138 lines
7.3 KiB
Plaintext
138 lines
7.3 KiB
Plaintext
/**
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@page MSC_Standalone USB Host Mass Storage (MSC) application
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@verbatim
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******************************************************************************
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* @file USB_Host/MSC_Standalone/readme.txt
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* @author MCD Application Team
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* @brief Description of the USB Host MSC 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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Use of the USB host application based on the Mass Storage Class (MSC).
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This is a typical application on how to use the STM32F7xx USB OTG Host peripheral to operate with an USB
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flash disk using the Bulk Only Transfer (BOT) and Small Computer System Interface (SCSI) transparent
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commands combined with a file system FatFs (Middleware component).
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At the beginning of the main program the HAL_Init() function is called to reset all the peripherals,
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initialize the Flash interface and the systick. The user is provided with the SystemClock_Config()
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function to configure the system clock (SYSCLK) to run at 200 Mhz. The Full Speed (FS) USB module uses
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internally a 48-MHz clock which is coming from a specific output of two PLLs: main PLL or PLL SAI.
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In the High Speed (HS) mode the USB clock (60 MHz) is driven by the ULPI.
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When the application is started, the connected USB flash disk device is detected in MSC mode and gets
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initialized. The STM32 MCU behaves as a MSC Host, it enumerates the device and extracts VID, PID,
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manufacturer name, Serial no and product name information and displays it on the LCD screen.
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This application is based on read/write file and explore the USB flash disk content through a MSC routine.
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User can start any operations using User button:
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- "File Operations" operation writes a small text file (less to 1 KB) on the USB flash disk.
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- "Explorer Disk" operation explores the USB flash disk content and displays it on the LCD screen.
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User has to press the User button to display the whole USB flash disk content (recursion level 2).
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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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For more details about the STM32Cube USB Host library, please refer to UM1720
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"STM32Cube USB Host library".
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@par USB Library Configuration
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To select the appropriate USB Core to work with, user must add the following macro defines within the
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compiler preprocessor (already done in the preconfigured projects provided with this application):
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- "USE_USB_HS" when using USB High Speed (HS) Core
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It is possible to fine tune needed USB Host features by modifying defines values in USBH configuration
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file <20>usbh_conf.h<> available under the project includes directory, in a way to fit the application
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requirements, such as:
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0: No debug messages
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1: Only User messages are shown
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2: User and Error messages are shown
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3: All messages and internal debug messages are shown
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By default debug messages are displayed on the debugger IO terminal; to redirect the Library
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messages on the LCD screen, lcd_log.c driver need to be added to the application sources.
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@par Keywords
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Connectivity, USB_Host, USB, MSC, Mass Storage, Full Speed, High Speed, BOT, SCSI, Removable drive, FatFs,
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File system, Write, Read, Format
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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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- USB_Host/MSC_Standalone/Src/main.c Main program
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- USB_Host/MSC_Standalone/Src/STM32F7xx_it.c Interrupt handlers
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- USB_Host/MSC_Standalone/Src/menu.c MSC State Machine
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- USB_Host/MSC_Standalone/Src/usbh_conf.c General low level driver configuration
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- USB_Host/MSC_Standalone/Src/explorer.c Explore the USB flash disk content
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- USB_Host/MSC_Standalone/Src/file_operations.c Write/read file on the disk
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- USB_Host/MSC_Standalone/Src/system_STM32F7xx.c STM32F7xx system clock configuration file
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- USB_Host/MSC_Standalone/Inc/main.h Main program header file
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- USB_Host/MSC_Standalone/Inc/STM32F7xx_it.h Interrupt handlers header file
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- USB_Host/MSC_Standalone/Inc/lcd_log_conf.h LCD log configuration file
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- USB_Host/MSC_Standalone/Inc/STM32F7xx_hal_conf.h HAL configuration file
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- USB_Host/MSC_Standalone/Inc/usbh_conf.h USB Host driver Configuration file
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- USB_Host/MSC_Standalone/Inc/ffconf.h FatFs Module Configuration file
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@par Hardware and Software environment
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- This application runs on STM32F769xx/STM32F779xx devices.
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- This application has been tested with STMicroelectronics STM32F769I-Discovery
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boards and can be easily tailored to any other supported device
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and development board.
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- STM32F769I-Discovery Set-up
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- Plug the USB key into the STM32F769I-Discovery board through 'USB micro A-Male
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to A-Female' cable to the connector:
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- CN15 : to use USB High Speed (HS)
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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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- In the workspace toolbar select the project configuration:
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- STM32F769I-Discovery: to configure the project for STM32F7xx devices using USB OTG HS peripheral
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- Run the application
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*/
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