SAM7X256_14 Datasheet, PDF (317/662 Pages) ATMEL Corporation – ARM-based Flash MCU

30.6.8.2 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 30-29. Programming the transmitter has no effect on the TXD pin. The RXD pin is still connected to the
receiver input, thus the receiver remains active.
Figure 30-29. Automatic Echo Mode Configuration
Receiver
RXD
Transmitter
TXD
30.6.8.3 Local Loopback Mode
Local loopback mode connects the output of the transmitter directly to the input of the receiver, as shown in Figure 30-30.
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 30-30. Local Loopback Mode Configuration
Receiver
RXD
Transmitter
TXD
1
30.6.8.4 Remote Loopback Mode
Remote loopback mode directly connects the RXD pin to the TXD pin, as shown in Figure 30-31. The transmitter and the
receiver are disabled and have no effect. This mode allows bit-by-bit retransmission.
Figure 30-31. Remote Loopback Mode Configuration
Receiver
1
RXD
Transmitter
TXD
SAM7X Series [DATASHEET]
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