Hi,
I have nRF52840 DK and am using nRF5_SDK_17.0.2_d674dde.
I am not using SoftDevice, and Zephyr RTOS.
I have a simple program and using RTC0 timer. My code snippet:
const uint32_t m_dwPreScales[10]={
4095,1365,819,585,455, 315,273,195,151,105};
const uint32_t m_dwRTCsCC[10]={
8, 24, 40, 56, 72, 104,120,168,216,312};
void rtc_initialize(void) {
uint32_t err_code;
k++;
if (k>=9) k=0;
//k=5;
//=======================================================
NRF_RTC0->TASKS_STOP= 1;
NVIC_ClearPendingIRQ(RTC0_IRQn);
NVIC_DisableIRQ(RTC0_IRQn);
NRF_RTC0->EVTENCLR = RTC_INT_MASK;
NRF_RTC0->INTENCLR = RTC_INT_MASK;
//=======================================================
volatile uint32_t prescaler= m_dwPreScales[k];
volatile uint32_t duration_ticks= m_dwRTCsCC[k];
NRF_RTC0->TASKS_CLEAR= 1;
//NRF_RTC0->TASKS_TRIGOVRFLW= 1;
NRF_RTC0->PRESCALER = prescaler;
NRF_RTC0->CC[0] = 3;
NRF_RTC0->CC[1] = duration_ticks;
NRF_RTC0->INTENSET = RTC_CHANNEL_INT_MASK(0);
NRF_RTC0->EVTENSET = RTC_CHANNEL_INT_MASK(0);
NRF_RTC0->INTENSET = RTC_CHANNEL_INT_MASK(1);
NRF_RTC0->EVTENSET = RTC_CHANNEL_INT_MASK(1);
NRF_RTC0->EVTENSET = NRF_RTC_INT_TICK_MASK;
NVIC_SetPriority(RTC0_IRQn, 2);
NVIC_EnableIRQ(RTC0_IRQn);
NRF_RTC0->TASKS_START=1U;
//======================================================
}
void RTC0_IRQHandler(void)
{
if(NRF_RTC0->EVENTS_TICK){
NRF_RTC0->EVENTS_TICK = 0;
}
if ((NRF_RTC0->EVENTS_COMPARE[0] != 0) )
{
NRF_RTC0->EVENTS_COMPARE[0] = 0;
nrf_gpio_pin_toggle(LED1_PIN);
}
if ((NRF_RTC0->EVENTS_COMPARE[1] != 0))
{
NRF_RTC0->EVENTS_COMPARE[1] = 0;
nrf_gpio_pin_toggle(LED1_PIN);
rtc_initialize();
//NRF_RTC0->TASKS_START =1U;
}
if(NRF_RTC0->EVENTS_OVRFLW){
NRF_RTC0->EVENTS_OVRFLW = 0;
}
return ;
}
The code runs OK, the period is 1 second for any fixed k, which basically prescaler and CC[1]. Only CC[0] and CC[1] are enabled. For any fixed k with a pair of prescaler and CC1, with event period is 1 second.
But If I change k++, everytime re-initialization, the period becomes 1s, 2s, 3s,4s, 5s, ... (may not exactly).
Could you please help me take a code review for apparent mistakes?
Thank you,
David
