Silicon Laboratories

This application note is intended for developers creating products based on the CP210x Universal Serial Bus (USB) to universal asynchronous receiver/transmitter (UART) Bridge Controller. It provides information about serial communications and how to obtain the port number for a specific CP210x device. Code samples are provided for opening, closing, configuring, reading, and writing to a COM port. Also included are GetPortNumWinXXXX() functions that can be copied and used to determine the port number on a CP210x device by using its Vendor ID (VID), Product ID (PID), and serial number.