blob: 5861440e226bf9b6ffaa9e7572c37bf84aee3f56 [file] [log] [blame]
.. _bluetooth-ctlr-arch:
LE Controller
#############
Overview
********
.. image:: img/ctlr_overview.png
#. HCI
* Host Controller Interface, Bluetooth standard
* Provides Zephyr Bluetooth HCI Driver
#. HAL
* Hardware Abstraction Layer
* Vendor Specific, and Zephyr Driver usage
#. Ticker
* Soft real time radio/resource scheduling
#. LL_SW
* Software-based Link Layer implementation
* States and roles, control procedures, packet controller
#. Util
* Bare metal memory pool management
* Queues of variable count, lockless usage
* FIFO of fixed count, lockless usage
* Mayfly concept based deferred ISR executions
Architecture
************
Execution Overview
==================
.. image:: img/ctlr_exec_overview.png
Architecture Overview
=====================
.. image:: img/ctlr_arch_overview.png
Scheduling
**********
.. image:: img/ctlr_sched.png
Ticker
======
.. image:: img/ctlr_sched_ticker.png
Upper Link Layer and Lower Link Layer
=====================================
.. image:: img/ctlr_sched_ull_lll.png
Scheduling Variants
===================
.. image:: img/ctlr_sched_variant.png
ULL and LLL Timing
==================
.. image:: img/ctlr_sched_ull_lll_timing.png
Event Handling
**************
.. image:: img/ctlr_sched_event_handling.png
Scheduling Closely Spaced Events
================================
.. image:: img/ctlr_sched_msc_close_events.png
Aborting Active Event
=====================
.. image:: img/ctlr_sched_msc_event_abort.png
Cancelling Pending Event
========================
.. image:: img/ctlr_sched_msc_event_cancel.png
Pre-emption of Active Event
===========================
.. image:: img/ctlr_sched_msc_event_preempt.png
Data Flow
*********
Transmit Data Flow
==================
.. image:: img/ctlr_dataflow_tx.png
Receive Data Flow
=================
.. image:: img/ctlr_dataflow_rx.png
Execution Priorities
********************
.. image:: img/ctlr_exec_prio.png
- Event handle (0, 1) < Event preparation (2, 3) < Event/Rx done (4) < Tx
request (5) < Role management (6) < Host (7).
- LLL is vendor ISR, ULL is Mayfly ISR concept, Host is kernel thread.
Lower Link Layer
****************
LLL Execution
=============
.. image:: img/ctlr_exec_lll.png
LLL Resume
----------
.. image:: img/ctlr_exec_lll_resume_top.png
.. image:: img/ctlr_exec_lll_resume_bottom.png
Bare metal utilities
********************
Memory FIFO and Memory Queue
============================
.. image:: img/ctlr_mfifo_memq.png
Mayfly
======
.. image:: img/ctlr_mayfly.png
* Mayfly are multi-instance scalable ISR execution contexts
* What a Work is to a Thread, Mayfly is to an ISR
* List of functions executing in ISRs
* Execution priorities map to IRQ priorities
* Facilitate cross execution context scheduling
* Race-to-idle execution
* Lock-less, bare metal
Legacy Controller
*****************
.. image:: img/ctlr_legacy.png
Bluetooth Low Energy Controller - Vendor Specific Details
*********************************************************
Hardware Requirements
=====================
Nordic Semiconductor
--------------------
The Nordic Semiconductor Bluetooth Low Energy Controller implementation
requires the following hardware peripherals.
.. list-table:: SoC Peripheral Use
:header-rows: 1
:widths: 15 15 15 10 50
* - Resource
- nRF Peripheral
- # instances
- Zephyr Driver Accessible
- Description
* - Clock
- NRF_CLOCK
- 1
- Yes
- * A Low Frequency Clock (LFCLOCK) or sleep clock, for low power
consumption between Bluetooth radio events
* A High Frequency Clock (HFCLOCK) or active clock, for high precision
packet timing and software based transceiver state switching with
inter-frame space (tIFS) timing inside Bluetooth radio events
* - RTC [a]_
- NRF_RTC0
- 1
- **No**
- * Uses 2 capture/compare registers
* - Timer
- NRF_TIMER0 or NRF_TIMER4 [1]_, and NRF_TIMER1 [0]_
- 2 or 1 [1]_
- **No**
- * 2 instances, one each for packet timing and tIFS software switching,
respectively
* 7 capture/compare registers (3 mandatory, 1 optional for ISR profiling,
4 for single timer tIFS switching) on first instance
* 4 capture/compare registers for second instance, if single tIFS timer
is not used.
* - PPI [b]_
- NRF_PPI
- 21 channels (20 [2]_), and 2 channel groups [3]_
- Yes [4]_
- * Used for radio mode switching to achieve tIFS timings, for PA/LNA
control
* - DPPI [c]_
- NRF_DPPI
- 20 channels, and 2 channel groups [3]_
- Yes [4]_
- * Used for radio mode switching to achieve tIFS timings, for PA/LNA
control
* - SWI [d]_
- NRF_SWI4 and NRF_SWI5, or NRF_SWI2 and NRF_SWI3 [5]_
- 2
- **No**
- * 2 instances, for Lower Link Layer and Upper Link Layer Low priority
execution context
* - Radio
- NRF_RADIO
- 1
- **No**
- * 2.4 GHz radio transceiver with multiple radio standards such as 1 Mbps,
2 Mbps and Coded PHY S2/S8 Long Range Bluetooth Low Energy technology
* - RNG [e]_
- NRF_RNG
- 1
- Yes
-
* - ECB [f]_
- NRF_ECB
- 1
- **No**
-
* - CBC-CCM [g]_
- NRF_CCM
- 1
- **No**
-
* - AAR [h]_
- NRF_AAR
- 1
- **No**
-
* - GPIO [i]_
- NRF_GPIO
- 2 GPIO pins for PA and LNA, 1 each
- Yes
- * Additionally, 10 Debug GPIO pins (optional)
* - GPIOTE [j]_
- NRF_GPIOTE
- 1
- Yes
- * Used for PA/LNA
* - TEMP [k]_
- NRF_TEMP
- 1
- Yes
- * For RC sourced LFCLOCK calibration
* - UART [l]_
- NRF_UART0
- 1
- Yes
- * For HCI interface in Controller only builds
* - IPC [m]_
- NRF_IPC [5]_
- 1
- Yes
- * For HCI interface in Controller only builds
.. [a] Real Time Counter (RTC)
.. [b] Programmable Peripheral Interconnect (PPI)
.. [c] Distributed Programmable Peripheral Interconnect (DPPI)
.. [d] Software Interrupt (SWI)
.. [e] Random Number Generator (RNG)
.. [f] AES Electronic Codebook Mode Encryption (ECB)
.. [g] Cipher Block Chaining (CBC) - Message Authentication Code with Counter
Mode encryption (CCM)
.. [h] Accelerated Address Resolver (AAR)
.. [i] General Purpose Input Output (GPIO)
.. [j] GPIO tasks and events (GPIOTE)
.. [k] Temperature sensor (TEMP)
.. [l] Universal Asynchronous Receiver Transmitter (UART)
.. [m] Interprocess Communication peripheral (IPC)
.. [0] :kconfig:option:`CONFIG_BT_CTLR_TIFS_HW` ``=n``
.. [1] :kconfig:option:`CONFIG_BT_CTLR_SW_SWITCH_SINGLE_TIMER` ``=y``
.. [2] When not using pre-defined PPI channels
.. [3] For software-based tIFS switching
.. [4] Drivers that use nRFx interfaces
.. [5] For nRF53x Series