nrf5-calendar-example SOFTDEVICE: INVALID MEMORY ACCESS

[snowuyl]

I try to integrate https://github.com/NordicPlayground/nrf5-calendar-example into Keil project. But the following error messages shown when accessing NRF_CLOCK.

error messages

nrf5-calendar-example SOFTDEVICE: INVALID MEMORY ACCESS

source code

int main(void) {
    _initVariables();
    

    // Initialize.
    log_init(); // Power_saving
    uart_init(); // Power_saving
    //_showInfo();
    fstorageInit();
    batteryVoltageInit();
    timerInit();
    button_events_init();
    scheduler_init();
    power_management_init();
    ble_stack_init();
    gap_params_init();
    gatt_init();
    db_discovery_init();
    services_init();
    advertising_init();
    conn_params_init();
    timerPeriodStart();
    timerStart();
    

    //  SOFTDEVICE: INVALID MEMORY ACCESS occurred when running the following code
    NRF_CLOCK->EVENTS_HFCLKSTARTED = 0;
    NRF_CLOCK->TASKS_HFCLKSTART = 1;
    while(NRF_CLOCK->EVENTS_HFCLKSTARTED == 0);
    
     nrf_cal_init();
     nrf_cal_set_callback(calendar_updated, 4);

}

[Vidar Berg]

Hello,

The app does not have write access to the CLOCK peripheral when the Softdevice is enabled, hence the assert (See Hardware peripherals). Instead you have to access it via the provided Softdevice APIs such as sd_clock_hfclk_request().

However, it should not be necessary to start HF crystal oscillator for the calendar library, so my suggestion would be to simply not include this code:

    NRF_CLOCK->EVENTS_HFCLKSTARTED = 0;
    NRF_CLOCK->TASKS_HFCLKSTART = 1;
    while(NRF_CLOCK->EVENTS_HFCLKSTARTED == 0);

Best regards,

Vidar

[snowuyl]

Thanks for your reply! I have changed above code to the following code.

const ret_code_t errCode = sd_clock_hfclk_request();
    if (errCode != NRF_SUCCESS) {
        NRF_LOG_WARNING("sd_clock_hfclk_request() failed\n");
    }    

    uint32_t hfclkIsRunning = 0;

    while (!hfclkIsRunning) {
        APP_ERROR_CHECK(sd_clock_hfclk_is_running(&hfclkIsRunning) );
    }

Now it hangs at nrf_cal_init() as the following error messages.

<debug> app: nrf_cal_init() e
 0>
 0> <error> app: SOFTDEVICE: INVALID MEMORY ACCESS

void nrf_cal_init(void) {
    NRF_LOG_DEBUG("nrf_cal_init() e\n");
    // Select the 32 kHz crystal and start the 32 kHz clock
    NRF_CLOCK->LFCLKSRC = CLOCK_LFCLKSRC_SRC_Xtal << CLOCK_LFCLKSRC_SRC_Pos;
    NRF_CLOCK->EVENTS_LFCLKSTARTED = 0;
    NRF_CLOCK->TASKS_LFCLKSTART = 1;
    while(NRF_CLOCK->EVENTS_LFCLKSTARTED == 0);
    NRF_LOG_DEBUG("1\n");
    
    // Configure the RTC for 1 minute wakeup (default)
    CAL_RTC->PRESCALER = 0xFFF;
    CAL_RTC->EVTENSET = RTC_EVTENSET_COMPARE0_Msk;
    CAL_RTC->INTENSET = RTC_INTENSET_COMPARE0_Msk;
    CAL_RTC->CC[0] = m_rtc_increment * 8;
    CAL_RTC->TASKS_START = 1;

}

[snowuyl]

Do you have any suggestion about how to change NRF_CLOCK and CAL_RTC related code to Softdevice APIs?

[Vidar Berg]

You don't need to start the LF clock either as the Softdevice does it when you enable it. So uou can remove this from cal_init():

    NRF_CLOCK->LFCLKSRC = CLOCK_LFCLKSRC_SRC_Xtal << CLOCK_LFCLKSRC_SRC_Pos;
    NRF_CLOCK->EVENTS_LFCLKSTARTED = 0;
    NRF_CLOCK->TASKS_LFCLKSTART = 1;
    while(NRF_CLOCK->EVENTS_LFCLKSTARTED == 0);

[snowuyl]

I have removed NRF_CLOCK related code from nrf_cal_init().Do you have any suggestion about how to change CAL_RTC related code to Softdevice APIs?

void nrf_cal_init(void) {
    NRF_LOG_DEBUG("nrf_cal_init() e\n");
    
    // Configure the RTC for 1 minute wakeup (default)
    CAL_RTC->PRESCALER = 0xFFF;
    CAL_RTC->EVTENSET = RTC_EVTENSET_COMPARE0_Msk;
    CAL_RTC->INTENSET = RTC_INTENSET_COMPARE0_Msk;
    CAL_RTC->CC[0] = m_rtc_increment * 8;
    CAL_RTC->TASKS_START = 1;

}

[Vidar Berg]

Yes, RTC0 is reserved to the Softdevice as well, so you need to select another RTC instance.

In nrf_calendar.h, change:

// Change the following defines to change the RTC timer used or the interrupt priority
#define CAL_RTC                 NRF_RTC0
#define CAL_RTC_IRQn            RTC0_IRQn
#define CAL_RTC_IRQHandler      RTC0_IRQHandler
#define CAL_RTC_IRQ_Priority    3

To:

// Change the following defines to change the RTC timer used or the interrupt priority
#define CAL_RTC                 NRF_RTC2
#define CAL_RTC_IRQn            RTC2_IRQn
#define CAL_RTC_IRQHandler      RTC2_IRQHandler
#define CAL_RTC_IRQ_Priority    6