FTDIChip UM232R User Manual

™

Future Technology Devices International Ltd.

UM232R USB- Serial UART

Development Module

Incorporating Clock Generator Output

and FTDIChip-ID™ Security Dongle

The UM232R is a development module which uses FTDI’s FT232RL, the latest device to be added to FTDI’s range of

USB UART interface Integrated Circuit Devices.

The FT232RL is a USB to serial UART interface with optional clock generator output, and the new FTDIChip-ID™

security dongle feature. In addition, asynchronous and synchronous bit bang interface modes are available. USB to

serial interface designs using the FT232RL have been further simpliﬁed by fully integrating the external EEPROM,

clock circuit and USB resistors onto the device.

The FT232RL adds two new functions compared with its predecessors, effectively making it a “3-in-1” chip for some

application areas. The internally generated clock (6MHz, 12MHz, 24MHz, and 48MHz) can be brought out of the

device and used to drive a microcontroller or external logic. A unique number (the FTDIChip-ID™) is burnt into the

device during manufacture and is readable over USB, thus forming the basis of a security dongle which can be used

to protect customer application software from being copied.

The UM232R is supplied on a PCB which is designed to plug into a standard 15.0mm (0.6” ) wide 24 pin DIP socket.

All components used, including the FT232RL are Pb-free (RoHS compliant).

1. Features

1.1 Hardware Features

• Single chip USB to asynchronous serial data transfer interface.

• Entire USB protocol handled on the chip - No USB-speciﬁc ﬁrmware programming required.

• UART interface support for 7 or 8 data bits, 1 or 2 stop bits and odd / even / mark / space / no parity.

• Fully assisted hardware or X-On / X-Off software handshaking.

• Data transfer rates from 300 baud to 3 Megabaud (RS422 / RS485 and at TTL levels) and 300 baud to 1 Megabaud (RS232).

• FTDI’s royalty-free VCP and D2XX drivers eliminate the requirement for USB driver development in most cases.

• In-built support for event characters and line break condition.

• New USB FTDIChip-ID™ feature.

• New conﬁgurable CBUS I/O pins.

• Auto transmit buffer control for RS485 applications.

• Transmit and receive LED drive signals.

• New 48MHz, 24MHz,12MHz, and 6MHz clock

output signal Options for driving external MCU or FPGA.

• FIFO receive and transmit buffers for high data throughput.

• Adjustable receive buffer timeout.

• Synchronous and asynchronous bit bang mode

interface options with RD# and WR# strobes.

• New CBUS bit bang mode option.

• Integrated 1024 bit internal EEPROM for storing

USB VID, PID, serial number and product description strings, and CBUS I/O conﬁguration.

• Device supplied preprogrammed with unique USB serial number.

1.2 Driver Support

Royalty-Free VIRTUAL COM PORT (VCP) DRIVERS for...

• Windows 98, 98SE, ME, 2000, Server 2003, XP.

• Windows Vista / Longhorn*

• Windows XP 64-bit.*

• Windows XP Embedded.

• Windows CE.NET 4.2 & 5.0

• MAC OS 8 / 9, OS-X

• Linux 2.4 and greater

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• Support for USB suspend and resume.

• Support for bus powered, self powered, and high-

power bus powered USB conﬁgurations.

• On board jumper allows for selection of USB bus powered supply or self powered supply.

• Integrated 3.3V level converter for USB I/O.

• Integrated level converter on UART and CBUS for

interfacing to 5V - 1.8V Logic.

• On board jumper allows for selection of UART and CBUS interface IO voltage.

• True 5V / 3.3V / 2.8V / 1.8V CMOS drive output and TTL input.

• High I/O pin output drive option.

• Integrated USB resistors.

• Integrated power-on-reset circuit.

• Fully integrated clock - no external crystal,

oscillator, or resonator required.

• Fully integrated AVCC supply ﬁltering - No separate AVCC pin and no external R-C ﬁlter required.

• UART signal inversion option.

• USB bulk transfer mode.

• 3.3V to 5.25V Single Supply Operation.

• Low operating and USB suspend current.

• Low USB bandwidth consumption.

• UHCI / OHCI / EHCI host controller compatible

• USB 2.0 Full Speed compatible.

• -40°C to 85°C extended operating temperature

range.

• Supplied in PCB designed to ﬁt a standard 15.0mm (0.6”) wide 24 pin DIP socket. Pins are on a

2.60mm (0.1”) pitch.

• On board USB ‘B’ socket allows module to be connected to a PC via a standard A to B USB cable.

Royalty-Free D2XX Direct Drivers (USB Drivers + DLL S/W Interface)

• Windows 98, 98SE, ME, 2000, Server 2003, XP.

• Windows Vista / Longhorn*

• Windows XP 64-bit.*

• Windows XP Embedded.

