The FT2232C device contains FTDI's multi-protocol synchronous serial engine (MPSSE) controller which may be used to interface to many popular synchronous serial protocols including JTAG, SPI and I2C.
The FTCJTAG DLL has been created to allow application developers to use the FT2232C to create a USB to Joint Test Action Group (JTAG) protocol interface without any knowledge of the MPSSE command set. All of the functions in FTCJTAG.DLL can be replicated using calls to FTD2XX.DLL and sending the appropriate commands to the MPSSE as per application note .
The latest version of FTDI's FTCD2XX drivers must be installed to use FTCJTAG.DLL as several calls are made to a new version of FTD2XX.DLL. The MPSSE is available through channel A of the FT2232C device only; channel B does not support the MPSSE. Channel B may be controlled independently using FTDI's FTCD2XX drivers while channel A is being used for JTAG communication.
This document lists all of the functions available in FTCJTAG.DLL.
The FTCJTAG DLL can be downloaded from the page of the in the area of the site.