SIM508 EVB User Guide
SIMCOM
4.4 GPS control & I/O
Figure 17: GPS control & I/O interface
Pin
Signal
I/O
Description
1
GPS_ON_OFF
I
GPS ON/OFF key
2 GPS_GPIO0 I/O
Reserved.
3 GPS_BOOTSEL I
For re-programming the Flash, it must be set to
High
4 GPS_GPIO4 I/O
Reserved.
5
GPS_MRST
I
Reset pin of the GPS part, active low.
6 GPS_GPIO8 I/O
Reserved.
7 GPS_TIMEMARK O
1 PPS timemark output for synchronizing to within
1 microsecond of GPS time.
8 GPS_GPIO13 I/O
Reserved.
9 GPS_FREQ_XFER
I
External CMOS clock source. This pin applies to the
SiRFLoc Client firmware, if unused, keep floating
10 GPS_GPIO14 I/O
Reserved.
11 GND
GND
12 GPS_TIMERSYNC I
External CMOS clock source. This pin applies to the
SiRFLoc Client firmware, if unused, keep floating
13 GND
GND
14
GPS_VCC
I
GPS part power supply
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