查一下是什么问题。

#include "msp430.h"
#include "driverlib.h"
uint16_t cnt;

void timer_init(void)
{
//Start timer in continuous mode sourced by ACLK
Timer_A_clearTimerInterrupt(TIMER_A1_BASE);

Timer_A_initUpModeParam param = {0};
param.clockSource = TIMER_A_CLOCKSOURCE_ACLK;
param.clockSourceDivider = TIMER_A_CLOCKSOURCE_DIVIDER_1;
param.timerPeriod = 1000;
param.timerInterruptEnable_TAIE = TIMER_A_TAIE_INTERRUPT_ENABLE;
param.captureCompareInterruptEnable_CCR0_CCIE = TIMER_A_CCIE_CCR0_INTERRUPT_ENABLE;
param.timerClear = TIMER_A_DO_CLEAR ;
param.startTimer = true;
Timer_A_initUpMode(TIMER_A0_BASE, &param);

// Timer_A_startCounter(TIMER_A1_BASE,
// TIMER_A_UP_MODE
// );
//Enter LPM0, enable interrupts
__bis_SR_register(LPM0_bits );

}

//******************************************************************************
//
//This is the TIMER1_A3 interrupt vector service routine.
//
//******************************************************************************
#pragma vector=TIMER0_A0_VECTOR
__interrupt void TIMER0_A0_ISR(void)
{
Timer_A_clearTimerInterrupt(TIMER_A0_BASE);
cnt++;
if(cnt%100 == 0 )
P3OUT ^= BIT3;
}