Document No.: FT_000288
FT232H SINGLE CHANNEL HI-SPEED USB TO MULTIPURPOSE UART/FIFO IC
Datasheet Version 1.82
Clearance No.: FTDI #199
4.13 FT232H Mode Selection
The FT232H defaults to asynchronous serial interface (UART) mode of operation.
After a reset the required mode is determined by the contents of the external EEPROM which can be
programmed using FT_Prog.
The EEPROM contents determine if the FT232H device is configured as FT232 asynchronous serial
interface, FT245 FIFO interface, CPU-style FIFO interface, FT1248 or Fast Serial Interface.
Following a reset, the EEPROM is read and the FT232H configured for the selected mode. After device
enumeration, the FT_SetBitMode command (refer to D2XX_Programmers_Guide) can be sent to the
USB driver to switch the selected interface into other modes – asynchronous bit-bang, synchronous bit-
bang or MPSSE – if required.
When in FT245 FIFO mode, the FT_SetBitMode command can be used to select Synchronous FIFO
(FT_SetBitMode = 0x40). Note that FT245 FIFO mode must be configured in the EEPROM before
selecting the Synchronous FIFO mode.
The drive strength selection, slew rate and Schmitt input function can also be configured in the EEPROM.
The MPSSE can be configured directly using the D2XX commands. The D2XX_Programmers_Guide is
available from the FTDI website. The application note AN_108 – Command Processor for MPSSE and MCU
Host Bus Emulation Modes gives further explanation and examples for the MPSSE.
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