STM32CubeF4

/**
@page LCD_DSI_ULPM_Data : LCD DSI example : enter and exit DSI ULPM Mode on data lane only,
while displaying a picture 800x480 (WVGA) in landscape mode in DSI mode Video Burst on LCD
screen.

@verbatim
******************** (C) COPYRIGHT 2017 STMicroelectronics *******************
* @file LCD_DSI/LCD_DSI_ULPM_Data/readme.txt
* @author MCD Application Team
* @brief Description of the LCD DSI enter and exit DSI ULPM Mode on data lane only example.
******************************************************************************
*
* 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
*
******************************************************************************
@endverbatim

@par Example Description

This example provides a description of how to use the embedded LCD DSI controller
(using IPs LTDC and DSI Host) to drive the KoD LCD mounted on board and manage entry and exit in
DSI ULPM mode on data lane only. In this mode, the DSI PHY state machine is entering a low power state
on data lane and allows to save some power when the LCD does not need to display.
When the display is needed again, the DSI ULPM on data lane is exited and display should operate as before.

In this example a WVGA landscape picture (800x480) is displayed on LCD in DSI Mode Video Burst.
On a USER button press from the user, the LCD display will be switched off. 100ms later,
the DSI PHY Data lane will enter ULPM mode. After 2 seconds in Off mode, the ULPM on data lane
will be exited, the LCD will be switched back on and display the same image as before with a
text notifying that the exit from ULPM was successful.

The image candies_800x480_argb8888 is of format ARGB8888 and is initially copied from Flash to SDRAM Frame Buffer.
The LTDC is reading continuously the LCD Frame buffer from SDRAM, sent it to DSI Host which sends it in burst mode (DCS commands)
via the DSI DPHY to the KoD display that decodes DSI packets and refresh its internal Graphic RAM to display on glass.
The Frame number display is managed by the BSP_LCD by function implementing font to display a text in SDRAM Frame buffer.

LED1 ON: DSI PHY Data lane in ULPM mode
LED1 OFF: DSI PHY Data lane in run mode
LED3 ON: an error occured.

@note Care must be taken when using HAL_Delay(), this function provides accurate
delay (in milliseconds) based on variable incremented in SysTick ISR. This
implies that if HAL_Delay() is called from a peripheral ISR process, then
the SysTick interrupt must have higher priority (numerically lower)
than the peripheral interrupt. Otherwise the caller ISR process will be blocked.
To change the SysTick interrupt priority you have to use HAL_NVIC_SetPriority() function.

@note The application need to ensure that the SysTick time base is always set to 1 millisecond
to have correct HAL operation.

@par Keywords

Graphic, Display, LCD, DSI, MIPI Alliance, Ultra low power mode, Tearing effect, Partial refresh, Single buffer,
LTDC, WVGA, ARGB8888, SDRAM, Burst mode

@par Directory contents

- LCD_DSI/LCD_DSI_ULPM_Data/Inc/stm32f4xx_hal_conf.h HAL configuration file
- LCD_DSI/LCD_DSI_ULPM_Data/Inc/stm32f4xx_it.h Interrupt handlers header file
- LCD_DSI/LCD_DSI_ULPM_Data/Inc/main.h Header for main.c module
- LCD_DSI/LCD_DSI_ULPM_Data/Inc/candies_800x480_argb8888.h Image 800x480 in ARGB8888 to display on LCD
- LCD_DSI/LCD_DSI_ULPM_Data/Src/stm32f4xx_it.c Interrupt handlers
- LCD_DSI/LCD_DSI_ULPM_Data/Src/main.c Main program
- LCD_DSI/LCD_DSI_ULPM_Data/Src/stm32f4xx_hal_msp.c HAL MSP file
- LCD_DSI/LCD_DSI_ULPM_Data/Src/system_stm32f4xx.c STM32F4xx system source file

@par Hardware and Software environment

- This example runs on STM32F469xx devices.

- This example has been tested with STMicroelectronics STM32469I-DISCOVERY
board and can be easily tailored to any other supported device
and development board.

- This example is configured to run by default on STM32469I-DISCO RevC board.
- In order to run this example on RevA or RevB boards, replace the flag
USE_STM32469I_DISCO_REVC, which is defined in the pre-processor options, by
either USE_STM32469I_DISCO_REVA or USE_STM32469I_DISCO_REVB respectively.

@par How to use it ?

In order to make the program work, you must do the following :
- Open your preferred toolchain
- Rebuild all files and load your image into target memory
- Run the example