RTC time counter doesn't work on K64

[Mota]

Hi guys,

I'm working with a RTC peripheral on K64 with external 32,768Khz clock and the time counter doesn't seem to work. In other words, the RTC->TSR content stay the same. I verified on the XTAL output and the oscillator is working correctly. 

There is my init :

rtc_config_t RTC_config = {
.wakeupSelect = false,
.updateMode = false,
.supervisorAccess = false,
.compensationInterval = 0x0U,
.compensationTime = 0x0U
};

dateTime_st.u16Year = 2021;
dateTime_st.u8Month = 11;
dateTime_st.u8Day = 24;
dateTime_st.u8Hour = 8;
dateTime_st.u8Min = 54;
dateTime_st.u8Sec = 00;

/* RTC initialization */
RTC_Init(RTC, &RTC_config);

/* Select RTC clock source */
RTC_SetClockSource(RTC); // Same as : RTC->CR |= RTC_CR_OSCE_MASK;

/* Stop RTC timer */
RTC_StopTimer(RTC); // Same as : RTC->SR |= ~RTC_SR_TCE_MASK;

/* Date and time initialization */
RTC_SetDatetime(RTC, (rtc_datetime_t *) &dateTime_st);

/* Start RTC timer */
RTC_StartTimer(RTC); // Same as : RTC->SR |= RTC_SR_TCE_MASK;

My clock sources and diagram configuration :

Any idea ?

Thank you by advance.

Best regards.

Mota

[Mota]

Hi @nxf77486,

Ok I'll research in the RTC configuration first. Thank you for these examples. I let you know.

Thank you.

Regards,

Mota

[nxf77486]

Hello @Mota ,

Thank you for your information I understand that your HW 32kHZ crystal is fine. Can you please check the RTC oscillator initialization that something has not been missing like the RTC_CR_OSCE bit (check if this is being set 1).

I also due recommend to try one of the SDK examples for the RTC.

[Mota]

Hi @nxf77486,

Thank you for your answer. RTC_CR_OSCE is well set to "1". I verified SR[TOF] and SR[TIF] bits and they are set to "0". Then the time counter should increment this value but it's not the case. The RTC_TSR counter stay always at the same value which is set at the beginning by RTC_SetDatetime().

There is the setup of my oscillator (It’s automaticaly genereted when I setup the clock sources) :

{
  /* RTC clock gate enable */
  CLOCK_EnableClock(kCLOCK_Rtc0);
  if ((RTC->CR & RTC_CR_OSCE_MASK) == 0u) { /* Only if the Rtc oscillator is not already enabled */
    /* Set the specified capacitor configuration for the RTC oscillator */
    RTC_SetOscCapLoad(RTC, capLoad);
    /* Enable the RTC 32KHz oscillator */
    RTC->CR |= RTC_CR_OSCE_MASK;
  }
  /* Output to other peripherals */
  if (enableOutPeriph) {
    RTC->CR &= ~RTC_CR_CLKO_MASK;
  }
  else {
    RTC->CR |= RTC_CR_CLKO_MASK;
  }
  /* Set the XTAL32/RTC_CLKIN frequency based on board setting. */
  CLOCK_SetXtal32Freq(BOARD_XTAL32K_CLK_HZ);
  /* Set RTC_TSR if there is fault value in RTC */
  if (RTC->SR & RTC_SR_TIF_MASK) {
    RTC -> TSR = RTC -> TSR;
  }
  /* RTC clock gate disable */
  CLOCK_DisableClock(kCLOCK_Rtc0);
}

And it’s call in my main() by :

BOARD_InitBootClocks();

You will find below my RTC hardware configuration, I use VBAT too :

I don’t have FRDM-K64 board to test these kind of examples and I’m working with a MK64FX512xxx12 instead of MK64FN1M0xxx12..

Thank you.

Regards,

Mota

[nxf77486]

Hello @Mota ,

I believe this could still be related with the RTC configuration.

I understand you are using a MK64FX512xxx12, but the RTC examples for the FRDM-K64 still a good reference for your project they still the same module.

SDK FRDM-K64

FRDM-K64F