Hardware peripherals

The SoftDevice requires certain hardware peripherals to function correctly. The availability of these hardware peripherals to the application depends on whether the SoftDevice is enabled or disabled.

The access types listed in the following table are used to categorize the availability of the hardware peripherals to the application. The application has access to most hardware peripherals. The exceptions are listed in Hardware peripherals with limited availability to the application.

Table 1. Hardware access type definitions
Access type Definition
Restricted The hardware peripheral is used by the SoftDevice and is outside the application sandbox. When the SoftDevice is enabled, it shall only be accessed through the SoftDevice API. Through this Application Programming Interface (API), the application has limited access.
Blocked The hardware peripheral is used by the SoftDevice and is outside the application sandbox.

The application has no access. Interrupts from blocked peripherals are forwarded to the SoftDevice by the MBR and are not available to the application, even inside a Radio Timeslot API timeslot.
Open The hardware peripheral is not used by the SoftDevice.

The application has full access.
Table 2. Hardware peripherals with limited availability to the application
Instance

Access

SoftDevice enabled

Access

SoftDevice disabled
CLOCK Restricted Open
POWER Restricted Open
RADIO Blocked1 Open
TIMER0 Blocked1 Open
RTC0 Blocked Open
TEMP Restricted Open
RNG Restricted Open
ECB Restricted Open
CCM Blocked2 Open
AAR Blocked2 Open
EGU1/SWI1/Radio Notification Restricted3 Open
EGU5/SWI5 Blocked Open
ACL Restricted Open
NVMC Restricted Open
MWU Restricted4 Open
FICR Blocked Blocked
UICR Restricted Open
NVIC Restricted5 Open
Note: Some of the peripherals in this table are not present on all devices. For a complete overview of the peripherals on a device, see the relevant product specification (Additional documentation).
Parent topic: System on Chip resource requirements
1 The peripheral is available to the application through the Radio Timeslot API. See Concurrent multiprotocol implementation using the Radio Timeslot API.
2 The peripheral is available to the application during a Radio Timeslot API timeslot. See Concurrent multiprotocol implementation using the Radio Timeslot API.
3 Blocked only when Radio Notification signal is enabled. See Application signals – software interrupts for SWI allocation.
4 See sections Memory isolation and runtime protection and Peripheral runtime protection for limitations on the use of MWU when the SoftDevice is enabled.
5 Not protected. For robust system function, the application program must comply with the restriction and use the SoftDevice NVIC API for configuration when the SoftDevice is enabled.