Hello Ishant,
Based in the excerpt from the USBXpress programming guide, you should be able to:
"The Silicon Laboratories USBXpress Development Kit provides a complete host and device software solution
for
interfacing Silicon Laboratories C8051F32x microcontrollers to the Universal Serial Bus (USB). No USB protocol or
host device driver expertise is required. Instead, a simple, high-level Application Program Interface (API) for both
the host software and device firmware is used to provide complete USB connectivity."
It looks like aa1982 got it working on this post:
usb communication with silicon lab c8051f320And both are using the C8051F32x series controllers, you may want to get in contact with the owner of that thread to see if he encountered any problems.
Xaq