.. _lib_bt_ll_acs_nrf53_readme:

LE Audio controller for nRF5340
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The LE Audio controller for nRF5340 is a link layer controller for the nRF5340 network core and is meant to be used with LE Audio applications.

This controller is compatible with the HCI RPMsg driver provided by the |NCS| Bluetooth® :ref:`bt_hci_drivers` core.
When the communication between the application and the network core on a device is handled by the HCI RPMsg driver, this link layer controller can be used to handle time critical low level communication and the radio.

Configuration
*************

The controller can be enabled with the :Kconfig:option:`CONFIG_BT_LL_ACS_NRF53` set to ``y``.

The controller has the following methods of configuration:

* Standard Host-Controller Interface (HCI) commands
* Vendor-Specific commands (VSC)

These are listed in :file:`ble_hci_vsc.h`.
See the :ref:`lib_bt_ll_acs_nrf53_api` for more information.

Usage
*****

This controller is provided as a HEX file and includes the LE Audio Controller Subsystem for nRF53.
Check the license file in the :file:`/bin` directory for usage conditions.

When using the file, the controller is programmed to the network core of nRF5340.
Configurations and calls are handled through standard HCI and VSC.

Samples using the library
*************************

The :ref:`nrf53_audio_app` application uses the controller.

Files
*****

The network core for both gateway and headsets of the :ref:`nrf53_audio_app` is programmed with the precompiled Bluetooth Low Energy Controller binary file :file:`ble5-ctr-rpmsg_<XYZ>.hex`, where *<XYZ>* corresponds to the controller version, for example :file:`ble5-ctr-rpmsg_3216.hex`.
This file includes the LE Audio Controller Subsystem for nRF53.
If :ref:`DFU is enabled <nrf53_audio_app_configuration_configure_fota>`, the subsystem's binary file will be generated in the :file:`build/zephyr/` directory and will be called :file:`net_core_app_signed.hex`.

There are two other files in the :file:`/bin` directory:

* :file:`ble5-ctr-rpmsg_shifted_<XYZ>.hex` which has been shifted to make space for MCUboot.
* :file:`ble5-ctr-rpmsg_shifted_min_<XYZ>.hex` which is the same as above, but made for minimum MCUboot.

Also for these files, *<XYZ>* corresponds to the controller version.

Limitations
***********

The controller is marked as :ref:`experimental <software_maturity>`.

This controller and the LE Audio Controller Subsystem for nRF5340 it includes has been tested and works in configurations used by the :ref:`nrf53_audio_app` application (for example, 2 concurrent CIS, or BIS).
No other configurations than the ones used in the referenced application have been tested or documented for this library.

Dependencies
************

As the controller is provided precompiled in a binary format, there are no software dependencies.
In terms of hardware, this controller is only compatible with the nRF5340.

.. toctree::
    :maxdepth: 1
    :caption: Subpages:

    API_documentation
    CHANGELOG