FTDI DEVICE DRIVERS
FTDI make available two drivers, the Virtual COM Port (VCP) driver and the Direct (D2XX) driver. The VCP is generally the simpler to use for applications, whereas the D2XX would be used where an FTDI device implements a board’s USB interface.
Virtual COM Port Driver (VCP)
The VCP driver is used where a standalone microprocessor implements low-level functionality, such as temperature measurement, which a higher-level system uses. The VCP driver emulates a standard serial port such that the USB device may be communicated with as a standard RS232 device. With the VPC driver installed on a target system such as a PC or Compact 7 system, an FTDI module is plugged into the system’s USB host socket via a USB cable. The module’s functionality is then available to an application on the target system as a serial interface via a COM port. The module can implement a protocol for its configuration and status and data transfer as a textual protocol via the serial interface.
Direct Driver (D2XX)
The D2XX driver enables direct access by an end user application to an FTDI USB device via a DLL interface. When installed, a custom driver stream is installed. The download of this driver contains the driver DLL (ftdi_d2xx.dll), the registry file (d2xx.reg in the INF FILEs directory), and the FTDI stream API files that are used with an end-user application. FTD2xx.h is the include file that needs to be referenced by the application; FTD2XX.lib is linked with it; and ftd2XX.dll is ...