GE866-QUAD Hardware User Guide
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Page 43 of 82
Mod. 0805 2011-07 Rev.2
8.1.
Reset signal
Signal
Function
I/O
pin
RESET*
Phone reset
I
G4
RESET* is used to reset the GE866-QUAD. Whenever this signal is pulled low, the
GE866-QUAD is reset. When the device is reset it stops any operation. After the
release of the reset GE866-QUAD 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 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 GE866-QUAD. Use the ON/OFF procedure to
perform this function.
Signal
Min
Max
RESET* Input high
1.8V(NOTE1) 2.1V
RESET* Input low
0V
0.2V
(NOTE1) 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.