Getting started with STM32CubeL4 for STM32L4 Series

Getting started with STM32CubeL4 for STM32L4 Series
UM1860
User manual
Getting started with STM32CubeL4 for STM32L4 Series
Introduction
STMCube™ is an STMicroelectronics original initiative to ease developers’ life by reducing
development efforts, time and cost. STM32Cube is the implementation of STMCube™ that
covers STM32 microcontrollers.
STM32Cube Version 1.x includes:
•
The STM32CubeMX, a graphical software configuration tool that allows the generation
of C initialization code using graphical wizards.
•
A comprehensive embedded software platform, delivered per series (such as
STM32CubeL4 for STM32L4 series):
–
The STM32Cube HAL, an STM32 abstraction layer embedded software ensuring
maximized portability across STM32 portfolio. The HAL is available for all
peripherals
–
The Low Layer APIs (LL) offering a fast light-weight expert-oriented layer which is
closer to the hardware than the HAL. The LL APIs are available only for a set of
peripherals.
–
A consistent set of middleware components such as RTOS, USB, STMTouch™,
FatFS and Graphics
–
All embedded software utilities coming with a full set of examples.
This user manual describes how to get started with the STM32CubeL4 firmware package.
Section 1 describes the main features of STM32CubeL4 firmware, part of the STMCube™
initiative. Section 2 and Section 3 provide an overview of the STM32CubeL4 architecture
and firmware package structure.
September 2015
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1
Contents
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Contents
1
STM32CubeL4 main features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2
STM32CubeL4 architecture overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.1
2.2
2.3
3
4
Level 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.1.1
Board Support Package (BSP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.1.2
Hardware Abstraction Layer (HAL) and Low Layer (LL) . . . . . . . . . . . . . 9
2.1.3
Basic peripheral usage examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Level 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.2.1
Middleware components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.2.2
Examples based on the middleware components . . . . . . . . . . . . . . . . . 11
Level 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
STM32CubeL4 firmware package overview . . . . . . . . . . . . . . . . . . . . . 13
3.1
Supported STM32L4 devices and hardware . . . . . . . . . . . . . . . . . . . . . . 13
3.2
Firmware package overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Getting started with STM32CubeL4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.1
Running your first example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.2
Developing your own application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.3
Using STM32CubeMX to generate initialization C code . . . . . . . . . . . . . 20
4.4
Getting STM32CubeL4 release updates . . . . . . . . . . . . . . . . . . . . . . . . . 21
4.4.1
5
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Installing and running the STM32CubeUpdater program . . . . . . . . . . . 21
FAQ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
5.1
What is the license scheme for the STM32CubeL4 firmware? . . . . . . . . 22
5.2
What boards are supported by the STM32CubeL4 firmware package? . 22
5.3
Are any examples provided with the ready-to-use toolset projects? . . . . 22
5.4
Is there any link with Standard Peripheral Libraries? . . . . . . . . . . . . . . . . 22
5.5
Does the HAL drivers take benefit from interrupts or DMA?
How can this be controlled? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
5.6
How are the product/peripheral specific features managed? . . . . . . . . . . 22
5.7
How can STM32CubeMX generate code based on embedded software? 23
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Contents
5.8
How can I get regular updates on the latest STM32CubeL4
firmware releases? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
5.9
When should I use HAL versus LL drivers? . . . . . . . . . . . . . . . . . . . . . . . 23
5.10
How can I include LL drivers in my environment?
Is there any LL configuration file as for HAL? . . . . . . . . . . . . . . . . . . . . . 23
5.11
Can I use HAL and LL drivers together? If yes, what are the constraints? 23
5.12
Is there any LL APIs which are not available with HAL . . . . . . . . . . . . . . 24
5.13
Why are SysTick interrupts not enabled on LL drivers? . . . . . . . . . . . . . . 24
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
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3
List of tables
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List of tables
Table 1.
Table 2.
Table 3.
Table 4.
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Macros for STM32L4 series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Boards for STM32L4 series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Number of examples available for each board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
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List of figures
List of figures
Figure 1.
Figure 2.
Figure 3.
Figure 4.
