usb-device implementation for Holtek HT32 microcontrollers.
This project is heavily inspired by the stm32-usbd reference implementation.
It has been primarily developed for, and tested with, the HT32F1yyy family of chips,
but should also work with other Holtek chips that use the same USB peripheral.
This driver is intended for use through a device hal library.
Such hal library should implement UsbPeripheral for the corresponding USB peripheral object.
This trait declares all the peripheral properties that may vary from one device family to the other.
Note that, besides including this library, it is also necessary to make sure that the USB peripheral is enabled, the USB clock has the right frequency (48MHz) and the backup domain is accessible.
See the ht32f1yyy-hal repo for an example of how to use this library.