FT232BM datasheet(8/54 Pages) FTDI

8 / 54 page

DS2232C Version 1.2

Page 8 of 54

FT2232C Dual USB UART / FIFO I.C.

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EEPROM Interface

When used without an external EEPROM the

FT2232C be configured as a USB to dual serial

port device. Adding an external 93C46 (93C56

or 93C66) EEPROM allows each of the chip’s

channels to be independently configured as a

serial UART (232 mode), or a parallel FIFO (245

mode). The external EEPROM is used to enable

the CPU-style FIFO interface, and Fast Opto-

Isolated Serial interface modes. The external

EEPROM can also be used to customise the USB

VID, PID, Serial Number, Product Description

Strings and Power Descriptor value of the

FT2232C for OEM applications. Other parameters

controlled by the EEPROM include Remote Wake

Up, Isochronous Transfer Mode, Soft Pull Down on

Power-Off and USB 2.0 descriptor modes.

The EEPROM should be a 16 bit wide

configuration such as a MicroChip 93LC46B or

equivalent capable of a 1Mb/s clock rate at VCC =

4.35V to 5.25V. The EEPROM is programmable-

on board over USB using a utility program available

from FTDI’s web site (

www.ftdichip.com). This

allows a blank part to be soldered onto the PCB

and programmed as part of the manufacturing and

test process.

If no EEPROM is connected (or the EEPROM

is blank), the FT2232C will default to dual serial

ports. The device use its built-in default VID, PID

Product Description and Power Descriptor Value.

In this case, the device will not have a serial

number as part of the USB descriptor.

FT232BM Datasheet(PDF) 8 Page - Future Technology Devices International Ltd.