LP-EM-CC2340R5: RTS Timer: Waking up from standby by RTC timer

    /* Set constraint to disallow standby while running */
    Power_setConstraint(PowerLPF3_DISALLOW_STANDBY);

#define SYSTIM_PERIOD_MS 2000
#define SYSTIM_FREQ 32768  // Frequency 32.768 kHz for timer SYSTIM
HwiP_Struct systimHwi;

// Interrupt handler for SYSTIM
void systimInterruptHandler(uintptr_t arg) {
    // Check if the interrupt from channel 0 worked
    if (HWREG(SYSTIM_BASE + SYSTIM_O_OUT) & SYSTIM_OUT_OUT0) {
        // Clear the interrupt
        HWREG(SYSTIM_BASE + SYSTIM_O_OUT) |= SYSTIM_OUT_OUT0;  // Clear the event

        // Timer has expired, executing your code
        // For example, stopping a timer
        HWREG(SYSTIM_BASE + SYSTIM_O_CH0CFG) &= ~(1 << 1);  // Disable the timer

        GPIO_toggle(CONFIG_GPIO_LED_RED);
    }
}

void systimTimerInit(void) {
    uint32_t timer_value =
        SYSTIM_PERIOD_MS *
        (SYSTIM_FREQ / 1000);  // Conversion to the number of clocks (timer clocks)

    // Setting the timer period (value in clocks)
    HWREG(SYSTIM_BASE + SYSTIM_O_CH0CC) = timer_value;

    // Configuration of the SYSTIM channel to work in countdown mode
    // Enable channel, timer in countdown mode (Count-down)
    HWREG(SYSTIM_BASE + SYSTIM_O_CH0CFG) =
        (SYSTIM_CH0CFG_MODE_CAPT |  // Timer mode: Capture
         SYSTIM_CH0CFG_INP_RISE |   // Capture on the rising edge (you can choose FALL or BOTH)
         SYSTIM_CH0CFG_REARM_DIS |  // Disabling continuous capture (One-shot mode)
         SYSTIM_CH0CFG_RES_US);  // 1 µs resolution (can be changed to SYSTIM_CH0CFG_RES_NS for 250
                                 // ns)

    // Initialize interrupt for SYSTIM channel 0
    HwiP_construct(&systimHwi, INT_CPUIRQ0, systimInterruptHandler, NULL);
    HwiP_enableInterrupt(INT_CPUIRQ0);  // Enable interrupt

    // Start timer
    HWREG(SYSTIM_BASE + SYSTIM_O_CH0CFG) |=
        SYSTIM_CH0CFG_MODE_CAPT;  // Enable the timer channel to run

    // Reset timer event
    HWREG(SYSTIM_BASE + SYSTIM_O_OUT) &= ~SYSTIM_OUT_OUT0;
    // Clear channel 0 event
}

#define RTC_PERIOD_MS 3000
#define RTC_FREQ 32768  // Frequency 32.768 kHz for timer SYSTIM
HwiP_Struct rtcHwi;

void rtcInterruptHandler(uintptr_t arg) {
    if (HWREG(RTC_BASE + RTC_O_RIS) & RTC_RIS_EV0) {
        HWREG(RTC_BASE + RTC_O_ICLR) |= RTC_RIS_EV0;

        GPIO_toggle(CONFIG_GPIO_LED_GREEN);
        HWREG(RTC_BASE + RTC_O_CTL) |= RTC_CTL_RST;
    }
}

void rtcInit(void) {
    uint32_t rtc_interval = RTC_PERIOD_MS * (RTC_FREQ / 1000);

    HWREG(RTC_BASE + RTC_O_CH0CC8U) = rtc_interval;

    HWREG(RTC_BASE + RTC_O_IMASK) |= RTC_RIS_EV0;


    HwiP_construct(&rtcHwi, INT_CPUIRQ0, rtcInterruptHandler, NULL);
    HwiP_enableInterrupt(INT_CPUIRQ0);

    HWREG(RTC_BASE + RTC_O_CTL) |= RTC_CTL_RST;
    HWREG(RTC_BASE + RTC_O_CTL) &= ~RTC_CTL_RST;
}

Thanks for the answer, now i use 31.25 kHz