Atmel Xplained Evaluation Board AT32UC3A3-XPLD AT32UC3A3-XPLD Data Sheet

32072H–AVR32–10/2012

Figure 25-55. Automatic Echo Mode Configuration

Local loopback mode connects the output of the transmitter directly to the input of the receiver,
as shown in 

. The TXD and RXD pins are not used. The RXD pin has no effect on

the receiver and the TXD pin is continuously driven high, as in idle state.

Figure 25-56. Local Loopback Mode Configuration

Remote loopback mode connects the RXD pin to the TXD pin, as shown in 

. The

transmitter and the receiver are disabled and have no effect. This mode allows bit-by-bit
retransmission.

Figure 25-57. Remote Loopback Mode Configuration

Receiver

Transmitter

RXD

TXD

Receiver

Transmitter

RXD

TXD

1

Receiver

Transmitter

RXD

TXD

1

–

–

MANEA

23

22

21

20

19

18

17

16

–

–

–

MANE

CTSIC

DCDIC

DSRIC

RIIC

15

14

13

12

11

10

9

8

LINTC

LINIR

NACK

RXBUFF

–

ITER/UNRE

TXEMPTY

TIMEOUT