FT232R USB UART I.C. Datasheet Version 1.04

© Future Technology Devices International Ltd. 2005

Page 26

8.4 USB to MCU UART Interface

Figure 18 -Example USB to MCU UART Interface

Figure 18 is an example of interfacing the FT232R to a Microcontroller (MCU) UART interface. This example uses

TXD and RXD for transmission and reception of data, and RTS# / CTS# hardware handshaking. Also in this example

CBUS0 has been configured as a 12MHz output which is being used to clock the MCU.

Optionally, RI# can be connected to another I/O pin on the MCU and could be used to wake up the USB host

controller from suspend mode. If the MCU is handling power management functions, then a CBUS pin can be

configured as PWREN# and should also be connected to an I/O pin of the MCU.

FT232R

A

G

N

D

G

N

D

G

N

D

G

N

D

T

E

S

T

100nF

3V3OUT

VCCIO

NC

RESET#

NC

+

100nF

4.7uF

Vcc

RXD

TXD

RTS#

CTS#

DTR#

DSR#

DCD#

RI#

CBUS0

CBUS3

CBUS2

CBUS1

USBDP

USBDM

VCC

1

2

3

4

5

OSCI

OSCO

CBUS4

PWREN#

TXD

RXD

CTS#

RTS#

CLK_IN

I/O

Ferrite

Bead

GND

GND

GND

+

GND

10nF

12MHz

OUT

Vcc

Vcc