nRF52810 TIMER counts very slow

[iTXS]

Hi, I have problem with timer in nrf52810. My TIMER2 counts very slow. I declared it as NRF_DRV_TIMER_INSTANCE(2); and config struct is:

.frequency = NRF_TIMER_FREQ_16MHz,
.mode = NRF_TIMER_MODE_TIMER,
.bit_width = NRF_TIMER_BIT_WIDTH_32,
.interrupt_priority = TIMER_DEFAULT_CONFIG_IRQ_PRIORITY,
.p_context = NULL

and

nrf_drv_timer_init(&timer2, &timer2_cfg, TimerHandler);
nrf_drv_timer_extended_compare(&timer2,
NRF_TIMER_CC_CHANNEL0,
1,
NRF_TIMER_SHORT_COMPARE0_CLEAR_MASK,
true);

and in interrupt handler

void TimerHandler(nrf_timer_event_t event_type, void * p_context)
{
   if ((var++ % 1000) == 0)
       nrf_gpio_pin_toggle(6);
}

Frequency which i see in oscilloscope is 46.72 Hz. BLE and RTC is turned on. 

But frequency should be 8 kHz. My SDK is nRF5 SDK v14.2.0, softdevice s112. TIMER_DEFAULT_CONFIG_IRQ_PRIORITY is 3 for this example.

[MartinBL]

Hi,

Although the blinking frequency should only be 8 kHz you are actually trying to process an interrupt 8 million(!) times per second. The CPU is simply not that fast. If you are using a Softdevice it will also have priority over your interrupt, Interrupt priority levels. Try to slow down the interrupt frequency and see if that helps. 

[iTXS]

But why TIMER allow these high frequencies?

[MartinBL]

High frequency allows high "resolution". You can also use the timer with PPI and GPIOTE to toggle a GPIO at up to 8 MHz if you want.