UMFT201XA-01 Datasheet, PDF (10/28 Pages) List of Unclassifed Manufacturers – Introducing the FT-X Series of USB2.0 Full Speed Peripheral Solutions

FTDI Drivers Architecture
FTDI provides two alternative software
interfaces for USB controllers.
COM Port Application
One interface provides a Virtual COM Port
(VCP) which appears to the system as a
legacy COM port. Legacy applications
should work with VCP drivers with minimal
modification.
D2XX API
The second interface, D2XX, is provided via
a proprietary DLL (FTD2XX.DLL). The D2XX
interface provides special functions to
optimize performance and improve
flexibility.
D2XX API
Application
FTD2XX.DLL
Win32 COMM API
Application
FTSER2K.SYS
D2XX Interface
FTDIBUS Class Interface
Combined Driver
USB Stack