Copyright © Future Technology Devices International Limited

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Document Reference No.: FT_000188

TTL TO USB SERIAL CONVERTER GENERIC CABLES Datasheet

Version 1.4

Clearance No.: FTDI# 129

3 Features of FT232R applicable toTTL-232RG Generic Cables

The TTL-232RG generic cables use FTDI’s FT232RQ USB to serial IC device. This section summarises the

key features of the FT232RQ which apply to the TTL-232RG USB to serial TTL converter cables. For

further details, and a full features and enhancements description consult the FT232R datasheet, this is

available from http://www.ftdichip.com.

Internal EEPROM. The internal EEPROM in each cable is used to store USB Vendor ID (VID), Product ID

(PID), device serial number, product description string and various other USB configuration descriptors.

Each cable is supplied with the internal EEPROM pre-programmed as described in Appendix A - Cable

EEPROM Configuration. A user area of the internal EEPROM is available to system designers to allow

storing additional data. The internal EEPROM descriptors can be programmed in circuit, over USB without

any additional voltage requirement. It can be programmed using the FTDI utility software called MPROG,

which can be downloaded from FTDI Utilities on the FTDI website (www.ftdichip.com).

Lower Operating and Suspend Current. The FT232R has a low 15mA operating supply current and a

very low USB suspend current of approximately 70μA. (Note that during suspend mode, the current

drawn by application should not exceed 2.5mA to remain USB compliant)

Low USB Bandwidth Consumption. The USB interface of the FT232R, and therefore the TTL-232RG

cables has been designed to use as little as possible of the total USB bandwidth available from the USB

host controller.

High Output Drive Option. The UART interface I/O pins on the TTL-232RG cables (RXD, TXD, RTS#,

and CTS#) can be configured to use the FT232R’s high output drive option. This option allows the FT232R

I/O pins to drive up to three times the standard signal drive level. This allows multiple devices to be

driven, or devices that require greater signal drive strength to be interfaced to the cables. This option is

enabled in the internal EEPROM.

UART Pin Signal Inversion. The sense of each of the eight UART signals can be individually inverted by

configuring options in the internal EEPROM. For example CTS# (active low) can be changed to CTS

(active high), or TXD can be changed to TXD#.

FTDIChip-ID™. The FT232R includes the FTDIChip-ID™ security dongle feature. This FTDIChip-ID™

feature allows a unique number to be burnt into each cable during manufacture. This number cannot be

reprogrammed. This number is only readable over USB can be used to form the basis of a security dongle

which can be used to protect any customer application software being copied. This allows the possibility

of using the TTL-232RG cables as a dongle for software licensing. Further to this, a renewable license

scheme can be implemented based on the FTDIChip-ID™ number when encrypted with other information.

This encrypted number can be stored in the user area of the FT232R internal EEPROM, and can be

decrypted, then compared with the protected FTDIChip-ID™ to verify that a license is valid. Web based

applications can be used to maintain product licensing this way. An application note, AN232R-02,

available from FTDI website (www.ftdichip.com) describes this feature.

Improved EMI Performance. The TTL-232RG cables are FCC and CE certified.

Extended Operating Temperature Range - The TTL-232RG generic cables are capable of operating

over an extended temperature range of -40º to +85º C thus allowing them to be used in automotive or

industrial applications.