STM32CubeL4 firmware components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
STM32CubeL4 firmware architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
STM32CubeL4 firmware package structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
STM32CubeL4 examples overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
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5
STM32CubeL4 main features
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STM32CubeL4 main features
STM32CubeL4 gathers, in a single package, all the generic embedded software
components required to develop an application on STM32L4 microcontrollers. In line with
the STMCube™ initiative, this set of components is highly portable, not only within
STM32L4 series but also to other STM32 series.
STM32CubeL4 is fully compatible with STM32CubeMX code generator that allows
generating initialization code. The package includes Low Layer (LL) and hardware
abstraction layer (HAL) APIs that cover the microcontroller hardware, together with an
extensive set of examples running on STMicroelectronics boards. The HAL and LL APIs are
available in open-source BSD license for user convenience.
STM32CubeL4 package also contains a set of middleware components with the
corresponding examples. They come in free user-friendly license terms:
•
Full USB Host and Device stack supporting many classes.
–
Host Classes: HID, MSC, CDC, Audio, MTP
–
Device Classes: HID, MSC, CDC, Audio, DFU, LPM, BCD.
•
STemWin, a professional graphical stack solution available in binary format and based
on STMicroelectronics partner solution SEGGER emWin
•
CMSIS-RTOS implementation with FreeRTOS open source solution
•
FAT File system based on open source FatFS solution
•
STMTouch touch sensing library solution.
Several applications and demonstrations implementing all these middleware components
are also provided in the STM32CubeL4 package.
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STM32CubeL4 main features
Figure 1. STM32CubeL4 firmware components
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STM32CubeL4 architecture overview
2
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STM32CubeL4 architecture overview
The STM32Cube firmware solution is built around three independent levels that can easily
interact with each other’s as described in Figure 2:
Figure 2. STM32CubeL4 firmware architecture
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2.1
Level 0
This level is divided into three sub-layers:
•
•
•
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Board Support Package (BSP)
Hardware Abstraction Layer (HAL)
–
HAL peripheral drivers
–
Low Layer drivers
Basic peripheral usage examples.
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2.1.1
STM32CubeL4 architecture overview
Board Support Package (BSP)
This layer offers a set of APIs relative to the hardware components in the hardware boards
(such as LCD, Audio, microSD, MEMS drivers). It is composed of two parts:
•
Component
This is the driver relative to the external device on the board and not to the STM32. The
component driver provide specific APIs to the BSP driver external components and
could be portable on any other board.
•
BSP driver
It allows linking the component driver to a specific board and provides a set of userfriendly APIs. The API naming rule is BSP_FUNCT_Action().
Example: BSP_LED_Init(), BSP_LED_On()
The BSP is based on a modular architecture allowing an easy porting on any hardware by
just implementing the low-level routines.
2.1.2
Hardware Abstraction Layer (HAL) and Low Layer (LL)
The STM32CubeL4 HAL and LL are complementary and cover a wide range of applications
requirements:
•
The HAL drivers offer high-level function-oriented highly-portable APIs. They hide the
MCU and peripheral complexity to end user.
The HAL drivers provide generic multi-instance feature-oriented APIs which simplify
user application implementation by providing ready to use process. As example, for the
communication peripherals (I2S, UART…), it provides APIs allowing initializing and
configuring the peripheral, managing data transfer based on polling, interrupt or DMA
process, and handling communication errors that may raise during communication.
The HAL driver APIs are split in two categories:
•
–
Generic APIs which provides common and generic functions to all the STM32
series
–
Extension APIs which provides specific and customized functions for a specific
family or a specific part number.
The Low Layer APIs provide low-level APIs at register level, with better optimization but
less portability. They require a deep knowledge of MCU and peripheral specifications.
The LL drivers are designed to offer a fast light-weight expert-oriented layer which is
closer to the hardware than the HAL. Contrary to the HAL, LL APIs are not provided for
peripherals where optimized access is not a key feature, or for those requiring heavy
software configuration and/or complex upper-level stack (such as FSMC, USB, or
SDMMC).
They feature:
2.1.3
–
A set of inline functions for direct and atomic register access
–
Full independence from HAL and capability to be used in standalone mode
(without HAL drivers)
–
Full coverage of the supported peripheral features.
