GL865 Hardware User Guide
1vv0300910 Rev.1 – 2011-07-22
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved
page 39 of 79
8.1.
Reset signal
Signal
Function
I/O
pin
RESET*
Phone reset I
47
RESET* is used to reset the GL865.
Whenever this signal is pulled
low, the GL865 is reset. When the device is reset it stops any
operation.
After
the
release
of
the
reset
GL865
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 GL865. Use the ON/OFF
procedure to perform this function.
Reset Signal Operating levels:
Signal
Min
Max
RESET* Input high
1.8V(NOTE
1)
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.
