M16 EVB User Guide
3.4. Serial port
Figure 6: Serial port
Table 7: Pins of Serial Port 0
Pin
Signal
I/O
Description
1 DCD0 O
Data carrier detection
2 TXD0 O
Transmit data
3 RXD0 I
Receive data
4 DTR0 I
Data terminal ready
5 GND
GND
7 RTS0 I
Request to send
8 CTS0 O
Clear to send
9 RI0 O
Ring indicator
The voltage level of these signals has been shifted to RS-232 level, so it can be directly connect to
PC by USB to UART converter cable. This port is used for AT command, GPRS data, CSD FAX,
multiplexing function and firmware upgrade.
M16_EVB_UGD_V1.01
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