Basic peripheral usage examples
This layer includes the examples build over the STM32 peripheral and using either the HAL
or/and the Low Layer drivers APIs as well as the BSP resources.
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STM32CubeL4 architecture overview
2.2
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Level 1
This level is divided into two sub-layers:
•
•
2.2.1
Middleware components
Examples based on the middleware components.
Middleware components
The middleware is a set of libraries covering USB Host and Device Libraries, STMTouch
touch sensing, STemWin, FreeRTOS and FatFS. Horizontal interactions between the
components of this layer is done directly by calling the feature APIs while the vertical
interaction with the low-level drivers is done through specific callbacks and static macros
implemented in the library system call interface. For example, the FatFs implements the disk
I/O driver to access microSD drive or the USB Mass Storage Class.
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STM32CubeL4 architecture overview
The main features of each middleware component are as follows:
•
•
•
•
•
USB Host and Device Libraries
–
Several USB classes supported (Mass-Storage, HID, CDC, DFU, LPM and BCD).
–
Support of multi-packet transfer features that allows sending big amounts of data
without splitting them into maximum packet size transfers.
–
Use of configuration files to change the core and the library configuration without
changing the library code (Read Only).
–
32-bit aligned data structures to handle DMA-based transfer in high-speed modes.
–
Support of multi USB OTG core instances from user level through configuration
file. This allows to perform operations with more than one USB host/device
peripheral.
–
RTOS and Standalone operation.
–
Link with low-level driver through an abstraction layer using the configuration file
to avoid any dependency between the Library and the low-level drivers.
STemWin Graphical stack
–
Professional grade solution for GUI development based on SEGGER’s emWin
solution.
–
Optimized display drivers.
–
Software tools for code generation and bitmap editing (STemWin Builder…).
FreeRTOS
–
Open source standard.
–
CMSIS compatibility layer.
–
Tickless operation during low-power mode.
–
Integration with all STM32Cube middleware modules.
FAT File system
–
FATFS FAT open source library.
–
Long file name support.
–
Dynamic multi-drive support.
–
RTOS and standalone operation.
–
Examples with microSD.
STM32 Touch sensing library
Robust STMTouch capacitive touch sensing solution supporting proximity, touchkey,
linear and rotary touch sensors. It is based a proven surface charge transfer acquisition
principle.
2.2.2
Examples based on the middleware components
Each middleware component comes with one or more examples (called also Applications)
showing how to use it. Integration examples that use several middleware components are
provided as well.
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2.3
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Level 2
This level is composed of a single layer which consist in a global real-time and graphical
demonstration based on the middleware service layer, the low-level abstraction layer and
the basic peripheral usage applications for board based features.
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STM32CubeL4 firmware package overview
3
STM32CubeL4 firmware package overview
3.1
Supported STM32L4 devices and hardware
STM32Cube offers highly portable Hardware Abstraction Layer (HAL) built around a generic
architecture. It allows the build-upon layers, such as the middleware layer, to implement
their functions without knowing, in-depth, the MCU used. This improves the library code reusability and guarantees an easy portability on other devices.
In addition, thanks to its layered architecture, the STM32CubeL4 offers full support of all
STM32L4 series. The user has only to define the right macro in stm32l4xx.h.
Table 1 gives the macro to be defined depending on the STM32L4 device used. This macro
must also be defined in the compiler preprocessor.
Table 1. Macros for STM32L4 series
Macro defined in
stm32l4xx.h
STM32L4 devices
STM32L471xx
STM32L471RG, STM32L471JG, STM32L471VG, STM32L471QG,
STM32L471ZG, STM32L471RE, STM32L471JE, STM32L471VE,
STM32L471QE, STM32L471ZE
STM32L475xx
STM32L475RG, STM32L475JG, STM32L475VG, STM32L475QG,
STM32L475ZG, STM32L475RE, STM32L475JE, STM32L475VE,
STM32L475QE, STM32L475ZE, STM32L475RC, STM32L475VC
STM32L476xx
STM32L476RG, STM32L476JG, STM32L476VG, STM32L476QG,
STM32L476ZG, STM32L476RE, STM32L476JE, STM32L476VE,
STM32L476QE, STM32L476ZE, STM32L476RC, STM32L476VC
STM32L485xx
STM32L485JC, STM32L485JE
STM32L486xx
STM32L486RG, STM32L486JG, STM32L486VG, STM32L486QG,
STM32L486ZG
STM32CubeL4 features a rich set of examples and applications at all levels making it easy
to understand and use any HAL driver and/or middleware components. These examples are
running on STMicroelectronics boards as listed in Table 2.
