ST STM32F2 User Manual

UM1940
Overview of HAL drivers
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2.12.2.3 HAL MSP initialization process
The peripheral initialization is done through HAL_PPP_Init() while the hardware resources
initialization used by a peripheral (PPP) is performed during this initialization by calling
MSP callback function HAL_PPP_MspInit().
The MspInit callback performs the low level initialization related to the different additional
hardware resources: RCC, GPIO, NVIC and DMA.
All the HAL drivers with handles include two MSP callbacks for initialization and de-
initialization:
/**
* @brief Initializes the PPP MSP.
* @param hppp: PPP handle
* @retval None */
void __weak HAL_PPP_MspInit(PPP_HandleTypeDef *hppp) {
/* NOTE : This function Should not be modified, when the callback is needed,
the HAL_PPP_MspInit could be implemented in the user file */
}
/**
* @brief DeInitializes PPP MSP.
* @param hppp: PPP handle
* @retval None */
void __weak HAL_PPP_MspDeInit(PPP_HandleTypeDef *hppp) {
/* NOTE : This function Should not be modified, when the callback is needed,
the HAL_PPP_MspDeInit could be implemented in the user file */
}
The MSP callbacks are declared empty as weak functions in each peripheral driver. The
user can use them to set the low level initialization code or omit them and use his own
initialization routine.
The HAL MSP callback is implemented inside the stm32f2xx_hal_msp.c file in the user
folders. An stm32f2xx_hal_msp.c file template is located in the HAL folder and should be
copied to the user folder. It can be generated automatically by STM32CubeMX tool and
further modified. Note that all the routines are declared as weak functions and could be
overwritten or removed to use user low level initialization code.
stm32f2xx_hal_msp.c file contains the following functions:
Table 14: MSP functions
Routine
Description
void HAL_MspInit()
Global MSP initialization routine
void HAL_MspDeInit()
Global MSP de-initialization routine
void HAL_PPP_MspInit()
PPP MSP initialization routine
void HAL_PPP_MspDeInit()
PPP MSP de-initialization routine
By default, if no peripheral needs to be de-initialized during the program execution, the
whole MSP initialization is done in Hal_MspInit() and MSP De-Initialization in the
Hal_MspDeInit(). In this case the HAL_PPP_MspInit() and HAL_PPP_MspDeInit() are not
implemented.
When one or more peripherals needs to be de-initialized in run time and the low level
resources of a given peripheral need to be released and used by another peripheral,
HAL_PPP_MspDeInit() and HAL_PPP_MspInit() are implemented for the concerned
peripheral and other peripherals initialization and de-Initialization are kept in the global
HAL_MspInit() and the HAL_MspDeInit().
If there is nothing to be initialized by the global HAL_MspInit() and HAL_MspDeInit(), the
two routines can simply be omitted.

ST STM32F2 Specifications

General

Brand	ST
Model	STM32F2
Category	Microcontrollers
Language	English