Atmel ARM-Based Evaluation Kit AT91SAM9N12-EK AT91SAM9N12-EK Data Sheet
Product codes
AT91SAM9N12-EK
800
SAM9N12/SAM9CN11/SAM9CN12 [DATASHEET]
11063K–ATARM–05-Nov-13
40.7.9.2 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
shown in
. 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 40-55. Automatic Echo Mode Configuration
40.7.9.3 Local Loopback Mode
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.
high, as in idle state.
Figure 40-56. Local Loopback Mode Configuration
40.7.9.4 Remote Loopback Mode
Remote loopback mode directly 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 40-57. Remote Loopback Mode Configuration
Receiver
Transmitter
RXD
TXD
Receiver
Transmitter
RXD
TXD
1
Receiver
Transmitter
RXD
TXD
1