User's Manual

SIM548C EVB User Guide
SIM548C-EVB_ UGD _V1.01 04.05.2008
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3.5 RS232 interface
3.5.1 GSM part
Figure 9: GSM part serial ports
Serial Port 1
Pin Signal I/O Description
1 DCD O Data carrier detection
2 TXD O Transmit data
3 RXD 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
Serial Port 2
Pin Signal I/O Description
2 DEBUG_TX O Transmit data
3 DEBUG_RX I Receive data
5 GND GND