GE865 Hardware User Guide
1vv0300799 Rev.9 – 27-07-2009
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved
page 36 of 70
8.1 Reset signal
Signal
Function
I/O
Bga Ball
RESET# Phone reset
I
C1
RESET# is used to reset the
GE865
. Whenever this signal is pulled low, the GE865 is
reset. When the device is reset it stops any operation. After the release of the reset
GE865 is unconditionally shut down, without doing any detach operation from the
network where it is registered. This behaviour is not a proper shut down because any
GSM device is requested to issue a detach request on turn off. For this reason the
Reset signal must not be used to normally shutting down the device, but only as an
emergency exit in the rare case the device remains stuck waiting for some network
response.
The RESET# is internally controlled on start-up to achieve always a proper power-on
reset sequence, so there's no need to control this pin on start-up. It may only be used
to reset a device already on that is not responding to any command.
NOTE:
Do not use this signal to power off the GE865. Use the ON/OFF signal to perform this
function or the AT#SHDN command.
Reset Signal Operating levels
:
Signal
Min
Max
RESET Input high
1.8V*
2.1V
RESET Input low
0V
0.2V
* this signal is internally pulled up so the pin can be left floating if not used.
If unused, this signal may be left unconnected. If used, then it
must always be
connected with an open collector transistor
, to permit to the internal circuitry the
power on reset and under voltage lockout functions.
