FT232R USB UART I.C. Datasheet Version 1.04

© Future Technology Devices International Ltd. 2005

Page 27

9. LED Interface

Any of the 5 CBUS I/O pins can be configured to drive an LED. The FT232R has 3 options for driving an LED - these

are TXLED#, RXLED#, and TX&RXLED#.

Figure 19 -Dual LED Configuration

TXLED#

RXLED#

CBUS[0...4]

CBUS[0...4]

VCCIO

270R

270R

TX

RX

FT232R

TX&RXLED#

CBUS[0...4]

VCCIO

270R

LED

FT232R

Figure 19 illustrates the configuration where one pin is used to indicate transmission of data (TXLED#) and another

is used to indicate receiving data (RXLED#). When data is being transmitted or received the respective pins will drive

from tri-state to low in order to provide indication on the LEDs of data transfer. A digital one-shot time is used so that

even a small percentage of data transfer is visible to the end user.

Figure 20 -Single LED Configuration

In figure 20 the TX&RXLED CBUS option is used. This option will cause the pin to drive a single LED when data is

being transmitted or received by the device.