• Windows CE.NET 4.2 & 5.0

• Linux 2.4 and greater

The drivers listed above are all available to download for free from the FTDI website. Various 3rd Party Drivers are also available for various other operating systems - see the FTDI website for details.

* Currently Under Development. Contact FTDI for availability.

1.3 Typical Applications

• USB to RS232 / RS422 / RS485 Converters

• Upgrading Legacy Peripherals to USB

• Cellular and Cordless Phone USB data transfer

cables and interfaces

• Interfacing MCU / PLD / FPGA based designs to USB

• USB Audio and Low Bandwidth Video data transfer

• PDA to USB data transfer

• USB Smart Card Readers

• USB Instrumentation

UM232R USB-Serial UART Development Module Datasheet Version 1.02 © Future Technology Devices International Ltd. 2005

• USB Industrial Control

• USB MP3 Player Interface

• USB FLASH Card Reader / Writers

• Set Top Box PC - USB interface

• USB Digital Camera Interface

• USB Hardware Modems

• USB Wireless Modems

• USB Bar Code Readers

• USB Software / Hardware Encryption Dongles

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2. FT232RL Features and Enhancements

2.1 Key Features

This section summarises the key features and enhancements of the FT232RL IC device which is used on the UM232R Module. For further details, consult the FT232R datasheet, which is available from the FTDI website.

Integrated Clock Circuit - Previous generations of FTDI’s USB UART devices required an external crystal or ceramic resonator. The clock circuit has now been integrated onto the device meaning that no crystal or ceramic resonator is required. However, if required, an external 12MHz crystal can be used as the clock source.

Integrated EEPROM - Previous generations of FTDI’s USB UART devices required an external EEPROM if the device were to use USB Vendor ID (VID), Product ID (PID), serial number and product description strings other than the default values in the device itself. This external EEPROM has now been integrated onto the FT232R chip meaning that all designs have the option to change the product description strings. A user area of the internal EEPROM is available for storing additional data. The internal EEPROM is programmable in circuit, over USB without any additional voltage requirement.

Preprogrammed EEPROM - The FT232R is supplied with its internal EEPROM preprogrammed with a serial number which is unique to each individual device. This, in most cases, will remove the need to program the device EEPROM.

Integrated USB Resistors - Previous generations of FTDI’s USB UART devices required two external series resistors on the USBDP and USBDM lines, and a 1.5 kΩ pull up resistor on USBDP. These three resistors have now been integrated onto the device.

Integrated AVCC Filtering - Previous generations of FTDI’s USB UART devices had a separate AVCC pin - the supply to the internal PLL. This pin required an external R-C ﬁlter. The separate AVCC pin is now connected internally to VCC, and the ﬁlter has now been integrated onto the chip.

Less External Components - Integration of the crystal, EEPROM, USB resistors, and AVCC ﬁlter will substantially reduce the bill of materials cost for USB interface designs using the FT232R compared to its FT232BM predecessor.

Conﬁgurable CBUS I/O Pin Options - There are now 5 conﬁgurable Control Bus (CBUS) lines. Options are TXDEN

- transmit enable for RS485 designs, PWREN# - Power control for high power, bus powered designs, TXLED# - for

pulsing an LED upon transmission of data, RXLED# - for pulsing an LED upon receiving data, TX&RXLED# - which will pulse an LED upon transmission OR reception of data, SLEEP# - indicates that the device going into USB suspend mode, CLK48 / CLK24 / CLK12 / CLK6 - 48MHz, 24MHz,12MHz, and 6MHz clock output signal options. There is also the option to bring out bit bang mode read and write strobes (see below). The CBUS lines can be conﬁgured with any one of these output options by setting bits in the internal EEPROM. The device is supplied with the most commonly used pin deﬁnitions preprogrammed - see Section 8 for details.

Enhanced Asynchronous Bit Bang Mode with RD# and WR# Strobes - The FT232R supports FTDI’s BM chip bit bang mode. In bit bang mode, the eight UART lines can be switched from the regular interface mode to an 8-bit general purpose I/O port. Data packets can be sent to the device and they will be sequentially sent to the interface at a rate controlled by an internal timer (equivalent to the baud rate prescaler). With the FT232R device this mode has been enhanced so that the internal RD# and WR# strobes are now brought out of the device which can be used to allow external logic to be clocked by accesses to the bit bang I/O bus. This option will be described more fully in a separate application note.

Synchronous Bit Bang Mode - Synchronous bit bang mode differs from asynchronous bit bang mode in that the interface pins are only read when the device is written to. Thus making it easier for the controlling program to measure the response to an output stimulus as the data returned is synchronous to the output data. The feature was previously seen in FTDI’s FT2232C device. This option will be described more fully in a separate application note.

CBUS Bit Bang Mode - This mode allows four of the CBUS pins to be individually conﬁgured as GPIO pins, similar to Asynchronous bit bang mode. It is possible to use this mode while the UART interface is being used, thus providing up to four general purpose I/O pins which are available during normal operation. An application note describing this feature is available separately from the FTDI website.