Table 2. Boards for STM32L4 series
Board
STM32L4 devices supported
STM32L476G-EVAL
STM32L476xx
32L476GDISCOVERY
STM32L476xx
NUCLEO-L476RG
STM32L476xx
As for all other STM32 Nucleo boards, the NUCLEO-L476RG feature a reduced set of
hardware components (one user key button and one user LED). To enrich the middleware
support offer for the STM32CubeL4 firmware package, an LCD display Adafruit Arduino™
shield is used. This shield embeds a microSD connector and a joystick in addition to the
LCD.
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STM32CubeL4 firmware package overview
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In the BSP component, the dedicated drivers for the Arduino shield are available. Their use
is illustrated through either the provided BSP example or in the demonstration firmware,
without forgetting the FatFS middleware application.
The STM32CubeL4 firmware is able to run on any compatible hardware. The user simply
updates the BSP drivers to port the provided examples on his own board, if this later has the
same hardware features (LED, LCD display, buttons...).
3.2
Firmware package overview
The STM32CubeL4 firmware solution is provided in one single zip package having the
structure shown in Figure 3.
Figure 3. STM32CubeL4 firmware package structure
1. The library files in brown must not be modified by the user, while the files in blue can be modified.
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STM32CubeL4 firmware package overview
For each board, a set of examples are provided with pre-configured projects for EWARM,
MDK-ARM, SW4STM32 and TrueSTUDIO toolchains.
Figure 4 shows the projects structure for the NUCLEO-L476RG board.
Figure 4. STM32CubeL4 examples overview
The examples are classified depending on the STM32Cube level they apply to, and are
named as explained below:
•
Level 0 examples are called Examples, Examples_LL and Examples_MIX. They use
respectively HAL drivers, LL drivers and a mix of HAL and LL drivers without any
middleware component.
•
Level 1 examples are called Applications. They provide typical use cases of each
middleware component.
The Template project available in the Template directory allows to quickly build a firmware
application on a given board.
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All examples have the same structure:
•
\Inc folder that contains all header files.
•
\Src folder for the sources code.
•
\EWARM, \MDK-ARM, /SW4STM32 and \TrueSTUDIO folders contain the preconfigured project for each toolchain.
•
readme.txt describing the example behavior and needed environment to make it
working
Table 3 gives the number of projects available for each board.
Table 3. Number of examples available for each board
Board
HAL examples
LL examples
Mixed HAL/LL
examples
Applications
Demonstration
STM32L476G-EVAL
84
0
0
28
1
32L476GDISCOVERY
16
0
0
1
1
NUCLEO-L476RG
64
72
12
1
1
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Getting started with STM32CubeL4
4
Getting started with STM32CubeL4
4.1
Running your first example
This section explains how simple is to run a first example within STM32CubeL4. It uses as
illustration the generation of a simple LED toggle running on STM32L476RG Nucleo board:
1.
Download the STM32CubeL4 firmware package. Unzip it into a directory of your
choice. Make sure not to modify the package structure shown in Figure 3. Note that it is
also recommended to copy the package at a location close to your root volume (e.g.
C\Eval or G:\Tests) because some IDEs encounter problems when the path length is
too long.
2.
Browse to \Projects\STM32L476RG-Nucleo\Examples.
3.
Open \GPIO, then \GPIO_EXTI folder.
4.
Open the project with your preferred toolchain. A quick overview on how to open, build
and run an example with the supported toolchains is given below.
5.
Rebuild all files and load your image into target memory.
6.
Run the example: each time you press the USER pushbutton, the LED2 toggles (for
more details, refer to the example readme file).
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To open, build and run an example with the supported toolchains:, follow the steps below:
•
•
•
•
4.2
EWARM
a)
Under the example folder, open \EWARM sub-folder.
b)
Launch the Project.eww workspace(a).
c)
Rebuild all files: Project->Rebuild all.
d)
Load project image: Project->Debug.
e)
Run program: Debug->Go(F5).
