The 2232L is the most recently introduced FTDI chip.

The most basic form of operation is a configurable dual channel version of FTDI’s 232/245 BM devices which convert: one USB port into two serial UART ports, one USB port into two parallel FIFO ports, or one USB port into one serial UART port and one parallel FIFO port.

Each serial/parallel port has the exact same functionality as the FT232BM/FT245BM equivalent chips.

The FT2232C has a more advanced mode of operation called the Multi-Protocol Synchronous Serial Engine (MPSSE!). This controller is built into channel A of the chip and can be used to interface USB to synchronous serial protocol such as JTAG and SPI bus. The chip is fully configurable with an FTDI-command set to provide support for almost any industry-standard or proprietary synchronous serial protocol. MPSSE is the fastest (5.6 Mbit/s) USB to JTAG interface on the market, and we already have much interest and several design wins with major device manufacturers. Further, the FT2232C can also be put into an asynchronous bit bang mode, synchronous bit bang mode, CPU interface mode, MCU host bus emulation mode and fast opto-isolated serial interface mode.

Resources:
FTDI Schematics (Off Site)
FTDI Chip Drivers (Off Site)