This is the documentation for the latest (main) development branch of Zephyr. If you are looking for the documentation of previous releases, use the drop-down menu on the left and select the desired version.

NRF54L15 simulated boards (BabbleSim)


To allow simulating nRF54L15 SOCs a Zephyr target boards is provided: the nrf54l15bsim/nrf54l15/cpuapp.

This uses BabbleSim to simulate the radio activity, and the POSIX architecture and the native simulator to run applications natively on the development system. This has the benefit of providing native code execution performance and easy debugging using native tools, but inherits its limitations.

Just like for the nrf54l15pdk target, the nrf54l15bsim/nrf54l15/cpuapp build target provides support for the application core, on the simulated nRF54L15 SOC.


This simulated target does not yet support targeting the cpuflpr core.


This target is experimental, and even though it includes models of the RADIO, it does not yet include models of the AAR, CCM or ECB peripherals, so the BLE and 802.15.4 stacks can only be run without encryption or privacy features so far.

This boards include models of some of the nRF54L15 SOC peripherals:

  • CLOCK (Clock control)

  • DPPI (Distributed Programmable Peripheral Interconnect)

  • EGU (Event Generator Unit)

  • FICR (Factory Information Configuration Registers)

  • GRTC (Global Real-time Counter)

  • PPIB (PPI Bridge)


  • RRAMC (Resistive RAM Controller)

  • RTC (Real Time Counter)

  • TEMP (Temperature sensor)


  • UICR (User Information Configuration Registers)

and will use the same drivers as the nrf54l15pdk targets for these. For more information on what is modeled to which level of detail, check the HW models implementation status.

Note that unlike a real nrf54l15 device, the nrf54l15bsim boards have unlimited RAM, and code does not occupy their RRAM.

Building for, and using this board

You can follow the instructions from the nrf52_bsim board. Simply change the board/target appropriately when building.

TrustZone, TF-M and other security considerations

ARM’s TrustZone is not modeled in this board. This means that:

  • There is no differentiation between secure and non secure execution states or bus accesses.

  • All RAM, flash and peripherals are in principle accessible from all SW. Peripherals with their own interconnect master ports can, in principle, access any other peripheral or RAM area.

  • There is no nrf54l15bsim/nrf54l15/cpuapp/ns board/build target, or possibility of mixing secure and non-secure images.

  • Currently there is no model of the SPU, and therefore neither RRAM, RAM areas or peripherals can be labeled as restricted for secure or non secure access.

  • TF-M cannot be used.

Note that the CRACEN peripheral is not modeled. The mbedTLS library can still be used but with a SW crypto backend.