Is the USBXpress firmware or driver source code available?
USBXpress is designed to make programming with USB simple. The USBXpress API can be used to perform all USB tasks in most systems. If your system requires capabilities beyond which USBXpress can provide, the Silicon Labs IDE includes several USB examples with full source code that can be used for development, like the USB Bulk, USB Interrupt, and HID Class examples. After installing the Silicon Labs IDE (from the CD or the web), these examples can be found in the installation directory.
The source code for the USBXpress driver is not available, for either CP210x or C8051F32x / C8051F34x devices.
The source code for the latest USBXpress firmware library is available under a Software License Agreement. Please contact MCU support using the web support form (https://www.silabs.com/support/pages/contacttechnicalsupport.aspx) for more specifics on the Software License Agreement. Firmware will be released under SLA at our discretion, typically only when there is a need to implement something we do not support.