CP2108 Datasheet, PDF (27/30 Pages) Silicon Laboratories – SINGLE-CHIP USB-TO-QUAD-UART BRIDGE

CP2108
The internal EEPROM is programmed using the USB interface. This allows the OEM's USB configuration data and
serial number to be written to the CP2108 on-board during the manufacturing and testing process. A stand-alone
utility for programming the internal EEPROM is available from Silicon Labs. A library of routines provided in the
form of a Windows® DLL is also available. This library can be used to integrate the EEPROM programming step
into custom software used by the OEM to streamline testing and serial number management during manufacturing.
USB descriptors can be locked to prevent future modification.
10. CP2108 Device Drivers
The device driver available for CP2108 is the Virtual COM Port (VCP) driver. The latest drivers are available at
www.silabs.com/mcudownloads.
10.1. Virtual COM Port Drivers
The CP2108 Virtual COM Port (VCP) device drivers allow a CP2108-based device to appear to the PC's
application software as four COM ports. Application software running on the PC accesses the CP2108-based
device as it would access four standard hardware COM ports. However, actual data transfer between the PC and
the CP2108 device is performed over the USB interface. Therefore, existing COM port applications may be used to
transfer data via the USB to the CP2108-based device without modifying the application. See application note
“AN197: Serial Communications Guide for the CP210x” for example code for interfacing to a CP2108 using the
VCP drivers.
10.2. Driver Customization
In addition to customizing the device as described in Section 7, the drivers and the drivers installation package can
be also be customized. See application note “AN220: USB Driver Customization” for more information on
generating customized VCP drivers.
Important Note: The VID/PID in the drivers must match the VID/PID in the device for the drivers to load properly
when the device is connected to the PC.
10.3. Driver Certification
The default drivers for the CP2108 are Microsoft Windows Hardware Quality Labs (WHQL) certified. The
certification means that the drivers have been tested by Microsoft and their latest operating systems will allow the
drivers to be installed without any warnings or errors.
The customized drivers that are generated using the AN220 software are not automatically certified. To become
certified, they must go first through the Microsoft Driver Reseller submission process. Contact Silicon Labs support
for assistance with this process.
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