5.2.3

LL application

This section describes the steps needed to create a custom LL application using STM32CubeU5.

1. Create a project

To create a new project, either start from the Templates_LL project provided for each board in \Projects\<S

TM32xxx_yyy>\Templates_LL or from any available project under \Projects\<STM32xxy_yyy>\Exam

ples_LL (<STM32xxx_yyy> refers to the board name, such as NUCLEO-U575ZI-Q).

The template project provides an empty main loop function, which is a good starting point to understand the

STM32CubeU5 project settings. The template has the following characteristics:

–

It contains the source codes of the LL and CMSIS drivers, which are the minimum set of components

needed to develop code on a given board.

–

It contains the include paths for all the required firmware components.

–

It selects the supported STM32U5 device and allows the correct configuration of the CMSIS and LL

drivers.

–

It provides ready-to-use user files, which are preconfigured as follows:

◦

main.h: LED & USER_BUTTON definition abstraction layer.

◦

main.c: system clock configuration for maximum frequency.

2. Port an existing project to another board

a. Start from the Templates_LL project provided for each board, available in \Projects\<STM32xxx_yyy>

\Templates_LL.

b. Select an LL example.

Note:

To find the board on which LL examples are deployed, refer to the list of LL examples STM32CubeProje

ctsList.html.

3. Port the LL example

–

Copy/paste the Templates_LL folder to keep the initial source, or directly update an existing Templat

es_LL project.

–

Replace Templates_LL files with the Examples_LL targeted project.

–

Keep all board-specific parts. For clarity reasons, board-specific parts have been flagged with the

following specific tags:

/* ============== BOARD SPECIFIC CONFIGURATION CODE BEGIN ============== */

/* ============== BOARD SPECIFIC CONFIGURATION CODE END ============== */

The main porting steps are the following:

a. Replace the stm32u5xx_it.h file.

b. Replace the stm32u5xx_it.c file.

c. Replace the main.h file and update it. Keep the LED and user button definition from the LL template

under the "BOARD SPECIFIC CONFIGURATION" tags.

d. Replace the main.c file and update it:

•

Keep the clock configuration of the SystemClock_Config() LL template function under the

"BOARD SPECIFIC CONFIGURATION" tags.

•

Depending on LED definition, replace each LEDx occurrence with another LEDy available in

the main.h file.

With these modifications, the example now runs on the targeted board.

5.3

Getting STM32CubeU5 release updates

The new STM32CubeU5 MCU package releases and patches are available from www.st.com/stm32u5. They may

be retrieved from the [CHECK FOR UPDATE] button in STM32CubeMX. For more details, refer to section 3 of

STM32CubeMX for STM32 configuration and initialization C code generation (UM1718).

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Getting started with STM32CubeU5

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