Description
SiUSBXp.dll is a DLL file that is associated with Silicon Laboratories USBXpress development kit.
This DLL file provides a set of functions that are used by USBXpress applications to communicate with Silicon Laboratories' USBXpress devices, including USB-to-serial bridges and other USB-based peripherals.
Solution
If you search the last version of this file, the installer can be found here:
https://www.silabs.com/products/development-tools/software/direct-access-drivers
This installer contains SiUSBXp.dll, SiUSBXp.h as well as other files
After installation, the USBXpress SDK files will be located at this default location:
C:\SiliconLabs\MCU\USBXpress_SDK