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99 lines
4.5 KiB
Plaintext
99 lines
4.5 KiB
Plaintext
/**
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@page DMA2D_MemToMemWithLCD DMA2D Memory to Memory with LCD example
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@verbatim
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******************** (C) COPYRIGHT 2017 STMicroelectronics *******************
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* @file DMA2D/DMA2D_MemToMemWithLCD/readme.txt
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* @author MCD Application Team
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* @brief Description of the DMA2D Memory to Memory with LCD example.
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******************************************************************************
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* @attention
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*
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* Copyright (c) 2017 STMicroelectronics.
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* All rights reserved.
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*
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* This software is licensed under terms that can be found in the LICENSE file
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* in the root directory of this software component.
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* If no LICENSE file comes with this software, it is provided AS-IS.
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*
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******************************************************************************
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@endverbatim
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@par Example Description
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This example provides a description of how to configure DMA2D peripheral in
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Memory_to_Memory transfer mode and display the result on LCD.
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The source buffer in format ARGB4444 and size 150x150 located in Flash is copied in Memory to Memory mode
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by the DMA2D in SRAM Destination buffer of same size and format.
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This SRAM buffer is then displayed by the LTDC centered on LCD screen.
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At the beginning of the main program the HAL_Init() function is called to reset
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all the peripherals, initialize the Flash interface and the systick.
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Then the SystemClock_Config() function is used to configure the system
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clock (SYSCLK) to run at 180 MHz.
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In this basic example the goal is to explain the different fields of the DMA2D
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structure in the case of Memory_to_Memory transfer mode.
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After DMA2D configuration, the data transfer Memory to Memory is performed from Flash memory to
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SRAM. Then the LTDC is configured to display obtained DMA2D output buffer in SRAM on LCD.
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(more details about LCD configuration in LCD examples)
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=> Output offset is the number of pixel to be skipped after each transferred line
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how to calculate the size of the transferred data ?
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=> selected color mode gives the number of bits per pixel and we have
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(ARGB4444 => 16bits/pixel) the number of pixel per line and the number of line,
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therefore :
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data_size = (bits per pixel) X (pixel per line + output offset) X (number of line)
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STM32469I-EVAL boards LEDs can be used to monitor the transfer status:
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- LED1 is ON when the DMA2D transfer is complete.
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- LED2 is ON when there is a DMA2D transfer error.
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- LED3 is ON when there is an error in LTDC transfer/Init process.
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@note Care must be taken when using HAL_Delay(), this function provides accurate delay (in milliseconds)
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based on variable incremented in SysTick ISR. This implies that if HAL_Delay() is called from
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a peripheral ISR process, then the SysTick interrupt must have higher priority (numerically lower)
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than the peripheral interrupt. Otherwise the caller ISR process will be blocked.
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To change the SysTick interrupt priority you have to use HAL_NVIC_SetPriority() function.
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@note The application need to ensure that the SysTick time base is always set to 1 millisecond
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to have correct HAL operation.
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@par Keywords
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Display, Graphic, DMA2D, LCD, SRAM, ARGB4444, Blending, Memory to memory, LTDC, Pixel
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@par Directory contents
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- DMA2D/DMA2D_MemToMemWithLCD/Inc/main.h Main configuration file
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- DMA2D/DMA2D_MemToMemWithLCD/Inc/stm32f4xx_it.h Interrupt handlers header file
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- DMA2D/DMA2D_MemToMemWithLCD/Inc/stm32f4xx_hal_conf.h HAL configuration file
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- DMA2D/DMA2D_MemToMemWithLCD/Inc/ARGB4444_150x150.h Texture in Flash to be transferred by DMA2D in SRAM
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- DMA2D/DMA2D_MemToMemWithLCD/Src/main.c Main program
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- DMA2D/DMA2D_MemToMemWithLCD/Src/stm32f4xx_it.c Interrupt handlers
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- DMA2D/DMA2D_MemToMemWithLCD/Src/stm32f4xx_hal_msp.c HAL MSP module
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- DMA2D/DMA2D_MemToMemWithLCD/Src/system_stm32f4xx.c STM32F4xx system clock configuration file
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@par Hardware and Software environment
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- This example runs on STM32F469xx/STM32F479xx devices.
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- This example has been tested and validated with STMicroelectronics STM32469I-EVAL RevC
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evaluation board and can be easily tailored to any other supported device
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and development board.
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@par How to use it ?
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In order to make the program work, you must do the following :
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- Open your preferred toolchain
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- Rebuild all files and load your image into target memory
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- Run the example
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*/
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