User's Manual

SIM345 EVB User Guide
SIM345-EVB_UGD_V1.02 15.02.2008
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3.5 RS232 Interface
Figure 8: UART1 Serial Port
Main port UART1——A full functional seven-wires serial port
Auxiliary serial port UART2——An auxiliary three-wires serial interface
Main serial port（UART1）:
Pin Signal I/O Description
1 DCD O Data carrier detection
2 TXD1 O Transmit data
3 RXD1 I Receive data
4 DTR I Data Terminal Ready
5 GND GND
7 RTS I Request to Send
8 CTS O Clear to Send
9 RI O Ring Indicator
Figure 9: UART2 Serial Port