87 lines
3.8 KiB
Plaintext
87 lines
3.8 KiB
Plaintext
/**
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@page DMA_FLASHToRAM DMA example
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@verbatim
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******************** (C) COPYRIGHT 2016 STMicroelectronics *******************
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* @file Examples_MIX/DMA/DMA_FLASHToRAM/readme.txt
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* @author MCD Application Team
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* @brief Description of the DMA example.
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******************************************************************************
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* @attention
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*
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* <h2><center>© Copyright (c) 2016 STMicroelectronics.
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* All rights reserved.</center></h2>
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*
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* This software component is licensed by ST under BSD 3-Clause license,
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* the "License"; You may not use this file except in compliance with the
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* License. You may obtain a copy of the License at:
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* opensource.org/licenses/BSD-3-Clause
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*
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******************************************************************************
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@endverbatim
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@par Example Description
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How to use a DMA to transfer a word data buffer from Flash memory to embedded
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SRAM through the STM32F1xx DMA HAL and LL API. The LL API is used for
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performance improvement.
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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 72 MHz.
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DMA1_Channel1 is configured to transfer the contents of a 32-word data
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buffer stored in Flash memory to the reception buffer declared in RAM.
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The start of transfer is triggered by LL API. DMA1_Channel1 memory-to-memory
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transfer is enabled. Source and destination addresses incrementing is also enabled.
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The transfer is started by setting the channel enable bit for DMA1_Channel1.
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At the end of the transfer a Transfer Complete interrupt is generated since it
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is enabled and the callback function (customized by user) is called.
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Board's LEDs can be used to monitor the transfer status:
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- LED2 is ON when the transfer is complete (into the Transfer Complete interrupt
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routine).
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- LED2 is Toggled with a period of 200 ms when there is a transfer error
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- LED2 is Toggled with a period of 1000 ms when Error_Handler is called
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It is possible to select a different channel for the DMA transfer
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example by modifying defines values in the file main.h.
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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 Directory contents
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- DMA/DMA_FLASHToRAM/Src/system_stm32f1xx.c STM32F1xx system clock configuration file
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- DMA/DMA_FLASHToRAM/Src/stm32f1xx_it.c Interrupt handlers
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- DMA/DMA_FLASHToRAM/Src/main.c Main program
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- DMA/DMA_FLASHToRAM/Inc/stm32f1xx_hal_conf.h HAL Configuration file
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- DMA/DMA_FLASHToRAM/Inc/stm32f1xx_it.h Interrupt handlers header file
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- DMA/DMA_FLASHToRAM/Inc/main.h Main program header file
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@par Hardware and Software environment
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- This example runs on STM32F103xB Devices.
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- This example has been tested with STMicroelectronics STM32F103RB-Nucleo
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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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* <h3><center>© COPYRIGHT STMicroelectronics</center></h3>
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*/
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