ft8u232am Future Technology Devices International Ltd., ft8u232am Datasheet - Page 4

• Manufacturer Part Number: ft8u232am
• Description: U-uart - Usb Ultrabaud Data Transfer Ic With Rs232 / Rs422 And Cpu I/f Options
• Manufacturer: Future Technology Devices International Ltd.

Dual Port RX Buffer ( 384 bytes )
Data from the UART receive register is stored in the Dual Port RX buffer prior to being removed by the
SIE on a USB request for data from the device data in endpoint.
UART FIFO Controller
The UART FIFO controller handles the transfer of data between the Dual Port RX and TX buffers and the
UART transmit and receive registers.
UART
The UART performs asynchronous 7 / 8 bit Parallel to Serial and Serial to Parallel conversion of the data
on the RS232 ( RS422 and RS485 ) interface. Control signals supported by the UART include RTS, CTS,
DSR , DTR, DCD and RI. The UART provides a transmitter enable control signal ( TXDEN ) to assist
with interfacing to RS485 transceivers.
Baud Rate Generator
The Baud Rate Generator provides a x16 clock input to the UART from the 48MHz reference clock and
consists of a 14 bit prescaler and 2 register bits which provide fine tuning of the baud rate ( e.g. to divide
by 2.5 ). This determines the Baud Rate of the UART which is programmable from 300 baud to 2 million
baud. For more details please contact FTDI.
EEPROM Interface
Though the FT8U232AM will work without the optional EEPROM, an external 93C46 EEPROM can be
used to customise the USB VID, PID, Serial Number and Strings of the FT8U232AM for OEM
applications. The EEPROM is also required for applications where multiple FT8U232AM’s are connected
to a single PC as the drivers rely on a unique serial number for each device to bind a unique virtual COM
port to each individual device.
Future Technology Devices Intl.
FT8U232AM Preliminary Information Rev 0.8 – Subject to Change