All notable changes to this project are documented in this file.

nRF Connect SDK v1.6.1

No changes in this release.

nRF Connect SDK v1.6.0


  • Added an API to set and get a flag that determines whether to apply the DEVICE-CONFIG-254. The API user shall set the flag to desired value with mpsl_fem_device_config_254_shall_apply_set(). The protocol stacks’ responsibility is to check the flag value using mpsl_fem_device_config_254_shall_apply_get() and apply the configuration when the flag value is true.

  • Added support for the nRF5340 device, which was previously only supported for evaluation purposes. (DRGN-8639)


  • Reserved TIMER1 for use by MPSL on nRF5340 (DRGN-15721).

Bug fixes

nRF Connect SDK v1.5.0


  • Added a new signal to the MPSL timeslot: MPSL_TIMESLOT_SIGNAL_OVERSTAYED. This signal is given to the application when a timeslot session is closed too late. (DRGN-14677)

  • Added a new clock configuration option skip_wait_lfclk_started in mpsl_clock_lfclk_cfg_t, which does not wait for the start of Low Frequency Clock. (DRGN-14204)

  • Added macro MPSL_RESERVED_PPI_CHANNELS for a bit mask of (D)PPI channels reserved by MPSL (DRGN-13356).

Bug fixes

  • Fixed an issue where Low Frequency Clock was configured incorrectly when the source configuration signal was set to either External Full swing or External Low swing. (DRGN-15064)

  • Fixed an issue where MPSL waited for Low Frequency Clock to start even though it was configured not wait for it. (DRGN-15176)

nRF Connect SDK v1.4.0


  • Changed the timeslot implementation to support up to 8 concurrent sessions (DRGN-13952). It is now necessary to supply a timeslot context configuration using mpsl_timeslot_session_count_set(). All timeslot APIs now take a session_id as input. The session id is retrieved from mpsl_timeslot_session_open().

  • Added an API to use Front-End Modules, like the nRF21540 GPIO or a simple GPIO, with the protocols and an API to configure them using the application. Only the nRF52 Series is supported.

Bug fixes

  • Fixed an issue where the high frequency clock and TIMER0 were not turned off during idle periods shorter than 9 ms (DRGN-14152). This increased the average power consumption. Such a case could occur when running a Bluetooth LE connection with a connection interval of 7.5 ms.

Known Issues and limitations

See the Known issues page in nRF Connect SDK for the list of known issues and limitations for this release.

nRF Connect SDK v1.3.0


  • Added API for fetching build revision information.

  • Added API to set a TX Power envelope. Protocols using MPSL will limit their TX power to a value equal to, or lower than, the provided value.

  • Added support for using a low-swing and full-swing LF clock.

  • The support for integrating an 802.15.4 driver is now improved.



  • On nRF53, the fix for Errata 16 is now applied.

  • The scheduling overhead of a timeslot event is reduced.

Bug fixes

  • Fixed an issue on nRF53 where an assert could occur when using a timeslot.

nRF Connect SDK v1.2.0


  • Added a library version with preliminary support for the nRF5340 device. The feature set is the same as in the MPSL library for nRF52. The following library has been added:



  • Removed _nrf52 from the MPSL library file names.

  • Version numbers have been removed from the libraries.

  • It is no longer allowed to call mpsl_init() if MPSL is already initialized.

  • Clock configuration parameters for any stack that uses MPSL must be provided in mpsl_clock_lfclk_cfg_t to mpsl_init(). This now also involves clock accuracy.

  • Clock accuracy must be specified in parts per million (ppm).

  • Renamed MPSL clock API for high and low frequency clock.

MPSL 0.5.0-1.prealpha

Initial release.


  • Added the following MPSL library build variants:

    • hard-float/libmpsl_nrf52.a

    • soft-float/libmpsl_nrf52.a

    • softfp-float/libmpsl_nrf52.a