Unfortunately, SiLabs web has little information on USB-serial application using 'F32x. Maybe because they are also selling USB-serial chips, CP210x.

To make an USB-serial converter on 'F32x,
a) USBXpress
USBXpress consists of a firmware library, device driver and DLL for Windows. It capsulates most of USB complexity. Adding UART handler and connecting it to USBXpress library, you can make USB-serial converter easily.

However, If you want to control baudrate or handshake signals from the PC application, you'll face another problem, because USBXpress supplies only single IN and single OUT communication channel: no control channel.

b) SiLabs USB_bulk example
USB_bulk example is a demonstration of USB mini-FLASH storage (not disk ;-) ). Replacing FLASH storage function to UART handling on the firmware, you can make an USB-serial converter. You can use complicated enumeration procedure as it is.

If you want to control baudrate or handshake signals, you need to implement vendor request or another interrupt IN/OUT endpoint. Actually, these implementation is a little hard for USB beginners, but it is a good practice to master USB.

c) CDC (Communication Device Class)
Above implementation using USB_bulk can be expanded to CDC implementation. But it is not a beginner's project.

USBXpress and SiLabs USB examples (included in SiLabs IDE update) are downloaded from "Software Downloads" page
http://www2.silabs.com/tgwWebApp...nloads.htm


Unless you plan this 'F320 project for your USB study, I recommend you to use an USB-serial chip instead. FTDI, SiLabs and Prolific are well-known manufacturer.
SiLabs chip is good in fabrication; least external parts. But their drivers are inferior than FTDI on its function, stability, multi-OS support and distribution, that is, entirely ;-)

FTDI
http://www.ftdichip.com/FTProducts.htm

SiLabs
http://www.silabs.com/tgwWebApp...erface.htm

Prolific
http://www.prolific.com.tw/eng/Produ....asp?ID=10

Tsuneo