MDK-ARM
a)
Under the example folder, open \MDK-ARM sub-folder.
b)
Launch the Project.uvprojx workspace(a).
c)
Rebuild all files: Project->Rebuild all target files.
d)
Load project image: Debug->Start/Stop Debug Session.
e)
Run program: Debug->Run (F5).
SW4STM32
a)
Open the SW4STM32 toolchain
b)
Click File->Switch Workspace->Other and browse to the SW4STM32
workspace directory
c)
Click File->Import, select General->Existing Projects into Workspace and then
click Next.
d)
Browse to the SW4STM32 workspace directory and select the project.
e)
Rebuild all project files: select the project in the Project explorer window then
click the Project->build project menu.
f)
Run program: Run->Debug (F11)
TrueSTUDO
a)
Open the TrueSTUDIO toolchain.
b)
Click File->Switch Workspace->Other and browse to TrueSTUDIO workspace
directory.
c)
Click File->Import, select General->Existing Projects into Workspace and then
click Next.
d)
Browse to the TrueSTUDIO workspace directory, select the project.
e)
Rebuild all project files: select the project in the Project explorer window then
click the Project->build project menu.
f)
Run program: Run->Debug (F11).
Developing your own application
This section describes the steps required to create your own application using
STM32CubeL4:
1.
Create your project
To create a new project, you can either start from the Template project provided for
each board under \Projects\<STM32xxx_yyy>\Templates or from any available project
a. The workspace name may change from one example to another.
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Getting started with STM32CubeL4
under \Projects\<STM32xxy_yyy>\Examples or \Projects\<STM32xx_yyy>\Applications
(where <STM32xxx_yyy> refers to the board name, e.g. STM32L476G-EVAL).
The Template project is providing empty main loop function, however it’s a good
starting point to get familiar with project settings for STM32CubeL4. The template has
the following characteristics:
–
It contains the source code of HAL, CMSIS and BSP drivers which are the minimal
components required to develop a code on a given board.
–
It contains the include paths for all the firmware components.
–
It defines the STM32L4 device supported, thus allowing to configure the CMSIS
and HAL drivers accordingly.
–
It provides read-to-use user files pre-configured as shown below:
HAL initialized with default time base with ARM Core SysTick.
SysTick ISR implemented for HAL_Delay() purpose.
Note:
When copying an existing project to another location, make sure to update the include
paths.
2.
Add the necessary middleware to your project (optional)
The available middleware stacks are: USB Host and Device library, STMTouch touch
sensing, STemWin, FreeRTOS and FatFS. To know which source files you need to add
in the project files list, refer to the documentation provided for each middleware. You
can also look at the Applications available under
\Projects\STM32xxx_yyy\Applications\<MW_Stack> (where <MW_Stack> refers to the
middleware stack, e.g. USB_Device) to know which sources files and which include
paths have to be added.
3.
Configure the firmware components
The HAL and middleware components offer a set of build time configuration options
using macros # define declared in a header file. A template configuration file is
provided within each component, it has to be copied to the project folder (usually the
configuration file is named xxx_conf_template.h, the word ‘_template’ needs to be
removed when copying it to the project folder). The configuration file provides enough
information to know the impact of each configuration option. More detailed information
is available in the documentation provided for each component.
4.
Start the HAL Library
After jumping to the main program, the application code must call HAL_Init() API to
initialize the HAL Library, which do the following tasks:
5.
a)
Configuration of the Flash prefetch and SysTick interrupt priority (through macros
defined in stm32l4xx_hal_conf.h).
b)
Configuration of the SysTick to generate an interrupt each 1 msecond at the
SysTick interrupt priority TICK_INT_PRIO defined in stm32l4xx_hal_conf.h, which
is clocked by the MSI (at this stage, the clock is not yet configured and thus the
system is running from the internal 4 MHz MSI).
c)
Setting of NVIC Group Priority to 4.
d)
Call of HAL_MspInit() callback function defined in stm32l4xx_hal_msp.c user file
to perform global low-level hardware initializations.
