LTDC HAL module driver. This file provides firmware functions to manage the following functionalities of the LTDC peripheral: More...
#include "stm32h7xx_hal.h"
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Detailed Description
LTDC HAL module driver. This file provides firmware functions to manage the following functionalities of the LTDC peripheral:
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##### How to use this driver #####
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The LTDC HAL driver can be used as follows:
(#) Declare a LTDC_HandleTypeDef handle structure, for example: LTDC_HandleTypeDef hltdc;
(#) Initialize the LTDC low level resources by implementing the HAL_LTDC_MspInit() API:
(##) Enable the LTDC interface clock
(##) NVIC configuration if you need to use interrupt process
(+++) Configure the LTDC interrupt priority
(+++) Enable the NVIC LTDC IRQ Channel
(#) Initialize the required configuration through the following parameters:
the LTDC timing, the horizontal and vertical polarity, the pixel clock polarity,
Data Enable polarity and the LTDC background color value using HAL_LTDC_Init() function
*** Configuration ***
=========================
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(#) Program the required configuration through the following parameters:
the pixel format, the blending factors, input alpha value, the window size
and the image size using HAL_LTDC_ConfigLayer() function for foreground
or/and background layer.
(#) Optionally, configure and enable the CLUT using HAL_LTDC_ConfigCLUT() and
HAL_LTDC_EnableCLUT functions.
(#) Optionally, enable the Dither using HAL_LTDC_EnableDither().
(#) Optionally, configure and enable the Color keying using HAL_LTDC_ConfigColorKeying()
and HAL_LTDC_EnableColorKeying functions.
(#) Optionally, configure LineInterrupt using HAL_LTDC_ProgramLineEvent()
function
(#) If needed, reconfigure and change the pixel format value, the alpha value
value, the window size, the window position and the layer start address
for foreground or/and background layer using respectively the following
functions: HAL_LTDC_SetPixelFormat(), HAL_LTDC_SetAlpha(), HAL_LTDC_SetWindowSize(),
HAL_LTDC_SetWindowPosition() and HAL_LTDC_SetAddress().
(#) Variant functions with _NoReload suffix allows to set the LTDC configuration/settings without immediate reload.
This is useful in case when the program requires to modify serval LTDC settings (on one or both layers)
then applying(reload) these settings in one shot by calling the function HAL_LTDC_Reload().
After calling the _NoReload functions to set different color/format/layer settings,
the program shall call the function HAL_LTDC_Reload() to apply(reload) these settings.
Function HAL_LTDC_Reload() can be called with the parameter ReloadType set to LTDC_RELOAD_IMMEDIATE if
an immediate reload is required.
Function HAL_LTDC_Reload() can be called with the parameter ReloadType set to LTDC_RELOAD_VERTICAL_BLANKING if
the reload should be done in the next vertical blanking period,
this option allows to avoid display flicker by applying the new settings during the vertical blanking period.
(#) To control LTDC state you can use the following function: HAL_LTDC_GetState()
*** LTDC HAL driver macros list ***
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Below the list of most used macros in LTDC HAL driver.
(+) __HAL_LTDC_ENABLE: Enable the LTDC.
(+) __HAL_LTDC_DISABLE: Disable the LTDC.
(+) __HAL_LTDC_LAYER_ENABLE: Enable an LTDC Layer.
(+) __HAL_LTDC_LAYER_DISABLE: Disable an LTDC Layer.
(+) __HAL_LTDC_RELOAD_IMMEDIATE_CONFIG: Reload Layer Configuration.
(+) __HAL_LTDC_GET_FLAG: Get the LTDC pending flags.
(+) __HAL_LTDC_CLEAR_FLAG: Clear the LTDC pending flags.
(+) __HAL_LTDC_ENABLE_IT: Enable the specified LTDC interrupts.
(+) __HAL_LTDC_DISABLE_IT: Disable the specified LTDC interrupts.
(+) __HAL_LTDC_GET_IT_SOURCE: Check whether the specified LTDC interrupt has occurred or not.
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(@) You can refer to the LTDC HAL driver header file for more useful macros
*** Callback registration ***
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The compilation define USE_HAL_LTDC_REGISTER_CALLBACKS when set to 1
allows the user to configure dynamically the driver callbacks.
Use function HAL_LTDC_RegisterCallback() to register a callback.
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Function HAL_LTDC_RegisterCallback() allows to register following callbacks:
(+) LineEventCallback : LTDC Line Event Callback.
(+) ReloadEventCallback : LTDC Reload Event Callback.
(+) ErrorCallback : LTDC Error Callback
(+) MspInitCallback : LTDC MspInit.
(+) MspDeInitCallback : LTDC MspDeInit.
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This function takes as parameters the HAL peripheral handle, the callback ID
and a pointer to the user callback function.
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Use function HAL_LTDC_UnRegisterCallback() to reset a callback to the default
weak function.
HAL_LTDC_UnRegisterCallback() takes as parameters the HAL peripheral handle
and the callback ID.
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This function allows to reset following callbacks:
(+) LineEventCallback : LTDC Line Event Callback
(+) ReloadEventCallback : LTDC Reload Event Callback
(+) ErrorCallback : LTDC Error Callback
(+) MspInitCallback : LTDC MspInit
(+) MspDeInitCallback : LTDC MspDeInit.
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By default, after the HAL_LTDC_Init and when the state is HAL_LTDC_STATE_RESET
all callbacks are set to the corresponding weak functions:
examples HAL_LTDC_LineEventCallback(), HAL_LTDC_ErrorCallback().
Exception done for MspInit and MspDeInit functions that are
reset to the legacy weak (surcharged) functions in the HAL_LTDC_Init() and HAL_LTDC_DeInit()
only when these callbacks are null (not registered beforehand).
If not, MspInit or MspDeInit are not null, the HAL_LTDC_Init() and HAL_LTDC_DeInit()
keep and use the user MspInit/MspDeInit callbacks (registered beforehand).
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Callbacks can be registered/unregistered in HAL_LTDC_STATE_READY state only.
Exception done MspInit/MspDeInit that can be registered/unregistered
in HAL_LTDC_STATE_READY or HAL_LTDC_STATE_RESET state,
thus registered (user) MspInit/DeInit callbacks can be used during the Init/DeInit.
In that case first register the MspInit/MspDeInit user callbacks
using HAL_LTDC_RegisterCallback() before calling HAL_LTDC_DeInit()
or HAL_LTDC_Init() function.
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When the compilation define USE_HAL_LTDC_REGISTER_CALLBACKS is set to 0 or
not defined, the callback registration feature is not available and all callbacks
are set to the corresponding weak functions.- Attention
© Copyright (c) 2017 STMicroelectronics. All rights reserved.
This software component is licensed by ST under BSD 3-Clause license, the "License"; You may not use this file except in compliance with the License. You may obtain a copy of the License at: opensource.org/licenses/BSD-3-Clause
Definition in file stm32h7xx_hal_ltdc.c.