FTDI's FT232R USB UART (4th generation), FT245R USB FIFO (4th generation), FT2232C Dual USB UART/FIFO (3rd generation), FT232BM USB UART (2nd generation) and FT245BM USB FIFO (2nd generation) offer extra functionality, including programmable features, to their predecessors. The programmable features are supported by extensions to the D2XX driver, and the programming interface is exposed by FTD2XX.DLL.
New features include a programmable receive buffer timeout and bit bang mode. The receive buffer timeout is controlled via the latency timer functions FT_GetLatencyTimer and FT_SetLatencyTimer. Bit bang modes and other FT2232C bit modes are controlled via the functions FT_GetBitMode and FT_SetBitMode. Before these functions can be accessed, the device must first be opened. The Win32API function, CreateFile, returns a handle that is used by all functions in the programming interface to identify the device.
Type definitions of the functional parameters and return codes used in the D2XX extended programming interface are contained in the appendix.