Configure the system clock
The system clock configuration is done by calling the two APIs described below:
a)
HAL_RCC_OscConfig(): this API configures the internal and/or external
oscillators, as well as the PLL source and factors. The user can choose to
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configure one oscillator or all oscillators. The PLL configuration can be skipped if
there is no need to run the system at high frequency.
b)
6.
7.
HAL_RCC_ClockConfig(): this API configures the system clock source, the Flash
memory latency and AHB and APB prescalers.
Initialize the peripheral
a)
First write the peripheral HAL_PPP_MspInit function. Proceed as follows:
–
Enable the peripheral clock.
–
Configure the peripheral GPIOs.
–
Configure DMA channel and enable DMA interrupt (if needed).
–
Enable peripheral interrupt (if needed).
b)
Edit the stm32xxx_it.c to call the required interrupt handlers (peripheral and DMA),
if needed.
c)
Write process complete callback functions if you plan to use peripheral interrupt or
DMA.
d)
In your main.c file, initialize the peripheral handle structure then call the function
HAL_PPP_Init() to initialize your peripheral.
Develop your application
At this stage, your system is ready and you can start developing your application code.
–
The HAL provides intuitive and ready-to-use APIs to configure the peripheral. It
supports polling, interrupts and DMA programming model, to accommodate any
application requirements. For more details on how to use each peripheral, refer to
the rich examples set provided in the STM32CubeL4 package.
–
If your application has some real-time constraints, you can found a large set of
examples showing how to use FreeRTOS and integrate it with all middleware
stacks provided within STM32CubeL4. This can be a good starting point to
develop your application.
Caution:
In the default HAL implementation, SysTick timer is used as timebase: it generates
interrupts at regular time intervals. If HAL_Delay() is called from peripheral ISR process,
make sure that the SysTick interrupt has higher priority (numerically lower) than the
peripheral interrupt. Otherwise, the caller ISR process will be blocked. Functions affecting
timebase configurations are declared as __weak to make override possible in case of other
implementations in user file (using a general purpose timer for example or other time
source). For more details, refer to HAL_TimeBase example.
4.3
Using STM32CubeMX to generate initialization C code
An alternative to steps 1 to 6 described in Section 4.2 consists in using the STM32CubeMX
tool to generate code to initialize the system, peripherals and middleware (steps 1 to 6
above) through a step-by-step process:
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1.
Select the STMicroelectronics STM32 microcontroller that matches the required set of
peripherals.
2.
Configure each required embedded software thanks to a pinout-conflict solver, a clocktree setting helper, a power consumption calculator, and the utility performing MCU
peripheral configuration (e.g. GPIO or USART) and middleware stacks (e.g. USB).
3.
Generate the initialization C code based on the configuration selected. This code is
ready-to-use within several development environments. The user code is kept at the
next code generation.
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Getting started with STM32CubeL4
For more information, please refer to STM32CubeMX user manual (UM1718).
4.4
Getting STM32CubeL4 release updates
The STM32CubeL4 firmware package comes with an updater utility, STM32CubeUpdater,
also available as a menu within STM32CubeMX code generation tool.
The updater solution detects new firmware releases and patches available from www.st.com
and proposes to download them to the user’s computer.
4.4.1
Installing and running the STM32CubeUpdater program
Follow the sequence below to install and run the STM32CubeUpdater:
1.
To launch the installation, double-click the SetupSTM32CubeUpdater.exe file.
2.
Accept the license terms and follow the different installation steps.
3.
Upon successful installation, STM32CubeUpdater becomes available as an
STMicroelectronics program under Program Files and is automatically launched. The
STM32CubeUpdater icon appears in the system tray. Right-click the updater icon and
select Updater Settings to configure the Updater connection and whether to perform
manual or automatic checks. For more details on Updater configuration, refer to
section 3 of STM32CubeMX user manual - UM1718).
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5
FAQ
5.1
What is the license scheme for the STM32CubeL4 firmware?
The HAL is distributed under a non-restrictive BSD (Berkeley Software Distribution) license.
The middleware stacks made by STMicroelectronics (USB Host and Device Libraries,
STemWin) come with a licensing model allowing easy reuse, provided it runs on an
STMicroelectronics device.
The middleware based on well-known open-source solutions (FreeRTOS and FatFs) have
user-friendly license terms. For more details, refer to the license agreement of each
middleware.
