Can we call softdevice API before enabling softdevice ?

[Susheel Nuguru]

Please check the answer

[Susheel Nuguru]

Not all SDS versions are clear on this. So I decided to make this info visible.

softdevice API are all the function calls with names starting with prefix sd_which is exposed by softdevice.

Softdevice is enabled after successful call to sd_softdevice_enable

Softdevice is disabled after successful call to sd_softdevice_disable

All the calls from nrf_sdm.h (SoftDevice Manager) are available before and after enabling softdevice.

if you check nrf_soc.h file. There is an enum that looks like below

enum NRF_SOC_SVCS 
{
   XXXX,
   XXXX
}

All the defines inside this enum are intentionally made to look similar to the actual softdevice API call. for example enum value SD_NVIC_SYSTEMRESET is the SVC number for the softdevice call sd_nvic_systemreset()

Inside this enum, the SVC calls with numbers from

SOC_SVC_BASE
to 
SOC_SVC_BASE_NOT_AVAILABLE - 1

should be available even though softdevice is not enabled.

The api calls from

SOC_SVC_BASE_NOT_AVAILABLE to SVC_SOC_LAST -1

only work when softdevice is enabled else they will return

#define NRF_ERROR_SOFTDEVICE_NOT_ENABLED      (NRF_ERROR_BASE_NUM + 2)  ///< SoftDevice has not been enabled