Radio notification init problem

[codezork]

I am trying the tutorial Radio Notification and was following the patch from Ble_radio_notification wont compile. The radio notification init comes right after the ble enabling:

// Initialize the SoftDevice handler module.
SOFTDEVICE_HANDLER_INIT(&clock_lf_cfg, NULL);
APP_ERROR_CHECK(ble_radio_notification_init(APP_IRQ_PRIORITY_LOW, 
                                            NRF_RADIO_NOTIFICATION_DISTANCE_800US, 
                                            ble_radio_notification_evt_handler));

Inside ble_radio_notification_init the function sd_nvic_EnableIRQ(SWI1_IRQn) fails. The check inside this function:

  if (!__sd_nvic_is_app_accessible_priority(NVIC_GetPriority(IRQn)))
  {
    return NRF_ERROR_SOC_NVIC_INTERRUPT_PRIORITY_NOT_ALLOWED;
  }

gets a strange value of 0x301 from NVIC_GetPriority(IRQn) which is recognized wrong in the following test. How does it come to such a value when processing:

((uint32_t)((NVIC->IP[ _IP_IDX(IRQn)] >> _BIT_SHIFT(IRQn) ) >> (8 - __NVIC_PRIO_BITS)));

Could it be some kind of environment setting which is wrong?

[Susheel Nuguru]

for me in core_cm4.h file it shows like below

There is no _BIT_SHIFT here. Are you having correct CMSIS files

[codezork]

Thank you for your quick answer. I forgot to say that I am working on a nrf51422 which is Cortex-M0 based. And my core_cm0.h file looks like this:

__STATIC_INLINE uint32_t NVIC_GetPriority(IRQn_Type IRQn)
{

  if(IRQn < 0) {
    return((uint32_t)((SCB->SHP[_SHP_IDX(IRQn)] >> _BIT_SHIFT(IRQn) ) >> (8 - __NVIC_PRIO_BITS)));  } /* get priority for Cortex-M0 system interrupts */
  else {
    return((uint32_t)((NVIC->IP[ _IP_IDX(IRQn)] >> _BIT_SHIFT(IRQn) ) >> (8 - __NVIC_PRIO_BITS)));  } /* get priority for device specific interrupts  */
}

[codezork]

IMHO you must change nrf_nvic.h for SDK11 to:

static inline uint32_t sd_nvic_EnableIRQ(IRQn_Type IRQn)
{
  if (!__sd_nvic_app_accessible_irq(IRQn))
  {
    return NRF_ERROR_SOC_NVIC_INTERRUPT_NOT_AVAILABLE;
  }
  if (!__sd_nvic_is_app_accessible_priority(NVIC_GetPriority(IRQn)&0xF))
  {
    return NRF_ERROR_SOC_NVIC_INTERRUPT_PRIORITY_NOT_ALLOWED;
  }

  if (nrf_nvic_state.__cr_flag)
  {
    nrf_nvic_state.__irq_masks[(uint32_t)((int32_t)IRQn) >> 5] |= (uint32_t)(1 << ((uint32_t)((int32_t)IRQn) & (uint32_t)0x1F));
  }
  else
  {
    NVIC_EnableIRQ(IRQn);
  }
  return NRF_SUCCESS;
}

After this change ble_radio_notification.c works properly on a nrf51.

[Susheel Nuguru]

There was a bug in the older versions of CMSIS core_cm0.h which was fixed (i dont know which version it was fixed, download the latest)

The new implemenation shows that masking is done correctly with 0XFF (not 0XF which you opted in your code) below is the code from newer core_cm0.h file

__STATIC_INLINE uint32_t NVIC_GetPriority(IRQn_Type IRQn)
{

  if ((int32_t)(IRQn) < 0)
  {
    return((uint32_t)(((SCB->SHP[_SHP_IDX(IRQn)] >> _BIT_SHIFT(IRQn) ) & (uint32_t)0xFFUL) >> (8U - __NVIC_PRIO_BITS)));
  }
  else
  {
    return((uint32_t)(((NVIC->IP[ _IP_IDX(IRQn)] >> _BIT_SHIFT(IRQn) ) & (uint32_t)0xFFUL) >> (8U - __NVIC_PRIO_BITS)));
  }
}

[codezork]

Thank you for clarifying this.