Telit Wireless Solutions GE864 Work Light User Manual


 
GE864 Hardware User Guide
1vv0300694 Rev.10 - 10/06/08
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved page 32 of 69
7.1 Reset signal
Signal Function I/O Bga Ball
RESET Phone reset I A2
RESET is used to reset the GE864-QUAD / PY modules. Whenever this signal is pulled low, the GE864-
QUAD / PY is reset. When the device is reset it stops any operation. After the release of the reset
GE864-QUAD / PY 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 GE864-QUAD / PY. Use the ON/OFF signal to perform this
function or the AT#SHDN command.
Reset Signal Operating levels:
Signal Min Max
RESET Input high 2.0V* 2.2V
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.