Download STM32Cube USB device library

UM1734
5
USB device library overview
USB device library overview
The USB device library is based on the generic USB low level driver. It has been developed
to work in Full speed and High speed mode.
It implements the USB device library machines as defined by Universal Serial Bus
Specification revision 2.0. The library functions are covered by the files located in the Core
folder within the USB device library firmware package (see Figure 5). The USB class
module is the class layer built in compliance with the protocol specification.
Figure 5. USB device library directory structure
5.1
USB device library description
5.1.1
USB device library flow
Handling control endpoint
The USB specification defines four transfer types: control, interrupt, bulk and isochronous.
The USB host sends requests to the device through the control endpoint (in this case,
control endpoint is endpoint 0). The requests are sent to the device as SETUP packets.
These requests can be classified into three categories: standard, class-specific and vendorspecific. Since the standard requests are generic and common to all USB devices, the
library receives and handles all the standard requests on the control endpoint 0.
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