Use timer2 to generate 1K Hz square waveform, but can not get a continuously 1K Hz square waveform

Question

Hi

I want a 1K Hz square waveform to drive a peripheral device, but I can not get a continuously square waveform on GPIO 19, pls have a look at the picture I attached, the following is the timer initialization and interrupt routine, pls help check why this happened, thanks.

////////////////////////////////////////////////////////////////////////////Timer2 init static void timer2_init (void) { NRF_TIMER2->TASKS_STOP = 1; // Create an Event-Task shortcut to clear TIMER0 on COMPARE[0] event NRF_TIMER2->MODE = TIMER_MODE_MODE_Timer; NRF_TIMER2->BITMODE = TIMER_BITMODE_BITMODE_16Bit; NRF_TIMER2->PRESCALER = timer2_prescaler_set; // timer2_prescaler_set = 4

NRF_TIMER2->TASKS_CLEAR = 1;               	// clear the task first to be usable for later

NRF_TIMER2->CC[0] = timer2_interval;   //timer2_interval = 500			

NRF_TIMER2->INTENSET    = TIMER_INTENSET_COMPARE0_Enabled << TIMER_INTENSET_COMPARE0_Pos;
/* Create an Event-Task shortcut to clear TIMER1 on COMPARE[0] event. */

// NRF_TIMER2->SHORTS = (TIMER_SHORTS_COMPARE1_CLEAR_Enabled << TIMER_SHORTS_COMPARE1_CLEAR_Pos);

sd_nvic_SetPriority (TIMER2_IRQn, APP_IRQ_PRIORITY_LOW);		// Setzt die Prioroität auf HIGH

sd_nvic_EnableIRQ (TIMER2_IRQn); // Aktiviert den Interrupt

NRF_TIMER2->TASKS_START = 1;

}

//////////////////////////////////////////////////////////////////////////////////////////////////////// void TIMER2_IRQHandler(void) { uint16_t i;

if ((NRF_TIMER2->EVENTS_COMPARE[0] != 0) && \
    ((NRF_TIMER2->INTENSET & TIMER_INTENSET_COMPARE0_Msk) != 0))
{
		NRF_TIMER2->EVENTS_COMPARE[0] = 0;
		NRF_TIMER2->CC[0] += timer2_interval;
									
		nrf_gpio_pin_toggle(19);
}

}