Integration Guide

LEON-G100/G200 - System Integration Manual
GSM.G1-HW-09002-F3 Preliminary System description
Page 67 of 101
Name
Description
Remarks
GPIO1
GPIO
Add a test point to provide access to the pin for debugging.
GPIO2
GPIO
Dedicated for connection to a u-blox GPS receiver
Table 28: GPIO pins
GPIO1 and GPIO2 pins ESD rating is 1 kV (contact discharge). A higher protection level could be
required if the lines are externally accessible on the application board. A higher protection level can be
achieved mounting an ESD protection (e.g. EPCOS CA05P4S14THSG varistor array) on the lines
connected to these pins if they are externally accessible on the application board.
GPIO2 is dedicated for connection to a u-blox GPS receiver: GPIO2 is driven as output by the +UGPS AT
command to switch-on or switch-off the u-blox GPS receiver.
If LEON-G100/G200 module is connected to a u-blox GPS receiver by the DDC (I
2
C) interface, GPIO2 must be
connected to the active-high enable pin (or the active-low shutdown pin) of the voltage regulator that supplies
the u-blox GPS receiver on the application board.
If LEON-G100/G200 module is not connected to a u-blox GPS receiver by the DDC (I
2
C) interface, GPIO2 can be
used for general purposes.
To avoid an increase of module power consumption any external signal connected to a GPIO must be
set low or tri-stated when the module is in power-down mode. If the external signals in the application
circuit connected to a GPIO cannot be set low or tri-stated, mount a multi channel digital switch (e.g.
Texas Instruments SN74CB3Q16244) or a single channel analog switch (e.g. Texas Instruments
TS5A3159 or TS5A63157) between the two-circuit connections and set to high impedance.
If the GPIO1 and GPIO2 pins are not used, they can be left floating on the application board.
For debug purposes, add a test point on the GPIO1 pin even if this GPIO is not used.