5.2
What boards are supported by the STM32CubeL4 firmware
package?
The STM32CubeL4 firmware package provides BSP drivers and ready-to-use examples for
the following STM32L4 boards: STM32L476G-EVAL, 32L476GDISCOVERY and NUCLEOL476RG.
5.3
Are any examples provided with the ready-to-use toolset
projects?
Yes. STM32CubeL4 provides a rich set of examples and applications. They come with the
pre-configured projects for IAR, Keil and GCC toolchains.
5.4
Is there any link with Standard Peripheral Libraries?
The STM32Cube HAL and LL drivers are the replacement of the standard peripheral library:
5.5
•
The HAL drivers offer a higher abstraction level compared to the standard peripheral
APIs. They focus on peripheral common features rather than hardware. Their higher
abstraction level allows defining a set of user-friendly APIs that can be easily ported
from one product to another.
•
The LL drivers offer low-level APIs at registers level.
Does the HAL drivers take benefit from interrupts or DMA?
How can this be controlled?
Yes, they do. The HAL layer supports three API programming models: polling, interrupt and
DMA (with or without interrupt generation).
5.6
How are the product/peripheral specific features managed?
The HAL drivers offer extended APIs, i.e. specific functions as add-ons to the common API
to support features available on some products/lines only.
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5.7
FAQ
How can STM32CubeMX generate code based on embedded
software?
STM32CubeMX has a built-in knowledge of STM32 microcontrollers, including their
peripherals and software, that allows to provide a graphical representation to the user and
generate *.h/*.c files based on user configuration.
5.8
How can I get regular updates on the latest STM32CubeL4
firmware releases?
The STM32CubeL4 firmware package comes with an updater utility, STM32CubeUpdater,
that can be configured for automatic or on-demand checks for new firmware package
updates (new releases or/and patches).
STM32CubeUpdater is integrated as well within the STM32CubeMX tool. When using this
tool for STM32L4 configuration and initialization C code generation, the user can benefit
from STM32CubeMX self-updates as well as STM32CubeL4 firmware package updates.
For more details, refer to Section 4.4.
5.9
When should I use HAL versus LL drivers?
HAL drivers offer high-level and function-oriented APIs, with a high level of portability.
Product/IPs complexity is hidden for end users.
LL drivers offer low-level APIs at registers level, with a better optimization but less
portability. They require a deep knowledge of product/IPs specifications.
5.10
How can I include LL drivers in my environment?
Is there any LL configuration file as for HAL?
There is no configuration file. Source code shall directly include the necessary
stm32l4xx_ll_ppp.h file(s).
5.11
Can I use HAL and LL drivers together? If yes, what are the
constraints?
It is possible to use both HAL and LL drivers. One can handle the IP initialization phase with
HAL and then manage the I/O operations with LL drivers.
The major difference between HAL and LL is that HAL drivers require to create and use
handles for operation management while LL drivers operates directly on peripheral
registers. Mixing HAL and LL is illustrated in Examples_MIX example.
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FAQ
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Is there any LL APIs which are not available with HAL
Yes, there are.
A few Cortex® APIs have been added in stm32l4xx_ll_cortex.h e.g. for accessing SCB or
SysTick registers.
5.13
Why are SysTick interrupts not enabled on LL drivers?
When using LL drivers in standalone mode, you do not need to enable SysTick interrupts
because they are not used in LL APIs, while HAL functions requires SysTick interrupts to
manage timeouts.
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Revision history
Revision history
Table 4. Document revision history
Date
Revision
16-Feb-2015
1
Initial release.
2
Added STM32L475xx and STM32L485xx in Table 1:
Macros for STM32L4 series.
Added Low Layer (LL) drivers in Section : Introduction,
Section 1: STM32CubeL4 main features, Section 2:
STM32CubeL4 architecture overview and Section 3:
STM32CubeL4 firmware package overview.
Added new Examples_LL and Examples_MIX examples
in Section 3.2: Firmware package overview/
Added SW4STM32 toolchain in Section 3.2: Firmware
package overview and in Section 4.1: Running your first
example.
Updated Section 5: FAQ to add low-layer drivers.
15-Sep-2015
Changes
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