STM32CubeF7/Projects/STM32756G_EVAL/Applications/USB_Device/MSC_Standalone

/**
  @page MSC_Standalone USB Device Mass Storage (MSC) application
  
  @verbatim
  ******************** (C) COPYRIGHT 2016 STMicroelectronics *******************
  * @file    USB_Device/MSC_Standalone/readme.txt 
  * @author  MCD Application Team
  * @brief   Description of the USB Device MSC application.
  ******************************************************************************
  *
  * @attention
  *
  * Copyright (c) 2017 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  @endverbatim

@par Application Description

Use of the USB device application based on the Mass Storage Class (MSC).

This is a typical application on how to use the STM32F7x6 USB OTG Device peripheral to communicate with a PC
Host using the Bulk Only Transfer (BOT) and Small Computer System Interface (SCSI) transparent commands, 
while the microSD card is used as storage media. The STM32 MCU is enumerated as a MSC device using the 
native PC Host MSC driver to which the STM327x6G-EVAL board is connected.

At the beginning of the main program the HAL_Init() function is called to reset all the peripherals,
initialize the Flash interface and the systick. The user is provided with the SystemClock_Config()
function to configure the system clock (SYSCLK) to run at 216 MHz. The Full Speed (FS) USB module uses
internally a 48-MHz clock which is coming from a specific output of two PLLs: main PLL or PLL SAI.
In the High Speed (HS) mode the USB clock (60 MHz) is driven by the ULPI.

The 48 MHz clock for the USB FS can be derived from one of the two following sources:
  – PLL clock (clocked by the HSE): If the USB uses the PLL as clock source, the PLL VCO clock must be programmed
    to output 432 MHz frequency (USBCLK = PLLVCO/PLLQ).
  – PLLSAI clock (clocked by the HSE): If the USB uses the PLLSAI as clock source, the PLLSAI VCO clock must be programmed
    to output 384 MHz frequency (USBCLK = PLLSAIVCO/PLLSAIP).

When the application is started, the user has just to plug the USB cable into a PC host and the device 
is automatically detected. A new removable drive appears in the system window and write/read/format 
operations can be performed as with any other removable drive.

@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 needs to ensure that the SysTick time base is always set to 1 millisecond
      to have correct HAL operation.
      
For more details about the STM32Cube USB Device library, please refer to UM1734 
"STM32Cube USB Device library".
      

@par USB Library Configuration

To select the appropriate USB Core to work with, user must add the following macro defines within the
compiler preprocessor (already done in the preconfigured projects provided with this application):
      - "USE_USB_HS" when using USB High Speed (HS) Core
      - "USE_USB_FS" when using USB Full Speed (FS) Core 
      - "USE_USB_HS" and "USE_USB_HS_IN_FS" when using USB High Speed (HS) Core in FS mode

@par Keywords

Connectivity, USB_Device, USB, MSC, Mass Storage, Full Speed, High Speed, BOT, SCSI, SD Card, Removable drive,
Write, Read, Format

@Note 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,
      then it is highly recommended to enable the CPU cache and maintain its coherence at application level.
      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).

@Note It is recommended to enable the cache and maintain its coherence, but depending on the use case
      It is also possible to configure the MPU as "Write through", to guarantee the write access coherence.
      In that case, the MPU must be configured as Cacheable/Bufferable/Not Shareable.
      Even though the user must manage the cache coherence for read accesses.
      Please refer to the AN4838 “Managing memory protection unit (MPU) in STM32 MCUs”
      Please refer to the AN4839 “Level 1 cache on STM32F7 Series”

@par Directory contents

  - USB_Device/MSC_Standalone/Src/main.c                  Main program
  - USB_Device/MSC_Standalone/Src/system_stm32f7xx.c      STM32F7xx system clock configuration file
  - USB_Device/MSC_Standalone/Src/stm32f7xx_it.c          Interrupt handlers
  - USB_Device/MSC_Standalone/Src/usbd_conf.c             General low level driver configuration
  - USB_Device/MSC_Standalone/Src/usbd_desc.c             USB device MSC descriptor
  - USB_Device/MSC_Standalone/Src/ubsd_storage.c          Media Interface Layer
  - USB_Device/MSC_Standalone/Inc/main.h                  Main program header file
  - USB_Device/MSC_Standalone/Inc/stm32f7xx_it.h          Interrupt handlers header file
  - USB_Device/MSC_Standalone/Inc/stm32f7xx_hal_conf.h    HAL configuration file
  - USB_Device/MSC_Standalone/Inc/usbd_conf.h             USB device driver Configuration file
  - USB_Device/MSC_Standalone/Inc/usbd_desc.h             USB device MSC descriptor header file
  - USB_Device/MSC_Standalone/Inc/ubsd_storage.h          Media Interface Layer header file   

	
@par Hardware and Software environment

  - This application runs on STM32F756xx/STM32F746xx devices.
    
  - This application has been tested with STMicroelectronics STM327x6G-EVAL RevB
    evaluation boards and can be easily tailored to any other supported device 
    and development board.

  - STM327x6G-EVAL RevB Set-up
    - Insert a microSD card into the STM327x6G_EVAL uSD slot (CN16)
    - Connect the STM327x6G_EVAL board to the PC through 'USB micro A-Male 
      to A-Male' cable to the connector:
      - CN8 : to use USB High Speed (HS) 
      - CN13: to use USB Full Speed (FS)
      - CN14: to use USB HS-IN-FS.
              Note that some FS signals are shared with the HS ULPI bus, so some PCB rework is needed.
              For more details, refer to section "USB OTG2 HS & FS" in STM327x6G_EVAL Evaluation Board 
              User Manual.
        @note Make sure that :
         - jumper JP8 must be removed when using USB OTG FS
            
@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
 - In the workspace toolbar select the project configuration:
   - STM327x6G-EVAL_USBH-HS: to configure the project for STM32F7x6 devices using USB OTG HS peripheral
   - STM327x6G-EVAL_USBH-FS: to configure the project for STM32F7x6 devices using USB OTG FS peripheral
   - STM327x6G-EVAL_USBH-HS-IN-FS: to configure the project for STM32F7x6 devices and use USB OTG HS 
                                   peripheral In FS (using embedded PHY).
 - Run the application
 

 */