UM232R USB-Serial UART Development Module Datasheet Version 1.02 © Future Technology Devices International Ltd. 2005

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Lower Supply Voltage - Previous generations of the chip required 5V supply on the VCC pin. The FT232R will work with a Vcc supply in the range 3.3V - 5.25V. Bus powered designs would still take their supply from the 5V on the USB bus, but for self powered designs where only 3.3V is available and there is no 5V supply there is no longer any need for an additional external regulator.

Integrated Level Converter on UART Interface and Control Signals - VCCIO pin supply can be from 1.8V to 5V. Connecting the VCCIO pin to 1.8V, 2.8V, or 3.3V allows the device to directly interface to 1.8V, 2.8V or 3.3V and other logic families without the need for external level converter I.C. devices.

5V / 3.3V / 2.8V / 1.8V Logic Interface - The FT232R provides true CMOS Drive Outputs and TTL level Inputs.

Integrated Power-On-Reset (POR) Circuit- The device incorporates an internal POR function. A RESET# pin is

available in order to allow external logic to reset the FT232R where required. However, for many applications the RESET# pin can be left unconnected, or pulled up to VCCIO.

Lower Operating and Suspend Current - The device operating supply current has been further reduced to 15mA, and the suspend current has been reduced to around 70μA. This allows greater margin for peripheral designs to meet the USB suspend current limit of 500μA.

Low USB Bandwidth Consumption - The operation of the USB interface to the FT232R 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 and CBUS I/O pins can be made to drive out at three times the standard signal drive level thus allowing multiple devices to be driven, or devices that require a greater signal drive strength to be interfaced to the FT232R. This option is enabled in the internal EEPROM.

Power Management Control for USB Bus Powered, High Current Designs- The PWREN# signal can be used to directly drive a transistor or P-Channel MOSFET in applications where power switching of external circuitry is required. An option in the internal EEPROM makes the device gently pull down on its UART interface lines when the power is shut off (PWREN# is high). In this mode any residual voltage on external circuitry is bled to GND when power is removed, thus ensuring that external circuitry controlled by PWREN# resets reliably when power is restored.

UART Pin Signal Inversion - The sense of each of the eight UART signals can be individually inverted by setting options in the internal EEPROM. Thus, CTS# (active low) can be changed to CTS (active high), or TXD can be changed to TXD#.

FTDIChip-ID™ - Each FT232R is assigned a unique number which is burnt into the device at manufacture. This ID number cannot be reprogrammed by product manufacturers or end-users. This allows the possibility of using FT232R based dongles 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 describing this feature is available separately from the FTDI website.

Improved EMI Performance - The reduced operating current and improved on-chip VCC decoupling signiﬁcantly improves the ease of PCB design requirements in order to meet FCC, CE and other EMI related speciﬁcations.

Programmable Receive Buffer Timeout - The receive buffer timeout is used to ﬂush remaining data from the receive buffer. This time defaults to 16ms, but is programmable over USB in 1ms increments from 1ms to 255ms, thus allowing the device to be optimised for protocols that require fast response times from short data packets.

Baud Rates - The FT232R supports all standard baud rates and non-standard baud rates from 300 Baud up to 3 Megabaud. Achievable non-standard baud rates are calculated as follows -

Baud Rate = 3000000 / (n + x)

where n can be any integer between 2 and 16,384 ( = 214 ) and x can be a sub-integer of the value 0, 0.125, 0.25,

0.375, 0.5, 0.625, 0.75, or 0.875. When n = 1, x = 0, i.e. baud rate divisors with values between 1 and 2 are not

possible. This gives achievable baud rates in the range 183.1 baud to 3,000,000 baud. When a non-standard baud rate is required simply pass the required baud rate value to the driver as normal, and the FTDI driver will calculate the required divisor, and set the baud rate. See FTDI application note AN232B-05 for more details.

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Extended Operating Temperature Range - The FT232R operates over an extended temperature range of -40º to +85º C thus allowing the device to be used in automotive and industrial applications.

New Package Options - The FT232R is available in two packages - a compact 28 pin SSOP ( FT232RL) and an ultra-compact 5mm x 5mm pinless QFN-32 package ( FT232RQ). Both packages are lead ( Pb ) free, and use a ‘green’ compound. Both packages are fully compliant with European Union directive 2002/95/EC.

Figure 1 - The UM232R Module.

3. UM232R Pin Out and Signal Descriptions

FTDI

TXD

DTR

RTS

VIO

RXD

GND

DSR

DCD

CTS

# CB4

GND

VCC

RST

3V3 CB3 PU

VCC

USB

SLD

1 2 3

2 1

FT232RL

3.1 UM232R Pin Out

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Jumper J1

Jumper J2

Figure 2 - Module Pin Out and Jumper locations.

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