110 lines
5.2 KiB
Plaintext
110 lines
5.2 KiB
Plaintext
/**
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@page LibJPEG_Decoding LibJPEG decoding application
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@verbatim
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******************** (C) COPYRIGHT 2016 STMicroelectronics *******************
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* @file LibJPEG/LibJPEG_Decoding/readme.txt
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* @author MCD Application Team
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* @brief Description of the LibJPEG decoding application.
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******************************************************************************
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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 Application Description
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This application demonstrates how to read jpeg file from SDCard memory, decode it
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and display the final BMP image on the LCD.
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The JPEG images should be copied at the micro SD card root.
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The images must have the following properties:
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- named as "image.jpg"
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- 320*240 size
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Unomment "SWAP_RB" define in "main.h" file if the displayed image colors
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are inverted
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The image transferring to the LCD_FRAME_BUFFER can be done with two ways;
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with CPU or with DMA2D. In main.h file, uncomment "USE_DMA2D" define for DMA2D
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transfer. Otherwise, transfer is made by CPU.
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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 needs 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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@note The STM32F7xx devices can reach a maximum clock frequency of 216MHz but as this application uses SDRAM,
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the system clock is limited to 200MHz. Indeed proper functioning of the SDRAM is only guaranteed
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at a maximum system clock frequency of 200MHz.
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@par Keywords
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Display, Graphic, LibJPEG, Decoding, Flash memory, DMA2D, ARGB8888, LCD, RGB, BMP, JPG, SD Card
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@Note<74>If the user code size exceeds the DTCM-RAM size or starts from internal cacheable memories (SRAM1 and SRAM2),that is shared between several processors,
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<20><><EFBFBD><EFBFBD><EFBFBD>then it is highly recommended to enable the CPU cache and maintain its coherence at application level.
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<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>The address and the size of cacheable buffers (shared between CPU and other masters) must be properly updated to be aligned to cache line size (32 bytes).
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@Note It is recommended to enable the cache and maintain its coherence, but depending on the use case
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<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> It is also possible to configure the MPU as "Write through", to guarantee the write access coherence.
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<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>In that case, the MPU must be configured as Cacheable/Bufferable/Not Shareable.
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<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Even though the user must manage the cache coherence for read accesses.
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<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Please refer to the AN4838 <20>Managing memory protection unit (MPU) in STM32 MCUs<55>
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<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Please refer to the AN4839 <20>Level 1 cache on STM32F7 Series<65>
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@par Directory contents
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- LibJPEG/LibJPEG_Decoding/Inc/main.h Main program header file
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- LibJPEG/LibJPEG_Decoding/Inc/stm32f7xx_it.h Interrupt handlers header file
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- LibJPEG/LibJPEG_Decoding/Inc/stm32f7xx_hal_conf.h HAL Configuration file
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- LibJPEG/LibJPEG_Decoding/Inc/ffconf.h FAT file system module configuration file
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- LibJPEG/LibJPEG_Decoding/Inc/decode.h decoder header file
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- LibJPEG/LibJPEG_Decoding/Inc/jmorecfg.h Lib JPEG configuration file (advanced configuration).
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- LibJPEG/LibJPEG_Decoding/Inc/jconfig.h Lib JPEG configuration file.
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- LibJPEG/LibJPEG_Decoding/Inc/jdata_conf.h Write/Read methods definition
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- LibJPEG/LibJPEG_Encoding/Src/sd_diskio.h SD diskio header file
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- LibJPEG/LibJPEG_Decoding/Src/main.c Main program
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- LibJPEG/LibJPEG_Decoding/Src/stm32f7xx_it.c Interrupt handlers
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- LibJPEG/LibJPEG_Decoding/Src/system_stm32f7xx.c STM32F7xx system clock configuration file
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- LibJPEG/LibJPEG_Decoding/Src/decode.c decoder file
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- LibJPEG/LibJPEG_Encoding/Src/jdata_conf.c Write/Read methods definition
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- LibJPEG/LibJPEG_Encoding/Src/sd_diskio.c SD diskio file
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@par Hardware and Software environment
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- This example runs on STM32F756xx/STM32F746xx devices.
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- This example has been tested with STMicroelectronics STM327x6G-EVAL
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evaluation boards and can be easily tailored to any other supported device
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and development board.
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- STM327x6G-EVAL Set-up
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- Connect a uSD Card to the MSD connector (CN16).
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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 application
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*/
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