User's Manual

SIM548C EVB User Guide
SIM548C-EVB_ UGD _V1.01 04.05.2008
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4 Test interface
Figure 13: Test interface overview
4.1 GSM serial ports
Figure 14: GSM serial ports
Pin Signal I/O Description
1 TXD O Transmit data
2 RXD I Receive data
3 DCD O Data carrier detection
4 RI O Ring Indicator
5 CTS O Clear to Send
6 GND GND
7 DTR I Data Terminal Ready
8 DEBUG_RX I Receive data