UM1021 - STMicroelectronics

USB device library UM1021

Additional functions could be added as the IsoINIncomplete and IsoOUTIncomplete could be eventually used to handle incomplete isochronous transfers (for more information, refer to the USB audio device example). EP0_TxSent and EP0_RxReady could be eventually used when the application needs to handle events occurring before the Zero

Length Packets (see the DFU example).

Figure 13.

Folder organization

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For each example, the source folder is split into src (sources) and inc (includes).

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The sources directory includes the following files:

app.c: contains the main function

stm32fxxx_it.c: contains the system interrupt handlers

system_stm32fxxx.c: system clock configuration file for STM32Fxxx devices.

usb_bsp.c: contains the function implementation (declared in the usb_bsp.h in the USB

OTG low level driver) to initialize the GPIO for the core, time delay methods and interrupts enabling/disabling process.

● usbd_usr: contains the function implementation (declared in the usbd_usr.h in the USB library) to handle the library events from user layer (event messages).

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usbd_desc.c: This file is provided within USB Device examples and implements callback bodies. This file offers a set of functions used to change the device and string descriptors at application runtime.

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The includes directory contains the following files:

stm32fxxx_it.h: header file of the stm32fxxx_it.c file

usb_conf.h: configuration files for the USB OTG low level driver.

usbd_conf.h: configuration files for the USB device library.

Doc ID 18153 Rev 3