Datasheet

Table Of Contents
387
SAM7S Series [DATASHEET]
6175M–ATARM–26-Oct-12
31.6.8.2 Automatic Echo Mode
Automatic echo mode allows bit-by-bit retransmission. When a bit is received on the RXD pin, it is sent to the TXD
pin, as shown in Figure 31-31. Programming the transmitter has no effect on the TXD pin. The RXD pin is still con-
nected to the receiver input, thus the receiver remains active.
Figure 31-31. Automatic Echo Mode Configuration
31.6.8.3 Local Loopback Mode
Local loopback mode connects the output of the transmitter directly to the input of the receiver, as shown in Figure
31-32. The TXD and RXD pins are not used. The RXD pin has no effect on the receiver and the TXD pin is contin-
uously driven high, as in idle state.
Figure 31-32. Local Loopback Mode Configuration
31.6.8.4 Remote Loopback Mode
Remote loopback mode directly connects the RXD pin to the TXD pin, as shown in Figure 31-33. The transmitter
and the receiver are disabled and have no effect. This mode allows bit-by-bit retransmission.
Figure 31-33. Remote Loopback Mode Configuration
Receiver
Transmitter
RXD
TXD
Receiver
Transmitter
RXD
TXD
1
Receiver
Transmitter
RXD
TXD
1