FT2232D datasheet(33/56 Pages) FTDI

33 / 56 page

DS2232D Version 0.91

FT2232D Dual USB UART / FIFO I.C.

9.2 232 UART Mode LED Interface

Figure 1

Dual LED Configuration

Figure 1

Single LED Configuration

FT2232C

TXLED#

RXLED#

VCCIO

220R

LED

FT2232C

TXLED#

RXLED#

VCCIO

220R

When configured in UART mode the FT2232D has two IO pins on each channel dedicated to controlling LED

status indicators, one for transmitted data the other for received data. When data is being transmitted / received

the respective pins drive from tri-state to low in order to provide indication on the LED’s of data transfer. A digital

one-shot timer is used so that even a small percentage of data transfer is visible to the end user. Figure 17 shows

a configuration using two individual LED’s – one for transmitted data the other for received data. In Figure 18, the

transmit and receive LED indicators are wire-OR’ed together to give a single LED indicator which indicates any

transmit or receive data activity.

Another possibility (not shown here) is to use a 3 pin common anode tri-color LED based on the circuit in Figure 18 to

have a single LED that can display activity in a variety of colors depending on the ratio of transmit activity compared to

receive activity.

Note that the LED’s are connected to the same supply as VCCIO.

FT2232D

FT2232D Datasheet(PDF) 33 Page - Future Technology Devices International Ltd.