CC2538的sleep timer无法进入中断

#define TIMERLOOP_THRESHOLD 0xffffff // 511 seconds @ 32768Hz clock
#define MINIMUM_COMPAREVALE_ADVANCE 5

// ========================== variable ========================================

typedef struct {
sctimer_cbt sctimer_cb;
} sctimer_vars_t;

sctimer_vars_t sctimer_vars;


// ========================== private =========================================

void sctimer_isr_internal(void);

// ========================== protocol =========================================

/**
\brief Initialization sctimer.
*/
void sctimer_init(void){
memset(&sctimer_vars, 0, sizeof(sctimer_vars_t));
//register sleep mode timer interrupt with ISR
IntRegister(INT_SMTIM, &sctimer_isr_internal);
//Enbale sleep mode interrupt from GPIO pin interrupt
GPIOIntWakeupEnable(GPIO_IWE_SM_TIMER);
//Disable sleep mode interrupt
IntDisable(INT_SMTIM);
IntPrioritySet(INT_SMTIM,3<<5);
}

void sctimer_set_callback(sctimer_cbt cb){
sctimer_vars.sctimer_cb = cb;
}

/**
\brief set compare interrupt
*/
void sctimer_setCompare(uint32_t
){
IntEnable(INT_SMTIM);
if (SleepModeTimerCountGet() - val < TIMERLOOP_THRESHOLD){
// the timer is already late, schedule the ISR right now manually
IntPendSet(INT_SMTIM);
} else {
if (val-SleepModeTimerCountGet()<MINIMUM_COMPAREVALE_ADVANCE){
// there is hardware limitation to schedule the timer within TIMERTHRESHOLD ticks
// schedule ISR right now manually
IntPendSet(INT_SMTIM);
} else {
// schedule the timer at val
SleepModeTimerCompareSet(val);
}
}
}

/**
\brief Return the current value of the timer's counter.

\returns The current value of the timer's counter.
*/
uint32_t sctimer_readCounter(void){
return SleepModeTimerCountGet();
}

void sctimer_enable(void){
IntEnable(INT_SMTIM);
}

void sctimer_disable(void){
IntDisable(INT_SMTIM);
}

// ========================== private =========================================

void sctimer_isr_internal(void){
debugpins_isr_set();
if (sctimer_vars.sctimer_cb!=NULL) {
IntPendClear(INT_SMTIM);
sctimer_vars.sctimer_cb();
debugpins_isr_clr();
}
debugpins_isr_clr();
}